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Aim: To investigate the possible effect of haemodialysis (HD) on the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of evogliptin, a dipeptidyl peptidase‐4 (DPP‐4) inhibitor. Methods: A single‐dose, open‐label, parallel‐group study of eight end‐stage renal disease (ESRD) patients and eight matched healthy subjects was conducted. ESRD patients received a single oral dose of evogliptin 5 mg after and before HD with a 2‐week washout between each dose, and healthy subjects received a single oral dose of evogliptin 5 mg. Serial blood, dialysate, and urine samples were collected to assess the PK and PD profiles of evogliptin. To compare PK parameters before and after HD, geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were calculated. Results: The GMRs for the maximum concentration and area under the concentration‐time curve from time 0 to the last measurable timepoint (AUClast) of evogliptin when administered before HD compared with after HD were 0.7293 (90% CI 0.6171‐0.8620) and 0.9480 (90% CI 0.8162‐1.1010), respectively. The maximum DPP‐4 inhibitory effect, area under the DPP‐4 inhibitory effect‐time curve, and time duration of more than 80% DPP‐4 inhibition were comparable when evogliptin was administered before and after HD. Compared with healthy subjects, the mean AUClast of evogliptin was approximately 1.4‐fold greater in ESRD patients, but the difference is unlikely to affect the safety and efficacy of evogliptin. Conclusion: The effect of HD on the PK and PD characteristics of evogliptin was not clinically significant; therefore, dose adjustment according to HD status is not necessary. [ABSTRACT FROM AUTHOR]

Background: Cardiopulmonary bypass can affect the pharmacokinetics of anesthetic agents. Aims: We aimed to evaluate the pharmacokinetics of dexmedetomidine for infants and small children undergoing cardiac surgery with cardiopulmonary bypass based on population pharmacokinetics. Methods: We enrolled 30 pediatric cardiac surgical patients in this study. After anesthetic induction with atropine (0.02 mg/kg), thiopental sodium (5 mg/kg), and fentanyl (2–3 μg/kg), we administered 1 μg/kg of dexmedetomidine for 10 min, followed by administration of 0.5 μg/kg of dexmedetomidine per hour during surgery. At the initiation of cardiopulmonary bypass, 1 μg/kg of dexmedetomidine was infused over 5 min. Arterial blood was obtained at predefined time points. A pharmacokinetic model was developed using NONMEM. Theory‐based allometric scaling with fixed exponents was applied. Weight, age, post‐menstrual age, fat‐free mass, whether to implement cardiopulmonary bypass and temperature were explored as covariates. Results: A total of 376 blood samples were obtained from 29 children (age: 20.3 ± 19.3 months, weight: 9.7 ± 4.1 kg). A two‐compartment mammillary model with third compartment associated cardiopulmonary bypass procedure best explained the pharmacokinetics of dexmedetomidine. The pharmacokinetic parameter estimates (95% CI) standardized to a 70‐kg person were as follows: V1 (L) = 31.6 (17.9–39.5), V2 (L) = 90.1 (44.0–330), Cl (L/min) = 1.08 (0.70–1.25), Q (L/min) = 2.0 (1.05–3.46). Volume for third compartment associated cardiopulmonary bypass procedure (L) = 39.4 (19.3–50.9). Clearance was not influenced by the presence of cardiopulmonary bypass in this model. Conclusion: When cardiopulmonary bypass is applied, the plasma concentration of dexmedetomidine decreases due to an increase in the volume of distribution, so a loading dose is required to maintain the previous concentration. [ABSTRACT FROM AUTHOR]

Eslicarbazepine acetate (ESL) is a prodrug antiseizure medication for the treatment of focal seizures. ESL shows a well‐established pharmacokinetic (PK)‐pharmacodynamic relationship and has similar extrinsic epilepsy‐related factors across ethnicities. This study evaluated and compared ESL safety, tolerability, and PK characteristics between Korean and White subjects. A randomized, double‐blind, placebo‐controlled, single‐ and multiple‐dose escalation study was conducted in healthy Korean and White adults. Participants randomly received a single dose and multiple oral doses of ESL (400–1600 mg) or placebo once daily for 11 days at a ratio of 8:2. Serial blood samples were collected to determine the plasma concentration of ESL and its metabolites (eslicarbazepine, [R‐licarbazepine and oxcarbazepine). Safety and tolerability were assessed throughout the study. A total of 29 Korean and 20 White subjects completed the study. The PK profiles of the metabolites of ESL were similar between Korean and White subjects. The geometric mean ratio (90% confidence interval) of Korean to White subjects for the area under the concentration–time curve within a dosing interval of eslicarbazepine was 1.06 (0.97–1.17) and 0.96 (0.87–1.06) after multiple oral doses of 400 and 1600 mg ESL, respectively. Other PK parameters were also similar between the two ethnic groups. ESL was well‐tolerated in healthy Korean and White subjects, and its PK characteristics were similar between the two ethnic groups. The results of this study support to use the same dosage regimen of ESL in both White and Korean patients with seizures. [ABSTRACT FROM AUTHOR]

A long‐acting granulocyte colony‐stimulating factor, tripegfilgrastim, was approved in Korea for the prevention of chemotherapy‐induced neutropenia in adult patients. In this study, we evaluated the pharmacokinetics, pharmacodynamics, and safety of tripegfilgrastim in pediatric patients. A phase I, open‐label, single ascending‐dose study was performed in pediatric patients with solid tumors or lymphoma (ClinicalTrials.gov, NCT02963389). The patients were stratified according to age groups (aged 6 to 12 or 12 to 19 years) and received a single subcutaneous dose of tripegfilgrastim 60 μg/kg or 100 μg/kg. Tripegfilgrastim was administered 24 hours after the end of the chemotherapy, and serial blood sampling and safety monitoring were conducted. Twenty‐seven patients with solid tumors were enrolled in this study. Tripegfilgrastim was detectable in plasma for an extended period (terminal half‐life > 40 hours), and plasma concentrations increased slightly less than dose proportionally. The mean duration of grade 4 neutropenia was reduced as the average tripegfilgrastim concentration during the initial neutrophil recovery process increased. No substantial differences in the pharmacokinetic and pharmacodynamic responses were observed between the two age groups. When stratified by body weight, weighing more than 45 kg has a higher risk of a prolonged neutropenia period when receiving the lower dose (60 μg/kg) of tripegfilgrastim. Tripegfilgrastim was generally safe and well‐tolerated in the pediatric patients. These results justify further clinical investigations of tripegfilgrastim at 100 μg/kg dose in pediatric patients. [ABSTRACT FROM AUTHOR]

To investigate pharmacokinetic and pharmacodynamic differences of zolpidem between males and females and their causes, including CYP3A4 activity. A single oral dose of zolpidem (10 mg) was administered to 15 male and 15 female healthy subjects. Blood samples were collected up to 12 h post-dose to determine plasma zolpidem concentrations. Pharmacokinetic parameters were obtained using non-compartmental analysis. Digit symbol substitution test, choice reaction time, and visual analog scale of sleepiness were used to evaluate pharmacodynamics. We measured CYP3A4 activity using 4β-hydroxycholesterol, an endogenous metabolite. Mean maximum plasma concentration and area under the plasma concentration–time curve were higher for females than for males (9.9% and 32.5%, respectively); other pharmacokinetic parameters showed no significant differences. Pharmacodynamic scores for females showed delayed recovery compared with that for males. CYP3A4 activity was higher in females than in males (p = 0.030). There was no serious adverse event, and adverse event incidence was not different between the sexes. Zolpidem exposure was about 30% higher in females than in males. Delayed pharmacodynamic score recovery in females could be related to higher zolpidem concentrations. Although apparent clearance was lower in females, systemic clearance might not be the cause of the different exposures to zolpidem. [ABSTRACT FROM AUTHOR]

Ursodeoxycholic acid (UDCA) is a secondary bile acid that is used to treat primary biliary cholangitis. Although UDCA has a hepatoprotective effect in some diseases, its benefit in nonalcoholic fatty liver disease (NAFLD) remains controversial. We aimed to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of UDCA in overweight subjects with elevated liver enzymes after multiple administrations of UDCA and compare these changes with vitamin E treatment. Overweight subjects (body mass index, 25‐30 kg/m2) with elevated alanine aminotransferase (ALT) level (40‐200 IU/L) were enrolled. Subjects received one of the following three 8‐week treatments: UDCA 300 mg twice daily UDCA 300 mg twice daily for 4 weeks followed by UDCA 300 mg twice daily and metformin 500 mg twice daily for 4 weeks, and vitamin E 400 IU twice daily. PK and PD (liver function, lipid profiles, insulin sensitivity, and miR‐122) analyses were performed. Thirty subjects were enrolled; 1 subject withdrew his consent during the study. The PK characteristics were similar to those of healthy volunteers. The ALT and miR‐122 levels decreased in the UDCA groups, whereas the ALT and aspartate aminotransferase levels decreased in the vitamin E group. The lipid profiles and insulin sensitivity did not show significant changes among the groups. There was no serious adverse event, and the safety profiles were similar among the treatment groups. The liver enzyme and miR‐122 levels were decreased by UDCA. Considering UDCA and vitamin E have a hepatoprotective effect and different mechanisms of action, combination therapy could be an option for NAFLD. [ABSTRACT FROM AUTHOR]

The pharmacokinetic (PK) properties of drugs are affected in several ways by interactions with microbiota. The aim of this study was to investigate the effects of oral vancomycin on the gut microbiota and, consequently, on the PKs of simvastatin. An open‐label, single arm, sequential crossover study was conducted in six healthy Korean male subjects. After 6 days on a control diet, simvastatin 40 mg was orally administered to the subjects before and after 1 week of oral vancomycin treatment. Blood samples for PK analysis and fecal samples for metagenomic and metabolomic analyses were collected. After vancomycin treatment, the richness of microbiota considerably decreased, and the composition was altered. In particular, the relative abundance of Bacteroidetes decreased, whereas that of proteobacteria increased. In addition, changes in fecal metabolites, including D‐glucuronic acid, were observed. However, systemic exposure of simvastatin was not changed whereas that of hydroxysimvastatin showed a tendency to increase. The relationship between the change of PKs of simvastatin and the change of gut microbiota and fecal metabolites were not clearly observed. [ABSTRACT FROM AUTHOR]

A lack of information regarding whether genetic polymorphisms of SLCO1B1 and ABCG2 affect the pharmacokinetics (PKs)/pharmacodynamics (PDs) of rosuvastatin in elderly subjects prevents optimal individualized pharmacotherapy of rosuvastatin in clinical settings. This study aimed to investigate the effect of age and genetic polymorphisms and possible differences in genetic effects on the PKs/PDs of rosuvastatin between elderly and young subjects. Two separate clinical studies designed as open-label, one-sequence studies with multiple-dose administration for elderly (n = 20) and young (n = 32) subjects were conducted. All subjects received 20 mg of rosuvastatin once daily for 21 days. The exposure to rosuvastatin, characterized by the area under the time curve (AUC), increased by 23% in the elderly subjects compared with that of young subjects, which was not significant. When compared to the subjects with breast cancer resistance protein (BCRP) normal function, the exposure to rosuvastatin increased by 44% in young subjects (p = 0.0021) with BCRP intermediate function (IF) and by 35% and 59% (p > 0.05 for both) in elderly subjects with BCRP IF and low function, respectively. SLCO1B1 521T > C was also partially associated with a higher AUC of rosuvastatin in young subjects and a less pronounced increasing trend in elderly subjects (p > 0.05 for both). The lipid-lowering effect of rosuvastatin was less pronounced in the elderly subjects than in the young subjects, and genetic polymorphisms of neither SLCO1B1 nor ABCG2 significantly affected the PDs of rosuvastatin. The ABCG2 421C > A polymorphism was associated with the PKs of rosuvastatin and was identified as a more important determinant than the SLCO1B1 521T > C polymorphism in both elderly and young subjects. [ABSTRACT FROM AUTHOR]

Ursodeoxycholic acid (UDCA) is a secondary bile acid component used for treating primary biliary cirrhosis. This study evaluated and compared the pharmacokinetic (PK) profiles of UDCA and its conjugates glyco‐UDCA (G‐UDCA) and tauro‐UDCA (T‐UDCA) in healthy elderly subjects and younger adults. In this randomized, open‐label, 2‐treatment, 1‐sequence, and parallel study, subjects received 400 or 800 mg UDCA on day 1, followed by 200 mg UDCA twice daily for 2 weeks. Blood samples were obtained up to 24 hours after the first UDCA dose. Changes in miRNA‐122, γ‐glutamyl transferase, aspartate aminotransferase, and alanine aminotransferase levels from baseline were assessed to determine the safety and pharmacological effects of UDCA. This study examined the outcomes of 16 elderly subjects and 16 younger adults. Dose‐normalized peak concentration of and systemic exposure to UDCA were 2 to 4 times higher, and the corresponding values of G‐UDCA and T‐UDCA were 1.7 times higher in the elderly subjects than in the younger adults. The subjects in both groups showed multiple peak profiles of UDCA and its conjugates. The miRNA‐122 levels and hepatic enzyme test results were within the normal range in the elderly subjects after multiple administration of UDCA. This study is the first to confirm that the PK measurements of UDCA were higher in elderly subjects than in younger adults, which may improve the clinical outcomes of elderly subjects. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to explore the pharmacokinetic-pharmacodynamic (PK-PD) relationship of metformin on glucose levels after the administration of 250 mg and 1000 mg of metformin in healthy volunteers. Methods: A total of 20 healthy male volunteers were randomized to receive two doses of either a low dose (375 mg followed by 250 mg) or a high dose (1000 mg followed by 1000 mg) of metformin at 12-h intervals. The pharmacodynamics of metformin was assessed using oral glucose tolerance tests before and after metformin administration. The PK parameters after the second dose were evaluated through noncompartmental analyses. Four single nucleotide polymorphisms in MATE1, MATE2-K, and OCT2 were genotyped, and their effects on PK characteristics were additionally evaluated. Results: The plasma exposure of metformin increased as the metformin dose increased. The mean values for the area under the concentration-time curve from dosing to 12 hours post-dose (AUC0-12h) were 3160.4 and 8808.2 h·μg/L for the low- and high-dose groups, respectively. Non-linear relationships were found between the glucose-lowering effect and PK parameters with a significant inverse trend at high metformin exposure. The PK parameters were comparable among subjects with the genetic polymorphisms. Conclusions: This study showed a non-linear PK-PD relationship on plasma glucose levels after the administration of metformin. The inverse relationship between systemic exposure and the glucose-lowering effect at a high exposure indicates a possible role for the intestines as an action site for metformin. Trial registration: ClinicalTrials.gov [ABSTRACT FROM AUTHOR]

Aims The purpose of this study was to explore clinical markers reflecting developmental changes in drug clearance by preterm infants. Methods Preterm infants administered aminophylline or theophylline to treat apnoea of prematurity were enrolled in this study. Trough and one of 2 h, 4 h or 6 h post-dose blood samples and urine samples were collected during steady state, to determine the concentrations of theophylline and its targeted metabolites. CYP1A2*1C and CYP1A2*1F genotypes were analyzed. Total, renal and nonrenal clearances of theophylline were calculated, and cytochrome P450 1A2 (CYP1A2) activity was obtained from the ratio of 1-methyluric acid and 3-methylxanthine to theophylline in urine. Multiple linear regression analysis was performed to evaluate the relationships between theophylline clearance and the clinical characteristics of preterm infants. Results A total of 152 samples from 104 preterm infants were analyzed. A strong association between the serum trough and urine theophylline concentrations was found ( P < 0.001). Total, renal and nonrenal clearances of theophylline were 0.50 ± 0.29 ml kg−1 min−1, 0.16 ± 0.06 ml kg−1 min−1 and 0.34 ± 0.28 ml kg−1 min−1, respectively. CYP1A2 activity correlated positively with the postnatal age and postmenstrual age. However, CYP1A2 genotype was not associated with CYP1A2 activity, which was significantly associated with nonrenal clearance. CYP1A2 activity, postnatal age , weight and 24-h urine output were significantly associated with total theophylline clearance. Conclusions CYP1A2 activity can be monitored using noninvasive random urine samples, and it can be used to assess developmental changes in theophylline clearance by preterm infants. [ABSTRACT FROM AUTHOR]

Background: Human carboxylesterase 1 (CES1) is a serine esterase that hydrolyses various exogenous and endogenous compounds including oseltamivir, a prodrug used to treat influenza. A novel CES1 c.662A>G single nucleotide polymorphism (SNP) was predicted to decrease CES1 enzymatic activity in an in silico analysis. This study evaluated the effect of the c.662A>G SNP on the pharmacokinetics (PK) of oseltamivir in humans. Methods: A single oral dose of oseltamivir at 75 mg was administered to 20 healthy subjects, 8 heterozygous c.662A>G carriers (c.662AG) and 12 non-carriers (c.662AA). The concentrations of oseltamivir and its active metabolite, oseltamivir carboxylate, were measured in plasma and urine using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The PK parameters were calculated using a noncompartmental method. The geometric mean ratios (GMR, c.662AG to c.662AA) of the PK parameters and their 90% confidence intervals (CI) were calculated. Results: The systemic exposure to oseltamivir, as assessed by the AUC0-48h of oseltamivir, was increased by 10% in c.662AG subjects, whereas the AUC0-48h of oseltamivir carboxylate was 5% lower in c.662AG subjects. The GMR and 90% CI of the metabolic ratio (AUC0-48h, Oseltamivir carboxylate/AUC0-48h, Oseltamivir) was 0.87 (0.66–1.14). The amount of unchanged oseltamivir excreted in the urine was increased by 15% in subjects with the c.662AG genotype. Conclusions: This result suggests that CES1 enzymatic activity may be decreased in these heterozygous allele carriers, although further studies are warranted to investigate the clinical implications of this genetic variation on CES1 substrate drugs. Trial registration: ClinicalTtrials.gov [ABSTRACT FROM AUTHOR]

Aims The aim of this study was to develop a population pharmacokinetic (PK) model of udenafil and its active metabolite, DA-8164, in healthy subjects and patients with hepatic impairment (HI) and to estimate the optimal dosing recommendations for patients with HI. Methods An open label, three parallel group, age and weight matched control study was conducted in 18 volunteers, six healthy subjects ( n = 6) and patients with mild (Child-Pugh class A, n = 6) and moderate HI (Child-Pugh class B, n = 6). Serial blood samples were collected for up to 72 h after a single administration of udenafil 100 mg. A population PK model was developed using non-linear mixed effects modelling ( nonmem, ver. 7.2). The simulated data from the final PK model and original data of healthy subjects were compared to identify the optimal dose for patients with HI. Results A two compartment model for both udenafil and DA-8164 best described the data. Prothrombin time on metabolic clearance of udenafil to DA-8164 was included in the final model as a covariate. Compared with the AUC(0, tlast) value after administration of udenafil 100 mg to healthy subjects, the geometric mean ratios (95% confidence interval) after 100 mg and 75 mg udenafil administration were 1.21 (1.10, 1.32) and 0.74 (0.67, 0.81) in patients with mild HI, respectively. Meanwhile, those were 1.55 (1.43, 1.67) and 1.02 (0.92, 1.12) in patients with moderate HI, respectively. Conclusions This study suggests that the recommended doses of udenafil are 100 mg and 75 mg in patients with mild and moderate HI, respectively. [ABSTRACT FROM AUTHOR]

AIMS HM30181 is a third generation P-glycoprotein (P-gp) inhibitor currently under development. The objectives of this study were to evaluate the effects of a single dose of HM30181 on the pharmacodynamics and pharmacokinetics of loperamide, a P-gp substrate, and to compare them with those of quinidine. METHODS Eighteen healthy male subjects were administered loperamide alone (period 1) or with loperamide plus quinidine or HM30181 in period 2 or 3, respectively. In period 3, subjects randomly received one of three HM30181 doses: 15, 60 or 180 mg. Changes in pupil size, alertness, oxygen saturation and the oral bioavailability of loperamide were assessed in each period. In addition, the pharmacokinetics of HM30181 were determined. RESULTS Pupil size, alertness and oxygen saturation did not change over time when loperamide alone or loperamide plus HM30181 was administered while HM30181 significantly increased the systemic exposure to loperamide, i.e. the geometric mean ratio (90% confidence interval) of AUC(0,t/ast) for loperamide with and without HM30181 was 1.48 (1.08, 2.02). Co-administered quinidine significantly increased the systemic exposure to loperamide 2.2-fold (1.53, 3.18), which also markedly reduced pupil size, resulting in a decrease of 24.7 mm h in the area under the effect curve of pupil size change from baseline compared with loperamide alone. CONCLUSIONS HM30181 inhibits P-gp mainly in the intestinal endothelium, which can be beneficial because pan-inhibition of P-gp, particularly in the brain, could lead to detrimental adverse events. Further studies are warranted to investigate adequately the dose-exposure relationship of HM30181, along with its duration of effect. [ABSTRACT FROM AUTHOR]

Background and Objectives: Lobeglitazone is a recently approved peroxisome proliferator-activated receptor-γ agonist for the treatment of type 2 diabetes mellitus in Korea. The purpose of this study was to investigate the pharmacokinetic properties of lobeglitazone in healthy females and to compare these with historical data in healthy males. Methods: This study was designed as a block-randomized, double-blind, placebo-controlled, parallel-group study. A single 2 or 4 mg oral dose of lobeglitazone or a placebo was randomly administered to 22 female subjects, and pharmacokinetic blood samples were obtained after dosing. Pharmacokinetic parameters were calculated by a non-compartmental method, and the results were compared with those previously obtained from male subjects. Tolerability was assessed by clinical and laboratory parameters. Results: During the study, a total of 28 adverse events (AEs) were observed in the lobeglitazone group ( n = 16) and nine AEs in the placebo group ( n = 6). Serious AEs or significant clinical changes were not observed. After oral administration, lobeglitazone was rapidly absorbed with the time to maximum plasma concentration ( t) ranging from 0.5 to 4.0 h. The mean (standard deviation) maximum plasma concentration ( C) and area under the plasma concentration-time curve from time zero to infinity (AUC) for the 2 mg dose were 214.8 (56.4) µg/L and 2,251.3 (721.2) µg·h/L, respectively, and the corresponding values for the 4 mg dose were 310.0 (47.8) µg/L and 6,942.6 (1,778.9) µg·h/L, respectively. The ratios (95 % CIs) for the geometric means (female/male) of the C and AUC were 1.23 (0.89-1.69) and 1.11 (0.73-1.68), respectively (2 mg), and 1.28 (1.01-1.63) and 2.36 (1.60-3.47), respectively (4 mg). Conclusion: Lobeglitazone was well-tolerated in healthy females. There was no sex difference for systemic lobeglitazone exposure at a 2 mg dose; however, female subjects showed greater systemic exposure than males after the administration of 4 mg of lobeglitazone. In spite of the pharmacokinetic difference, dose adjustment based on sex alone is not needed in clinical use because therapy should be individualized for each patient to achieve glycemic control. [ABSTRACT FROM AUTHOR]

Background and Objectives: GC1113, a hybrid Fc-fused erythropoietin, is a novel erythropoiesis-stimulating agent that is expected to have an extended duration of action. The preclinical data showed that the hemoglobin increase lasted longer following GC1113 administration than it did following the administration of darbepoetin alfa (NESP). This study aimed to investigate the pharmacodynamic and pharmacokinetic characteristics and tolerability profiles of GC1113 in humans after single intravenous or subcutaneous administration and to compare the results with those for darbepoetin alfa. Methods: A dose-block randomized, placebo- and active-controlled, dose-escalation phase I clinical trial was conducted in 96 healthy volunteers. Blood samples were collected before and up to 672 h after drug administration and the serum erythropoietin concentration following the GC1113 or darbepoetin alfa administration was measured by an ELISA. The reticulocyte counts were measured for pharmacodynamic assessments. Pharmacokinetic and pharmacodynamic parameters were determined using non-compartmental methods. Results: The reticulocyte count-time profiles in the intravenous GC1113 3-5 μg/kg groups were comparable with those of the darbepoetin alfa 30 μg group. After subcutaneous administration of GC1113, reticulocyte count peaked later and decreased more slowly than it did following darbepoetin alfa administration. GC1113 (0.3-5 μg/kg intravenous, 1-8 μg/kg subcutaneous) was well-tolerated in the volunteers, and no immunogenicity was observed. Conclusion: GC1113 was tolerated and effective in the studied dose range; these findings could be applied to further clinical studies with patients. [ABSTRACT FROM AUTHOR]

Background and Objective: Gemigliptin is a novel dipeptidyl peptidase-4 (DPP-4) inhibitor used in the treatment of type 2 diabetes mellitus. This study evaluated possible pharmacodynamic and pharmacokinetic interactions between gemigliptin and metformin and investigated their tolerability. Methods: A randomized, open-label, multiple-dose, three-treatment, three-period, three-sequence crossover study was conducted in healthy male subjects. Twenty-seven subjects received gemigliptin (50 mg once daily), metformin (1,000 mg twice a day), or both drugs for 7 days per dosing period. Blood samples were drawn over 24 h on the seventh day of each period for pharmacokinetic and pharmacodynamic evaluations, including plasma DPP-4 activity and total/active glucagon-like peptide-1 (GLP-1) levels. Meal tolerance tests were conducted for pharmacodynamic assessment on the eighth day. Safety and tolerability were evaluated using adverse events, vital signs, ECGs, and clinical laboratory tests. Results: Coadministration of gemigliptin and metformin had no significant effect on the pharmacokinetics of gemigliptin or metformin. The inhibition of DPP-4 by gemigliptin was not affected by coadministration with metformin. Co-therapy of gemigliptin and metformin showed additional effects by increasing plasma active GLP-1 concentrations and lowering serum glucose levels. The plasma glucagon level was lower in co-therapy than with metformin monotherapy. The coadministration of gemigliptin and metformin was well-tolerated without serious adverse events. Conclusions: Coadministration of gemigliptin and metformin showed beneficial anti-diabetic effects without pharmacokinetic drug-drug interactions. [ABSTRACT FROM AUTHOR]

There is an increasing need for more sensitive analytical methods in pharmacokinetic studies, for example, for phase 0 clinical trials. A novel HPLC Chip–triple quadrupole mass spectrometer method (HPLC Chip-MS/MS method) for the quantification of 7-ethyl-10-hydroxycamptothecin (SN38) was developed, validated, and employed to the pharmacokinetic analysis of SN38 in ICR mice. Protein precipitation with a ratio of plasma/acetonitrile of 1:10 was chosen as the sample processing method. The nano-electrospray inserted in the microfluidic chip operated in positive mode, and selected reaction monitoring was used for quantification. Our bioanalytical method met all essential validation parameters—selectivity, accuracy, precision, dilution integrity, calibration curve, matrix effect, recovery, and different stability tests (benchtop, freeze–thaw, autosampler stability). The calibration curves (weight 1/ x2) were linear for the range 50–10,000 pg/mL. Clogging was not observed until the end of the lifetime of the microfluidic chip (350–400 injections), and carryover was practically eliminated through the introduction of a step gradient elution program. After intraperitoneal injection of 0.1 mg/kg irinotecan, SN38 concentration could be measured up to 6 h with accuracy and precision. Thus, we developed a new, very sensitive HPLC Chip-MS/MS method for the determination of plasma SN38 that has been validated in compliance with guidelines from different regulation authorities. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Background: DA-3031 is a newly developed pegylated filgrastim, a recombinant human granulocyte colony-stimulating factor, that is expected to have an extended duration of action compared with non-modified filgrastim. Objective: This study evaluated the tolerability, pharmacokinetics, and pharmacodynamics of DA-3031 in humans, and compared them with filgrastim. Methods: The study was conducted in 48 healthy male Korean subjects. Forty subjects received subcutaneous single doses of 1.8, 3.6, 6, or 18 mg of DA-3031 or placebo in a dose block-randomized, double-blind, dose-escalation design. The remaining eight subjects were given subcutaneous doses of 100 μg/m of filgrastim daily for 5 days. Serial blood samples were collected for pharmacokinetic and pharmacodynamic analyses up to 312 h after the administration of DA-3031 and up to 264 h following the first administration of filgrastim. Results: DA-3031 reached its peak plasma concentration at 6.0-48.0 h and was eliminated mono-exponentially. The pharmacokinetic parameters of DA-3031 increased with dose in a non-linear fashion. Absolute neutrophil count (ANC) levels increased with the dose of DA-3031, although the extent of the increase in ANC decreased at higher dose levels. DA-3031 resulted in similar ANC changes in the 3.6 to 6 mg dose range as 100 μg/m of filgrastim. The most frequent adverse event was back pain, which was observed after both DA-3031 and filgrastim administration. Conclusions: DA-3031 showed non-linear pharmacodynamic and pharmacokinetic profiles and an extended duration of action compared with non-modified filgrastim, without unexpected toxicities in healthy subjects. [ABSTRACT FROM AUTHOR]

Objectives:Zabofloxacin is being developed as a new fluoroquinolone antibiotic that is a potent and selective inhibitor of the essential bacterial type II topoisomerases and topoisomerase IV. Zabofloxacin is indicated for community-acquired respiratory infections due to Gram-positive bacteria. The aim of this study was to compare the pharmacokinetics (PK) of the zabofloxacin hydrochloride 400 mg capsule (DW224a, 366.7 mg as zabofloxacin) with the PK of the zabofloxacin aspartate 488 mg tablet (DW224aa, 366.5 mg as zabofloxacin) in healthy Korean male volunteers to assess the bioequivalence between the two drug formulations. Methods:A randomized, open-label, single-dose, two-way crossover study was performed. The subjects received either DW224a or DW224aa according to their sequence group. Plasma concentrations of zabofloxacin were determined by liquid chromatography–tandem mass spectrometry. The maximum plasma concentrations (Cmax), the area under the plasma concentration versus time curve (AUC) from the time of dosing to 48 hours post-dosing (AUClast), and the AUC extrapolated to infinity (AUCinf) were determined from the plasma concentration–time profile. (ClinicalTrials.gov identifier: NCT01341249). Results:Twenty-nine of the 32 subjects enrolled completed the study. The Cmax, AUClast, and AUCinf (mean SD) values of DW224a were 1889.7493.4 ng/mL, 11,1102005.0 ng*h/mL, and 11,2872012.6 ng*h/ mL, respectively, and those of DW224aa were 2005.0341.3 ng/mL, 11,7192507.5 ng*h/mL, and 11,9132544.8 ng*h/mL, respectively. The geometric mean ratios (90% confidence intervals) of the Cmax, AUClast, and AUCinf were 1.08 (1.00–1.17), 1.05 (1.00–1.10), and 1.05 (1.00–1.10), respectively, and were within the bioequivalence acceptance range of 0.8–1.25. Both drugs were well tolerated with no serious adverse events. Conclusion:A single oral dose of DW224a or DW224aa to healthy volunteers appeared to be well tolerated. Both DW224a and DW224aa exhibited comparable PK profiles and were bioequivalent in terms of PK parameters. Further studies in patients are needed to corroborate the result of this study. [ABSTRACT FROM AUTHOR]

Pharmacokinetic/pharmacodynamic ( PK/ PD) models can be useful tools in new drug development and also optimal drug therapy in patients. This study was designed to develop a PK/ PD model of sitagliptin based on the physiology of incretin. The PK/ PD data included information derived from two different studies. Study 1 was conducted as a one-sequence, three-period, repeated-dose, dose escalation (sitagliptin 25, 50 and 100 mg q.d.) design in twelve healthy volunteers. Study 2 was a first-in-man study for the newly developed dipeptidyl peptidase-4 ( DPP-4) inhibitor in healthy volunteers. In study 1, blood samples were collected to measure sitagliptin concentrations, DPP-4 activity and active glucagon-like peptide-1 ( GLP-1) concentrations. In study 2, only data from the 'placebo group' were used, and blood samples were collected to measure DPP-4 activity, active GLP-1 concentrations and glucose concentrations. A PK/ PD analysis was conducted using a non-linear mixed effects modelling approach. Sitagliptin pharmacokinetics was modelled using a two-compartment model with first-order absorption. Changes in DPP-4 inhibition were linked to the PK model using a sigmoid Emax model, whereas the active GLP-1 changes were explained using an indirect response model; this model incorporated the glucose and DPP-4 inhibition models. The PK/ PD model developed adequately described the changes in sitagliptin concentration, DPP-4 inhibition and active GLP-1 concentration in healthy volunteers. [ABSTRACT FROM AUTHOR]

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Atenolol is an antihypertensive drug, of which negligible amounts are metabolized. • Fruit juices may decrease the oral absorption of drugs by inhibiting intestinal drug transporters, as demonstrated in vitro and in vivo. WHAT THIS STUDY ADDS • The pharmacokinetic characteristics of atenolol were determined according to the SLCO2B1 genotype after apple juice administration in healthy Korean volunteers. • Apple juice ingestion markedly reduced the systemic exposure to atenolol, but genetic variations in SLCO2B1 were unlikely to contribute substantial variability to the pharmacokinetics of atenolol. AIM Fruit juice reduces the plasma concentrations of several β-adrenoceptor blockers, likely by inhibiting OATP2B1-mediated intestinal absorption. The aim of this study was to investigate the effects of apple juice on the pharmacokinetics of atenolol. METHODS Twelve healthy Korean volunteers with genotypes of SLCO2B1 c.1457C> T (* 1/* 1 ( n= 6) and * 3/* 3 ( n= 6)) were enrolled in this study. In a three-phase, one-sequence crossover study, the pharmacokinetics (PK) of atenolol was evaluated after administration of 50 mg atenolol. Subjects received atenolol with either 300 ml water, 1200 ml apple juice or 600 ml apple juice. RESULTS Apple juice markedly reduced the systemic exposure to atenolol. The geometric mean ratios (95% confidence intervals) of apple juice : water were 0.18 (0.13, 0.25, 1200 ml) and 0.42 (0.30, 0.59, 600 ml) for the AUC(0, tlast). In this study, the PK parameters of atenolol responded in a dose-dependent manner to apple juice. CONCLUSIONS Apple juice markedly reduced systemic exposure to atenolol. The genetic variation of SLCO2B1 c.1457C>T had a minimal effect on the pharmacokinetics of atenolol when the drug was administered with water or apple juice. [ABSTRACT FROM AUTHOR]

The current study assessed the influence of the CYP2C19 genotype on the pharmacokinetics and tolerability of voriconazole after single and multiple oral doses in healthy volunteers. Six subjects for the CYP2C19 homozygous extensive metabolizer (EMs), 6 for heterozygous extensive metabolizer (HEMs), and 6 for poor metabolizer (PMs) were enrolled, and their CYP2C9, CYP3A5, and MDR1 genotypes were analyzed. After a single intravenous infusion or single and multiple oral doses of 200 mg of voriconazole, plasma concentrations of voriconazole were measured. Bioavailability was not significantly different among the CYP2C19 genotypes. Voriconazole exposure in PMs was approximately 3 times higher compared with EMs after a single intravenous or oral dose. At steady state, the plasma concentration just before the next dosing and area under the concentration-time curve from dosing to the time point of the next dosing for PMs were about 5 times and 3 times higher than EMs, respectively. These results suggest that the CYP2C19 genotype is the major determinant of the wide PK variability of voriconazole. [ABSTRACT FROM PUBLISHER]

Summary The rapid achievement of effective levels of antiepileptic drugs (AEDs) is required in patients with epilepsy who have a higher risk of seizures, and oral loading of AEDs may be an important consideration in these patients. We performed the present study to investigate the efficacy and tolerability of oral loading of oxcarbazepine in patients with recurrent seizures, or after temporary discontinuation of AEDs for diagnostic or presurgical evaluation of epilepsy. Forty adult patients were studied and oxcarbazepine was administered orally at a single loading dosage of 30 mg/kg. The plasma levels of oxcarbazepine and its active metabolite, 10,11-dihydro-10-hydroxy-carbazepine (monohydroxy derivative, MHD), were measured, and clinical assessment of adverse events was performed at 2, 4, 6, 8, 10, 12, 16, and 24 h after oral loading of oxcarbazepine. Approximately two-thirds of patients reached effective levels of MHD 2 h after receiving the oral loading, and all patients reached effective levels 4 h after oxcarbazepine administration. Most patients maintained therapeutic MHD levels for at least 16 h. Almost half of the patients experienced adverse events, but all were mild to moderate in severity and resolved spontaneously within 24 h. Our study shows that oral loading of oxcarbazepine is an effective and well-tolerated method for rapidly achieving therapeutic levels of MHD in patients with epilepsy, and is a useful option in selected patients with recurrent seizures, or after temporary discontinuation of AEDs. [ABSTRACT FROM AUTHOR]

Background: Pitavastatin is a potent, newly developed 3-hydroxy-3-methylglutaryl–coenzyme A reductase inhibitor for the treatment of hyperlipidemia. We characterized the effects of organic anion transporting polypeptide 1B1 (OATP1B1) alleles *1a, *1b, and *15 on the pharmacokinetics of pitavastatin. Methods: Twenty-four healthy Korean volunteers who had previously participated in a pharmacokinetic study of pitavastatin (single oral dose, 1-8 mg) were further investigated. Subjects were grouped according to OATP1B1 genotype. Dose-normalized area under the plasma concentration–time curve (AUC) and peak plasma concentration (Cmax) values were analyzed, because different dosages were administered to subjects, whereas the pharmacokinetics showed linear characteristics. Results: Dose-normalized pitavastatin AUCs for *1b/*1b (group 1), *1a/*1a or *1a/*1b (group 2), and *1a/*15 or *1b/*15 (group 3) were 38.8 ± 13.3, 54.4 ± 12.4, and 68.1 ± 16.3 ng·h·mL−1 ·mg−1 (mean ± SD), respectively, with significant differences between all 3 groups (P = .008) and between subjects carrying and those not carrying the *15 allele (P = .004). Dose-normalized pitavastatin Cmax values were 13.2 ± 3.3, 18.2 ± 5.7, and 29.4 ± 9.6 ng·mL−1 ·mg−1 in groups 1, 2, and 3, respectively, and also showed significant differences (P = .003) in a manner similar to that shown by AUC. No significant differences were found between the genotype groups in terms of dose-normalized AUC or Cmax values of pitavastatin lactone. Conclusion: OATP1B1 variant haplotypes were found to have a significant effect on the pharmacokinetics of pitavastatin. These results suggest that the *15 allele is associated with decreased pitavastatin uptake from blood into hepatocytes and that OATP1B1 genetic polymorphisms have no effect on the pharmacokinetics of pitavastatin lactone. [Copyright &y& Elsevier]

Objective: Our objective was to investigate the effect of the uridine 5′-diphosphate-glucuronosyltransferase (UGT) 2B15 genetic polymorphism on the pharmacokinetics and pharmacodynamics of lorazepam in basal, inhibited, and induced metabolic states in healthy normal volunteers. Methods: Twenty-four healthy subjects were enrolled and grouped into UGT2B15*1/*1 or UGT2B15*2/*2 genotype groups. The pharmacokinetic and pharmacodynamic profiles of intravenous lorazepam were characterized before and after inhibition with 600 mg valproate once daily for 4 days and after induction with rifampin (INN, rifampicin) pretreatment (600 mg once daily for 10 days), with a washout period of 10 days between. The plasma concentrations of lorazepam and lorazepam glucuronide were analyzed before and at 0.25, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours after lorazepam administration by liquid chromatography-tandem mass spectrometry. Visual analog scale assessments and psychomotor coordination tests were administered before and up to 12 hours after drug administration. Results: The UGT2B15*2/*2 group showed 0.58-fold (95% confidence interval, 0.43–0.72; P <.0001) lower systemic clearance during the basal state and 1.37-fold (95% confidence interval, 1.05–1.88; P = .037) higher area under the visual analog scale-time curve during the induced state compared with the UGT2B15*1/*1 group. The mean systemic clearance of lorazepam decreased by 20% in the inhibited state and increased by 140% in the induced state. During the inhibited or induced state, absolute values of clearance were consistently lower in the *2/*2 group, but the percent changes from baseline did not differ significantly by genotype. Conclusions: Our results suggest that the UGT2B15*2 polymorphism is a major determinant of interindividual variability with respect to the pharmacokinetics and pharmacodynamics of lorazepam. [Copyright &y& Elsevier]

Amikacin is used as a therapy for patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) who are resistant to macrolide antibiotics or have severe symptoms. This study aimed to characterize the pharmacokinetic properties of amikacin in patients with NTM-PD by developing a population pharmacokinetic model and to explore the optimal pharmacotherapy in patients with NTM-PD. For this study, all data were retrospectively collected. The amikacin pharmacokinetic properties were best described by a two-compartment model with first-order elimination. The estimated glomerular filtration rate and body weight were identified as significant covariates for clearance and the volume of distribution, respectively. A model-based simulation was conducted to explore the probability of reaching the target therapeutic range when various dose regimens were administered according to the body weight and renal function. The simulation results indicated that the amikacin dosage should be determined based on the body weight, and for patients who weigh over 70 kg, it is necessary to adjust the dose according to renal function. In conclusion, the optimal pharmacotherapy of amikacin for patients with NTM-PD was recommended based on the population pharmacokinetic model, which is expected to enable the personalization of drug therapy and improve the clinical outcomes of amikacin therapy. [ABSTRACT FROM AUTHOR]

Dexmedetomidine is a selective alpha-2 adrenergic agonist with concurrent sedative and analgesic effects, and it is being increasingly used in pediatric anesthesia and intensive care. This study aimed to investigate the pharmacokinetics of intravenous dexmedetomidine in mechanically ventilated children in the intensive care unit (ICU) after neurosurgery. Pediatric patients aged 2–12 years, who were mechanically ventilated in ICU after neurosurgery, were allocated into a low-dose (n = 15) or high-dose (n = 14) group. The low-dose group received dexmedetomidine at a loading dose of 0.25 µg/kg for 10 min, followed by a maintenance dose of 0.25 µg/kg/h for 50 min, whereas the high-dose group received dexmedetomidine at a loading dose of 0.5 µg/kg for 10 min, followed by a maintenance dose of 0.5 µg/kg/h for 50 min. Serial blood samples were collected for a pharmacokinetic analysis up to 480 min after the end of the infusion. The sedative effect of dexmedetomidine was assessed using the Bispectral Index and University of Michigan Sedation Scale. Adverse reactions, electrocardiography findings, and vital signs were monitored for a safety assessment. A population pharmacokinetic analysis was performed using non-linear mixed effects modeling. Dexmedetomidine induced a moderate-to-deep degree of sedation during infusion in both groups. The pharmacokinetics of dexmedetomidine were best described by a two-compartment disposition model with first-order elimination kinetics. The parameters were standardized for a body weight of 70 kg using an allometric power model. The population estimates (95% confidence interval) per 70 kg body weight were as follows: clearance of 81.0 (72.9–90.9) L/h, central volume of distribution of 64.2 (50.6–81.0) L, intercompartment clearance of 116.4 (90.6–156.0) L/h, and peripheral volume of distribution of 167 (132–217) L. No serious adverse reactions or hemodynamic changes requiring the discontinuation of dexmedetomidine were observed. Dexmedetomidine had increased clearance and volume of distribution in mechanically ventilated children in ICU after neurosurgery, thereby indicating the need to adjust the dosage to obtain a target plasma concentration. [ABSTRACT FROM AUTHOR]

Evogliptin is a novel potent and selective dipeptidyl peptidase-4 ( DPP-4) inhibitor. The aim of the present study was to evaluate the pharmacokinetic ( PK) and pharmacodynamic ( PD) characteristics of evogliptin in participants with renal impairment ( RI). An open-label, parallel-group clinical study was conducted in participants with mild, moderate and severe RI and in matched participants with normal renal function ( NRF). A single oral 5-mg dose of evogliptin was administered and serial blood and urine samples were obtained to assess the PK and PD characteristics of evogliptin. Baseline urine samples were collected to evaluate endogenous CYP3A metabolic markers. The plasma exposure to evogliptin and degree of DPP-4 activity inhibition increased with decreasing renal function. The mean areas under the concentration-time curves from 0 to 120 hours were increased 1.2-, 1.8- and 1.98-fold in the mild, moderate and severe RI groups, respectively, compared with the NRF group. The levels of CYP3A metabolic markers were lower in the RI group than in the NRF group. The increase in the plasma concentration of evogliptin is unlikely to result in changes in its efficacy or safety, considering the results of previous clinical studies. [ABSTRACT FROM AUTHOR]

Human multidrug and toxin extrusion member 2 (MATE2-K, SLC47A2) plays an important role in the renal elimination of various clinical drugs including the antidiabetic drug metformin. The goal of this study was to characterize genetic variants of MATE2-K and determine their association with the pharmacokinetics of metformin.We screened DNA samples from 48 healthy Koreans for variants in the promoter and coding regions of MATE2-K and examined the function of common haplotypes in the promoter region using in-vitro luciferase assays. Then, the metformin pharmacokinetic study was carried out to determine the association between MATE2-K promoter haplotypes and metformin pharmacokinetics.Nine variants in the promoter region of MATE2-K and one nonsynonymous variant, p.G211V, were identified. The MATE2-K promoter haplotype 1 containing a known functional polymorphism, g.-130G>A and haplotype 2 containing two polymorphisms, g.-609G>A and g.-396G>A showed a significant increase in reporter activity. Among the 45 individuals who participated in the metformin pharmacokinetic study, 12 healthy Koreans who were homozygous for haplotype 1 or 2 showed a significant increase in renal clearance [539±76 (reference group) vs. 633±102 (variant group) ml/min; P=0.006] and secretion clearance [439±81 (reference group) vs. 531±102 (variant group) ml/min; P=0.007] of metformin compared with that shown by the reference group.Our study suggests that common promoter haplotypes of MATE2-K are associated with the pharmacokinetics of metformin. [ABSTRACT FROM AUTHOR]

Abstract: Background: Inhibitors of dipeptidyl peptidase (DPP) IV are a class of oral hypoglycemic agents that increase glucagon-like peptide-1 (GLP-1) levels by inhibiting its degradation. Objective: This study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of DA-1229, which is a newly developed DPP IV inhibitor. This study was planned as part of a product development project at the request of the Korean regulatory agency. Methods: A 7 parallel arm dose-escalation study was conducted in healthy Korean male volunteers. A single oral dose of DA-1229 or placebo was given to 10 subjects (8 active + 2 placebo) in each dose group of 1.25, 2.5, 5, 10, 20, 40, or 60 mg. To assess the effects of food, the subjects in the 10-mg dose group received a single dose of DA-1229 10 mg after a high-fat meal, crossing over from the administration of DA-1229 under a fasting state, after a 7-day washout period. Serial blood samples were collected up to 120 hours after drug administration for pharmacokinetic analysis and the assessment of DPP IV activity, and blood samples were collected up to 2 hours after each meal until the next morning of drug administration to evaluate active GLP-1, glucose, and insulin levels. Results: Seventy-two subjects, aged 20 to 39 years and weighing 52.1 to 79.8 kg, participated in this study. Twenty-one adverse events were reported; all were mild, and all subjects recovered spontaneously. DA-1229 reached a peak at 3.0 to 5.5 hours after a single oral dose and the concentrations declined, with a terminal t½ from 32.5 to 39.8 hours. The %CV of Cmax and AUC0–last ranged from 11.1% to 54.6%. Dose-proportional pharmacokinetics were confirmed within the dose range by using a linear regression analysis, and the 95% CIs of the slope of the log-transformed Cmax and AUC0–last included 1.0. The pharmacokinetics of DA-1229 were unchanged by food. The degree of DPP IV inhibition was dependent on the dose, and groups receiving ≥10 mg exhibited >80% DPP IV inhibition for >24 hours. The %CV of the time of the last quantifiable concentration ranged from 4.6% to 15.2%. Cmax of active GLP-1 was achieved at 30 minutes after meal intake. The active GLP-1 levels were enhanced in groups receiving ≥5 mg. There were no changes in the glucose and insulin levels after DA-1229 administration. Conclusions: DA-1229 was well tolerated within the dose range of 1.25 to 60 mg. DA-1229 pharmacokinetics suggested dose proportionality, and dose-dependent DPP IV inhibition was exhibited. ClinicalTrials.gov identifier: NCT00961025. [Copyright &y& Elsevier]

Abstract: Background: Fimasartan is an angiotensin II receptor antagonist used to treat hypertension. Objective: The aim of this study was to evaluate the effects of fimasartan on the pharmacodynamics and pharmacokinetics of warfarin in healthy volunteers to meet regulatory requirements for drug marketing and labeling in Korea. Methods: An open-label, 1-sequence, 2-treatment, 2-period crossover study was conducted in healthy male volunteers. The subjects were administered a single-dose of warfarin 25 mg on day 1. After a 7-day washout period, once-daily fimasartan 240 mg was administered every morning from day 8 to day 16. On day 11, warfarin 25 mg was administered concomitantly with fimasartan. Serial blood samples were collected for 144 hours after each warfarin dose. The plasma concentrations of R- and S-warfarin were analyzed by using HPLC-MS/MS, and the pharmacokinetic parameters were estimated by using noncompartmental analysis. The maximal international normalized ratio (INR) and the AUC–INR curve were evaluated to assess warfarin pharmacodynamics. Tolerability was assessed via vital sign measurements, physical examinations, ECGs, clinical laboratory tests, and adverse events. Results: A total of 15 healthy Korean men aged 20 to 39 years (mean [SD], 26.7 [5.1] years) and weighing 60.2 to 85.7 kg (mean, 71.4 [8.3] kg) participated in the study; 12 completed the study. The geometric mean ratios (GMRs [90% CIs]) of Cmax and AUC0–last for R-warfarin were 1.06 (0.97–1.16) and 1.07 (1.03–1.12), respectively. For S-warfarin, the GMRs (90% CIs) of Cmax and AUC0–last were 1.02 (0.94–1.11) and 0.99 (0.94–1.04). The INR values reached 1.93 (0.31) and 1.96 (0.37) at 36 hours and decreased to <1.2 at 144 hours after warfarin treatment alone and coadministered with fimasartan, respectively. The GMRs (90% CIs) of the maximal INR and AUC–INR curve were 1.01 (0.97–1.05) and 0.98 (0.96–1.01). One (7.7%) of the 13 subjects reported epistaxis during treatment with warfarin alone, and 2 (16.7%) of 12 subjects receiving the combination treatment experienced headache, skin erosion, and an increase in blood creatine phosphokinase. No subjects had an elevated INR >4 or reported any symptoms related to hypotension, including fainting or dizziness. Conclusion: Multiple doses of fimasartan did not seem to alter the pharmacodynamics or pharmacokinetics of warfarin in this small, select population of healthy male volunteers. ClinicalTrials.gov identifier: NCT00923533. [Copyright &y& Elsevier]

Abstract: Background: The combination of glimepiride and metformin is used for glycemic control in patients with diabetes mellitus. A fixed-dose combination of glimepiride/metformin 2/500 mg slow-release (SR) formulation was developed to improve compliance in polymedicated patients. To accommodate the various dosing regimens of glimepiride, a glimepiride/metformin 1/500 mg SR tablet was also developed. Objective: The goal of this study was to compare the pharmacokinetic properties of SR fixed-dose combinations of glimepiride/metformin 2/500 mg and the newly developed glimepiride/metformin 1/500 mg formulation to meet the regulatory requirements for marketing in Korea. Methods: An open-label, randomized, 2-treatment, 2-period, 2-sequence crossover study was conducted with healthy male volunteers. Eligible subjects were randomly assigned to receive a single dose of glimepiride/metformin 1/500 mg SR (test) or glimepiride/metformin 2/500 mg SR (reference) followed by a 1-week washout period and then administration of the alternate treatment. Serial blood samples were collected immediately before and after dosing for 30 hours, and plasma concentrations were determined by using LC-MS/MS with validated methods. Adverse events were assessed by subjects'' self-report and interviews addressing general health-related issues. Safety profiles were evaluated throughout the study. Results: Thirty-three subjects were enrolled (mean [SD] age: 27.9 [4.95] years [range, 21–40 years]). Safety profiles were assessed for all 32 subjects who were administered the study drugs, and pharmacokinetic characteristics were evaluated in the 30 subjects who completed the study. The geometric mean ratios (90% CIs) of test to reference for the dose-normalized Cmax and AUC0–last of glimepiride were 0.98 (0.90–1.07) and 1.06 (0.98–1.14), respectively. In the case of metformin, the geometric mean ratios (90% CIs) of test to reference for Cmax and AUC0–last were 1.06 (0.98–1.15) and 1.04 (0.97–1.12), respectively. Nine adverse events were reported. Among them, loose stool, abdominal pain, and headache were considered to be likely related to the study drug. All reported adverse events were mild in intensity. Conclusions: Dose-proportional characteristics of glimepiride and comparable pharmacokinetic properties of metformin were observed between the SR fixed-dose combinations of glimepiride/metformin 1/500 mg and 2/500 mg. A single dose of either treatment was well tolerated, and the safety profiles of the 2 treatments were comparable in this small, selected all-male group of healthy Korean volunteers. ClinicalTrials.gov identifier: NCT00934323. [Copyright &y& Elsevier]

Abstract: Background: Lobeglitazone, a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist with partial PPAR-α affinity, was developed to treat type 2 diabetes mellitus. Objective: This study''s aim was to evaluate the tolerability and pharmacokinetic (PK) properties of lobeglitazone to satisfy regulatory requirements for marketing approval in Korea. Methods: A block-randomized, double-blind, placebo-controlled, single- and multiple-dose study was conducted in healthy subjects. In the pilot study, 4 subjects were administered 0.5 mg, including 1 receiving a placebo. Then, the single-dose study was conducted with 1, 2, 4, and 8 mg doses (8 subjects in each group, including 2 receiving placebos), followed by the multiple-dose study with 1, 2, and 4 mg doses (once daily for 7 days; 8 subjects in each group, including 2 receiving placebos). Serial samples of blood and urine were collected and drug concentrations were determined by high turbulence liquid chromatography-LC/MS/MS. Tolerability assessments were performed throughout the study. Adverse events (AEs) were determined from general health-related questions and self-reports. Results: Thirty-six (mean [SD]; age, 23.6 [2.7] years; weight, 70.0 [6.9] kg) and 25 Korean male subjects (age, 23.5 [3.1] years; weight 69.4 [9.4] kg) were enrolled in the single- and multiple-dose studies, respectively. The data from subjects administered lobeglitazone who completed the study (27, single; 18, multiple) was included in the PK analyses. In the single-dose study, the AUC and Cmax of lobeglitazone increased with the dose. After repeated dosing for 7 days, the accumulation ratio ranged from 1.1 to 1.4. A total of 25 AEs were reported by 11 (30.6%) and 8 subjects (33.3%) in the single- and multiple-dose studies, respectively. All AEs were mild in intensity and not serious. Conclusions: Lobeglitazone was well tolerated in this small, selected group of healthy male Korean volunteers. The AUC and Cmax of lobeglitazone increased in a dose-proportional manner from 1 to 4 mg. [Copyright &y& Elsevier]

Abstract: Background: A fixed-dose combination tablet of tramadol/acetaminophen exhibits both rapid and sustained analgesic effects due to different pharmacologic activities. To prolong analgesia and improve patient convenience, an extended-release (ER) tablet of this agent has been developed. Objective: The aim of this study was to explore the pharmacokinetic profiles of the new ER tramadol/acetaminophen fixed-dose combination and compare them with those of a conventional immediate-release (IR) formulation after multiple dosing as a Phase I clinical exploratory trial. Methods: An open-label, randomized, 2-sequence crossover study was conducted in healthy volunteers. All subjects received both formulations for 4 days: either 1 IR tablet (tramadol 37.5 mg/acetaminophen 325 mg) q6h followed by 1 ER tablet (tramadol 75 mg/acetaminophen 650 mg) q12h, or vice versa. A 5-day washout period separated the 2 treatments. Tramadol and acetaminophen concentrations in plasma were determined simultaneously using LC-MS/MS, and the pharmacokinetic properties were analyzed by noncompartmental method. To compare the systemic exposure of the 2 formulations, the geometric mean ratios (GMRs) for AUC0–12,ss and the 90% CIs were calculated. Adverse events (AEs) were identified through subject interviews, recording of vital signs, physical examinations, 12-lead electrocardiography, and clinical laboratory assessments. Results: Twelve healthy, nonsmoking, Korean male subjects completed the study. The mean (SD) age was 24.4 (5.2) years and the mean body weight was 65.1 (6.0) kg. The Tmax,ss for tramadol was delayed until 3 hours after the ER treatment, compared with 1 hour after the IR treatment, whereas the Tmax,ss of acetaminophen was 30 minutes after each treatment. The mean (SD) of AUC0–12,ss in the IR and ER formulations was 2789.0 (507.7) and 2638.7 (469.1) µg/h/L for tramadol and 42,635.0 (8711.2) and 40,394.3 (10,127.7) µg/h/L for acetaminophen, respectively. The GMR of ER to IR for AUC0–12,ss was 0.95 (90% CI, 0.91–0.99) for tramadol and 0.94 (90% CI, 0.89–0.99) for acetaminophen. A total of 17 AEs occurred in 9 subjects; all AEs were considered mild or moderate and resolved without medical intervention. The most frequent AEs were headache and dizziness (3 cases each). Conclusions: The ER formulation displayed a similar AUC0–12,ss to that of the IR formulation for tramadol and acetaminophen. [Copyright &y& Elsevier]

Objective: This study compared the bioavailability and tolerability of a fixed-dose combination (FDC) tablet of glimepiride/metformin 2/500 mg and glimepiride 2-mg + metformin 500-mg tablets administered separately in healthy Korean subjects. Methods: In this single-dose, open-label, 2-period crossover study, healthy Korean volunteers were randomly assigned to receive, in 1 of 2 randomized sequences, an FDC tablet of glimepiride/metformin 2/500 mg (test) and glimepiride 2-mg + metformin 500-mg tablets administered separately (reference), with a 1-week washout period between treatments. Plasma concentrations of glimepiride and metformin were measured using LC/MS-MS. Pharmacokinetic parameters were analyzed using noncompartmental methods. Bioequivalence was concluded if the 90% CIs of the geometric mean test/reference ratios (GMRs) of the logarithm-transformed Cmax, AUC from 0 to 30 hours (AUC0–30), and AUC0−∞ values were within the predetermined regulatory range of 80% to 125%. Tolerability was assessed using physical examination and laboratory analysis. Results: A total of 32 subjects were enrolled (16 men [mean (SD) age, 21.8 (2.7) years (range, 18–26 years); weight, 68.9 (8.3) kg (range, 55.5–85.0 kg)]; 16 women [age, 23.5 (4.5) years (range, 20–38 years); weight, 51.7 (3.5) kg (range, 46.8–58.0 kg)]). The GMRs (90% CI) of glimepiride Cmax, AUC0–30, and AUC0−∞ were 1.01 (0.91–1.11), 0.98 (0.92–1.03), and 0.97 (0.93–1.04), respectively. For metformin, these values were 0.96 (0.87–1.06), 0.96 (0.90–1.03), and 0.96 (0.90–1.03). A total of 49 adverse events (AEs) were reported in 10 subjects (31.3%) with the FDC and in 13 subjects (40.6%) with the separate tablets. The most commonly reported AEs with the test and reference treatments were dizziness (6 [19%] and 7 [22%]) and sweating (4 [13%] and 7 [22%]), respectively. The severity of all of the AEs was considered to be mild, and there were no significant differences in the prevalences of AEs between the 2 formulations. Conclusions: In this study in healthy Korean subjects, the requirements for bioequivalence of the glimepiride/metformin 2/500-mg FDC and coadministration of separate tablets of each drug were met. Both formulations were generally well tolerated. [Copyright &y& Elsevier]

Background: Flecainide acetate is a class Ic antiarrythmic agent that is metabolized by the cytochrome P450 (CYP) 2D6 isozyme. A previous open-label, 2-period, single-sequence crossover study in healthy Korean male volunteers found differences in the pharmacokinetics of flecainide between subjects with the CYP2D6 wild-type allele and those with the CYP2D6*10 allele, as well as differences in the pharmacokinetic interaction between flecainide and the CYP2D6 inhibitor paroxetine between genotype groups. Objective: This study evaluated QTc-interval changes after administration of a single oral dose of flecainide, with and without paroxetine, in relation to CYP2D6 genetic polymorphism. Methods: This was a follow-on to the previous pharmacokinetic study and used data from the same group of healthy Korean male volunteers. Subjects were grouped by CYP2D6 genotype as follows: CYP2D6*1/*1 or CYP2D6*1/*2 (group 1, extensive metabolizers); CYP2D6*1/*10 (group 2, intermediate metabolizers); and CYP2D6*10/*010 or CYP2D6*10/*36 (group 3, poor metabolizers). Flecainide 200 mg was administered on day 1 (period 1); after a 7-day washout period, subjects received paroxetine 20 mg once daily from day 8 to day 14, and flecainide 200 mg on day 15 (period 2). On days 1 and 15, serial 12-lead ECGs were obtained before flecainide dosing and at 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, and 24 hours after dosing. Baseline ECGs were obtained at the same time points on days -1 and 14. Machine-read changes in the QT interval corrected using the Fridericia formula (QTcF) and manually read changes in the QT interval individually corrected using mixed-effects modeling (QTcI) from time-matched baseline were analyzed by genotype and by period (baseline and paroxetine-inhibited state). The QRS duration and JTc interval (QTcF - QRS) were also determined. Results: Twenty-one healthy volunteers (mean [SD] age, 24.5 [3.0] years; mean height, 173.5 [4.6] cm; mean weight, 69.1 [4.5] kg), 7 in each group, were enrolled in and completed the study. In period 1, all genotype groups had significant increases from time-matched baseline in both the QTcF interval (group 1:17.4 milliseconds [90% CI, 9.9-24.9], P < 0.001; group 2: 11.1 milliseconds [90% CI, 7.9-14.3], P = 0.013; and group 3: 20.5 milliseconds [90% CI, 12.8-28.2], P < 0.001) and the QTcI interval (group 1:15.4 milliseconds [90 % CI, 8.0-22.9], P = 0.001; group 2: 9.1 milliseconds [90% CI, 6.5-11.8], P = 0.030; and group 3:16.4 milliseconds [90% CI, 9.3-23.5], P = 0.001); the extent of increase did not differ significantly between groups. In groups 1 and 2, the least squares mean difference between period 1 and period 2 was statistically significant for the change in QTcF interval (6.5 milliseconds [90 CI, 3.2-9.8], P = 0.002; and 6.7 milliseconds [90% CI, 3.6-9.7], P = 0.001, respectively) and QTcI interval (6.9 milliseconds [90% CI, 4.1-9.8], P < 0.001; and 5.8 milliseconds [90% CI, 3.4-8.3], P < 0.001). In group 3, the least squares mean difference between period 1 and period 2 was statistically significant for the change in QTcI interval (3.9 milliseconds [90% CI, 1.3-6.5], P = 0.015) but not for the change in QT cF interval. The changes in QRS duration did not differ significantly by genotype or period. Consistent with the findings for the QTc interval, the least squares mean difference between period 1 and period 2 was statistically significant for the change in JTc interval in groups 1 and 2 (6.9 milliseconds [90% CI, 3.7-10.2], P = 0.001; and 5.4 milliseconds [90% CI, 2.7-8.2], P = 0.001, respectively) but not in group 3. Conclusion: The extent of drug interaction between flecainide and paroxetine, as reflected in the change in QTc interval (used as a pharmacodynamic biomarker), was influenced by the CYP2D6*10 allele in these healthy Korean male volunteers. [Copyright &y& Elsevier]

Background: Ginkgo biloba extract is an herbal medicine used in the treatment of vascular disorders that may be coadministered with antiplatelet agents such as ticlopidine. Regulatory authorities requested evaluation of the pharmacodynamic and pharmacokinetic interactions between these entities, according to the drug-development guidance for fixed-dose combination formulations in Korea. Objective: This study was performed to evaluate the potential pharmacodynamic and pharmacokinetic interactions between ticlopidine and Ginkgo biloba extract. Methods: An open-label, randomized, 2-period, 2-treatment, 2-sequence, single-dose crossover study was conducted in healthy Korean male volunteers. All volunteers were randomly assigned to a sequence group for the 2 treatments, which consisted of ticlopidine 250 mg alone and ticlopidine 250 mg with Ginkgo biloba extract 80 mg, separated by a 1-week washout period between the treatments. Bleeding time was determined just before dosing and at 5, 12, and 48 hours after dosing. Platelet aggregation was evaluated before dosing and at 4, 8, 26, and 48 hours after dosing. Blood samples (8 mL) from each of the volunteers were collected from an indwelling intravenous cannula inserted into a forearm vein before dosing and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, 24, and 48 hours after dosing. Ticlopidine concentrations were determined by a validated method using HPLC and ultraviolet detection. Adverse events were identified using general health-related questions, vital signs, physical examinations, ECGs, and laboratory tests. Results: A total of 24 healthy men participated in the study (mean [SD] age, 24.1 [4.3] years; weight, 66.6 [7.4] kg; height, 174.7 [5.0] cm). The baselinecorrected bleeding times were not significantly different between the ticlopidine-alone and ticlopidine/ Ginkgo biloba groups, and changes in platelet aggregation were not significantly different between the groups. Likewise, the pharmacokinetic parameters of ticlopidine were not significantly different between the groups; the geometric mean ratios of the ticlopidine/ Ginkgo biloba group to the ticlopidine-alone group were 1.03 (90% CI, 0.92–1.16) for Cmax, 1.08 (90% CI, 0.98–1.19) for AUC0-last, and 1.10 (90% CI, 1.00–1.20) for AUC0–∞. A total of 28 adverse events were reported: 11 in the ticlopidine-alone group and 17 in the ticlopidine/Ginkgo biloba group. The adverse events judged to be possibly related to ticlopidine in the ticlopidine-alone group were epigastric discomfort (2 cases), diarrhea (1), skin eruption (1), and a feeling of being cold (1) or hot (1). The adverse events judged to be related to ticlopidine or Ginkgo biloba in the ticlopidine/Ginkgo biloba group were epigastric discomfort (2), diarrhea (2), nausea (2), and headache (1). Conclusions: In this small group of healthy Korean men, the addition of a single dose of Ginkgo biloba extract did not prolong the bleeding time and was not associated with additional antiplatelet effects compared with the administration of ticlopidine alone. The coadministration of Ginkgo biloba extract with ticlopidine was not associated with any significant changes in the pharmacokinetic profile of ticlopidine compared with ticlopidine administered alone. [Copyright &y& Elsevier]

Background: Mirodenafil, a phosphodiesterase 5 inhibitor reported to be effective in the treatment of erectile dysfunction, is metabolized by cytochrome P450 (CYP) 3A4 to the active metabolite N-dehydroxyethyl mirodenafil. Mirodenafil may have drug-drug interactions with ketoconazole and/or rifampicin. Objective: The aim of this study was to investigate the effects of a potent inhibitor (ketoconazole) and inducer (rifampicin) of the CYP3A4 isozyme on the pharmacokinetics of mirodenafil to meet the regulatory requirements for the marketing of mirodenafil in Korea. Methods: An open-label, 1-sequence, 3-period, 3-treatment crossover study was conducted over 22 days in healthy Korean male volunteers. Each subject received 100 mg of mirodenafil in each of 3 study periods: mirodenafil alone (period 1); mirodenafil after pretreatment with ketoconazole 400 mg once daily for 3 days (period 2); and mirodenafil after pretreatment with rifampicin 600 mg once daily for 10 days (period 3). Serial blood samples were collected for pharmacokinetic analysis after the administration of mirodenafil in each study period. Plasma concentration-time data for mirodenafil and its major metabolite, N-dehydroxyethyl mirodenafil, were determined using LC-MS/MS and analyzed by a noncompartmental method. The results for mirodenafil coadministration with either ketoconazole or rifampicin were compared with those for mirodenafil alone. Adverse events (AEs) were identified by asking general health-related questions of the subjects, by physical examination, and by subject self-report throughout the study period. Results: Nineteen subjects were enrolled (mean [SD] age, 23.2 [2.76] years [range, 19–29 years]; weight, 69.3 [6.50] kg [range, 61.0–84.0 kg]; body mass index, 22.4 [1.77] kg/m2 [range, 20.0–26.0 kg/m2]) and 18 subjects completed the study. One subject discontinued the study due to protocol violation and was replaced. The AUC0−∞) of mirodenafil increased 5.04-fold (90% CI, 3.78–6.72) and the metabolic ratio decreased 0.21-fold after pretreatment with ketoconazole compared with mirodenafil alone. After pretreatment with rifampicin, the AUC0-X) of mirodenafil decreased 0.03-fold (90% CI, 0.02–0.05) and the metabolic ratio increased 2.9-fold. Twelve cases of headache, 6 of nasal congestion, 2 of feeling hot, 2 of epistaxis, and 1 each of dizziness, nausea, and somnolence were considered to be related to administration of mirodenafil. Twenty-eight AEs were reported in period 2 (in 68.4% of subjects), during which systemic exposure to mirodenafil was highest, whereas 7 AEs were reported in period 1 (in 31.6% of subjects) and 5 AEs in period 3 (in 16.7% of subjects). Conclusion: In these healthy Korean male volunteers, the coadministration of ketoconazole and rifampicin resulted in significant changes in systemic exposure to mirodenafil. [Copyright &y& Elsevier]

Background: Coadministration of glimepiride and metformin has been used to achieve glucose control. Because compliance with a multiple medication regimen can be difficult for some patients, combination tablets of glimepiride + metformin might be a suitable alternative for these patients. Objective: This study was conducted to compare the pharmacokinetics of test and reference formulations of glimepiride + metformin fixed-dose combination tablets under fasting conditions to meet the regulatory requirements for marketing approval of a new drug in Korea. Methods: This was a single-dose, randomized, open-label, 2-period, 2-way crossover study conducted between March 2007 and May 2007. Healthy fasting Korean men were randomized to 1 of 2 dosing sequences: a single oral administration of a fixed-dose glimepiride 1-mg + metformin 500-mg combination tablet (test) followed by single oral administration of a fixed-dose glimepiride 2 mg + metformin 500 mg combination tablet (reference), separated by a 1-week washout period between doses; or a single oral administration of a fixed-dose glimepiride 2-mg + metformin 500-mg combination tablet followed by single oral administration of a fixed-dose glimepiride 1 mg + metformin 500-mg combination tablet, separated by a 1-week washout period between doses. Serial samples of blood were collected up to 24 hours after oral administration, and drug concentrations in plasma were determined by HPLC-MS/MS. Tolerability was assessed based on adverse events and changes in clinical parameters. Serious adverse events included those that resulted in death, a life-threatening condition, congenital anomaly or birth defect, or required hospitalization or prolongation of existing hospitalization. Results: A total of 30 healthy male subjects (mean age, 25.6 years [range, 20–36 years]; weight, 69.5 kg [range, 58.2–90.7 kg]) participated in the study. After administration of the test and reference formulations, glimepiride was rapidly absorbed, reaching Cmax with a median Tmax of 1.75 and 2.0 hours, respectively, and then declined exponentially with an average t½ of 8.2 and 8.5 hours. The individual Cmax and AUClast of glimepiride were observed to be proportionally increased according to the administered glimepiride dose. The mean (SD) dose-normalized Cmax values of glimepiride 1 and 2 mg were 168.2 (54.9) and 149.9 (47.4) ng/mL/mg, respectively; the mean dose-normalized AUClast values of glimepiride 1 and 2 mg were 681.5 (190.3) and 635.8 (194.1) ng · h/mL/mg. Individual plots of dose-normalized Cmax and AUClast values identified a similarity between the 2 groups but no significant between-group differences. A total of 25 adverse events (12 after the test dose and 13 after the reference dose) were reported by 13 of the 30 subjects. All adverse events were considered mild. Twenty-one adverse events were considered related to the study drug (8 after the test dose and 13 after the reference dose). Adverse events believed to be related to the test formulation were diarrhea (4 cases), dizziness (1), headache (1), tingling sensation (1), and weakness (1). Adverse events believed to be related to the reference formulation were diarrhea (6 cases), headache (3), cold sweats (1), dyspepsia (1), epigastric discomfort (1), and lethargy (1). There were no clinically significant findings in the laboratory test results or vital sign monitoring during the study. There were no serious adverse events reported. Conclusions: The Cmax and AUClast of glimepiride increased proportionally according to the administered glimepiride dose in this study of healthy, fasting Korean men. The safety profiles of the 2 combination tablets were comparable. [Copyright &y& Elsevier]

Abstract: Background: LC15-0444 is a selective inhibitor of dipeptidyl peptidase (DPP) IV under investigation in Korea for the treatment of type 2 diabetes. Objective: The aim of this study was to investigate the pharmacokinetic (PK), pharmacodynamic (PD), and tolerability profiles of a single dose of LC15-0444 in healthy male subjects. Methods: A dose—block-randomized, double-blind, placebo-controlled, ascending single-dose, Phase I study was performed in healthy Korean male subjects assigned to receive 25, 50, 100, 200, 400, or 600 mg of LC15-0444 capsules. Blood and urine samples were collected up to 72 hours after administration. Plasma and urine drug concentrations were determined by tandem mass spectrometry coupled with high-performance liquid chromatography. DPP IV activity was measured by continuous spectrophotometric assay. An additional food effect study was performed in the 100-mg dose group; changes in PK and PD parameters after highfat diet were evaluated. Adverse events (AEs) were detected through investigator inquiries, spontaneous reports, and clinical evaluations such as physical examinations, vital sign measurements, 12-lead electrocardiography, clinical laboratory tests (eg, hematology, blood chemistry, coagulation, urinalysis), and computerized impedance cardiography. Results: Sixty Korean men (mean age, 25.3 years [range, 19-39 years]; weight, 68.3 kg [range, 53.6-84.9 kg]) were enrolled, providing 10 subjects for each dose group. After administration, LC15-0444 reached Tmax at 0.5 to 5.1 hours, and was eliminated with a t½ of 16.7 to 21.3 hours. The mean fraction of unchanged drug excreted in urine ranged from 0.21 to 0.34 and mean renal clearance was 15.5 to 23.6 L/h. The dose-normalized AUC exhibited dose-linearity over the range of 50 to 400 mg. All doses of LC15-0444 =200 mg were found to inhibit 80% of DPP IV activity for 24 hours. High-fat diet did not significantly influence the AUC of LC15-0444. LC15-0444 was generally well tolerated. None of the subjects developed any serious clinical or laboratory AEs or discontinued the study due to an AE. All AEs were mild or moderate, and no dose-related trends were observed. Fortysix AEs were reported in 18 subjects (30.0%). AEs considered to be related to the study drug were headache (6 cases), dizziness (2), nausea (1), epistaxis (1), and increased heart rate (1). All AEs resolved spontaneously. Conclusions: A single dose of LC15-0444 exhibited linear PK properties over the range of 50 to 400 mg in these healthy Korean male subjects. PK characteristics were not significantly influenced by food. In addition, doses ≥200 mg of LC15-0444 inhibited plasma DPP IV activity by >80% over a 24-hour dosing interval, and a 600-mg dose increased active glucagon-like peptide-1 levels after a standardized meal. LC15-0444 was generally well tolerated. [Copyright &y& Elsevier]