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In most Wuchereria bancrofti and Brugia malayi infections, the microfilaria are found in the blood in greatest number between 10 p.m. and 2 a.m., indicating that chronotherapy may be beneficial in treating such infections. This study reports the influence of time of administration on the pharmacokinetics of diethylcarbamazine (DEC) in healthy volunteers. The study was conducted in 12 healthy volunteers by administering a 150 mg single oral dose of diethylcarbamazine citrate at 0600 or 1800 h in a balanced crossover design with the approval of an institutional ethics committee. The subjects fasted for about 10 hours before and 3 hours after drug treatment. Blood samples were collected at predetermined time intervals, and the drug content in the serum was estimated using HPLC with an electrochemical detector. Pharmacokinetic analysis was performed using noncompartmental methods employing WinNonlin (version 3.1), and the means of various pharmacokinetic parameters were compared for any dosing time-related changes using a paired t-test at a probability level of 95%. The mean +/- SD values of pharmacokinetic parameters of DEC for the treatments at 0600 versus 1800 h were as follows: Cmax, 500+/-227 versus 637+/-401 ng/ml; tmax, 2.3+/-0.7 versus 2.7+/-1 h; Ka, 2.23+/-0.72 versus 1.96+/-0.97 h(-1); t1/2, 14.6+/-6.7 versus 11.4+/-4.9 h; AUC0-t, 5,334+/-1,853 versus 6,901+/-4,203 ng x h/ml; AUC0-infinity, 5,840+/-1,922 versus 7,220+/-4,205 ng x h/ml; CL/F, 36,058+/-19,011 versus 32,189+/-25,293 ml/h/kg; Vd/F, 570+/-225 versus 533+/-447 L; and MRT 17.7+/-5.9 versus 15.3+/-5.2 h. None of the parameters was significantly changed (p > 0.05) as a function of time of administration. [ABSTRACT FROM AUTHOR]

Introduction: Atogepant is a calcitonin gene-related peptide receptor antagonist approved for the preventive treatment of migraine in adults in the USA, EU, and several other countries. The objectives of this study were to evaluate the pharmacokinetics (PK) and dose proportionality of atogepant in healthy Japanese participants, evaluate the safety and tolerability of atogepant in Japanese participants, and explore the differences in the PK and safety of atogepant in Japanese vs white participants., Methods: A total of 50 participants (40 Japanese and 10 white) were enrolled into five cohorts; Japanese cohorts were randomized in a 4:1 ratio to atogepant (10 mg, 30 mg, or 60 mg daily dosing and 60 mg twice daily) or placebo. The white participants were randomized to atogepant (60 mg twice daily) or placebo. Doses were administered on day 1 and days 3-8, with those on days 1 and 8 administered after an overnight fast., Results: In Japanese participants, atogepant exposure increased with dose, and there was no accumulation with once-daily dosing and minimal (~ 20%) accumulation with twice-daily dosing. Atogepant steady-state exposure appeared to be marginally lower in Japanese participants compared with white participants and was well tolerated. There were no treatment-related adverse events, serious adverse events, clinically significant changes in vital signs, or signs of suicidal ideation or behaviors., Conclusion: Atogepant exposure increased with dose in healthy Japanese participants and was well tolerated within the dose range tested., Competing Interests: Declarations. Conflict of Interest: Ramesh Boinpally and Brian McNamee are employees of AbbVie Inc. and may hold AbbVie stock. Ethical Approval: The investigator obtained approval of the study protocol from a properly constituted institutional review board (Aspire IRB, Santee, CA, USA) prior to study initiation. All participants provided written informed consent. The study was conducted in accordance with the ICH E6 guideline for good clinical practice and the principles of the Declaration of Helsinki., (© 2025. The Author(s).)

Atogepant, an oral calcitonin gene-related peptide receptor antagonist, is approved for the preventive treatment of migraine. A phase 1, open-label, single-dose, 2-period crossover study evaluated the effect of a high-fat meal on the pharmacokinetics and safety of atogepant in 20 healthy adults. Administration of atogepant 60 mg immediate-release (IR) tablets under fed conditions reduced the area under the plasma concentration-time curve (AUC) from 0 to time t and from 0 to time infinity by approximately 18% and reduced the maximum plasma concentration (C max ) by 22%. The 90% confidence intervals for the geometric mean ratios of C max and AUC were not contained within the bioequivalence limits of 80%-125%. There was no change in the median time to maximum plasma concentration in the fed versus fasted state. The incidence of treatment-emergent adverse events (TEAEs) was similar between fed and fasted conditions. Four TEAEs were considered related to study intervention and were reported after participants received atogepant under fasted conditions (3 participants). A single-dose atogepant 60 mg IR tablet was safe and tolerated under both fed and fasted states. Due to the wide effective dose range of 10-60 mg/day for atogepant for the preventive treatment of migraine, the food effect on its pharmacokinetics is not considered clinically relevant., (© 2024 Abbvie. Clinical Pharmacology in Drug Development published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Context: Food effects were defined as positive, when coadministration of food causes an increase in the extent of absorption (AUC(0-∞)) of a drug when compared with fasted state drug administration and no effect when coadministration of food causes no change in AUC(0-∞). In general, low solubility drugs exhibit positive food effects due to improved solubility in fed state administration. But, certain high-solubility and high-permeability drugs that undergo extensive presystemic metabolism exhibit positive food effects because of the increased splanchnic hepatic blood flow in the fed state presumably causing a fraction of drug to bypass first-pass metabolism during absorption., Objective: In this study, systemic clearance (Cl) of structurally diverse high-permeability and high-solubility drugs was correlated to their food effects to explore whether drugs undergoing low clearance exhibited no food effects and drugs undergoing high clearance exhibited positive food effects., Methods: Six drugs exhibiting positive food effects and nine drugs exhibiting no food effects (for comparison) were selected for linear regression analysis., Results: Regression analysis of the selected drugs indicated that percent food effects correlated linearly to Cl and fitted the equation: percent food effects = 0.9163 × Cl - 6.4789. The R(2), p-value and power of the regression model were >0.88, 0.9999, respectively indicating the direct correlation between Cl and food effects of the selected model drugs; other statistical tests validated the model., Conclusion: The model indicated that high-solubility and high-permeability drugs undergoing Cl of more than 27 L/h may exhibit statistically significant positive food effects.

As part of an ongoing phase 1 study, we studied the excretion of XK469 and its metabolism in patients and in vitro. Five primary metabolites were identified by HPLC/MS/MS. An oxidized product formed by cytosolic aldehyde oxidase was the predominant species both in urine and human hepatocytes in vitro. Conjugates of XK469 with glycine, taurine, and glucuronic acid, as well as the microsomal product, 4-oxo-XK469, were also found in urine and in vitro, but none were major contributors to the mass balance for XK469 elimination. Based upon the relative concentrations circulating in plasma, systemic exposure to parent drug was 100-fold higher than for the metabolites. Thus, both toxicity and efficacy of XK469 are most likely to be produced by the parent molecule, rather than the metabolites. Urinary recovery of parent drug was low (2% of dose in 24 h), partly because of the long half-life of XK469 (approximately 3 days). In addition, the metabolite profile in urine indicates that only 25% of the XK469-derived material was unchanged drug. Thus, urinary excretion was not a major factor in XK469 elimination. Variations in systemic exposure to XK469 will be strongly influenced by factors that alter the activity of aldehyde oxidase, including pharmacogenetics, enzyme inhibition, and enzyme induction, but no specific modifiers have been reported. The multiday half-life of XK469 hampered our ability to obtain a complete mass balance, and the possibility exists that other routes, such as biliary excretion, may also play a substantial role in XK469 disposition.

Purpose: BMS-247550 is a semisynthetic derivative of epothilone B with mechanism of action analogous to paclitaxel. It has shown impressive antitumor activity in preclinical studies including in taxane-resistant models. We conducted a phase I trial, based on accelerated titration "2B" design, of BMS-247550 given as a 1-hour infusion every 3 weeks., Experimental Design: Seventeen patients (M:F, 10:7; median age, 54 years; performance status, 0-2) were treated on the trial. Forty-five cycles (1-9 cycles) of BMS-247550 were given at dosages ranging from 7.4 to 56 mg/m2. All patients received prophylaxis for hypersensitivity reactions, related to Cremophor-EL, with steroids and histamine antagonists., Results: First-course dose-limiting toxicity (DLT) was observed in two of three patients at 56 mg/m2 (neutropenic sepsis, prolonged grade 4 neutropenia) and in one of six patients at 40 mg/m2. Nonhematologic grade 3 to 4 toxicities observed were emesis and fatigue and they occurred only at 56 mg/m2. Grade 1 to 2 peripheral neuropathy was also observed. Other grade 1 to 2 toxicities were myalgias, arthralgias, rash, hand/foot syndrome, and mucositis. AUC and C(max) seemed proportional to the dose and the DLT. Development of neutropenia with BMS-247550 is related to the duration of drug exposure above a threshold., Conclusions: The maximum tolerated dose (MTD) of BMS-247550 is 40 mg/m2 given every 3 weeks. Neutropenia is the DLT. The accelerated titration "2B" design may help in determining MTD with fewer patients enrolled and more being treated closer to the MTD. However, the accelerated titration design did not seem to shorten the study duration.

Objective: To identify activity and biological mechanisms of intratumoral (IT) docetaxel on head and neck squamous cell carcinoma (HNSCC)., Methods: Docetaxel IT therapy was tested in xenograft models of 2 HNSCC lines, HN30 and HN12. The overall and disease-free survival rates, tumor growth, and toxic effects were measured. The pharmacokinetic profiles of docetaxel in plasma and tumor were compared after IT and intravenous (IV) administration. Comparisons between common and supradoses of docetaxel with regard to expression of regulators in the cell cycle, apoptosis, and signal transduction pathways were determined using Western blot analysis., Results: In the HN30 and HN12 xenograft models, IT docetaxel improved overall as well as disease-free survival and reversed tumor growth. The only toxic effects noted were local (alopecia and skin breakdown). Skin breakdown resolved in all cases. At equivalent dosing levels, IT docetaxel achieved a 26-fold higher peak tumor concentration and 24-fold longer tumor exposure than IV treatment. Furthermore, limited plasma exposure was noted with IT docetaxel. Supradose levels of docetaxel produced distinct protein expression patterns for regulators of the cell cycle (cyclins A and B, p21, and p27), apoptosis (cleaved caspase-3 and cleaved PARP), and signal transduction (EGFR, pEGFR, pc-Jun, and pERK) in HNSCC, which supports a distinctive mechanism of action for supradose docetaxel levels. Since levels of cleaved caspase-3 and PARP, markers of apoptosis, were only elevated with lower doses, the observed cell death at supradose levels was probably due to necrosis., Conclusions: Injections of IT docetaxel at usual and supradoses are associated with a pharmacokinetic profile and biological mechanism distinct from those observed with usual IV doses. It is calculated that IT therapy in men will increase peak concentrations of docetaxel in tumors by 1000-fold over the conventional IV dose used clinically. These preclinical results support further testing of IT docetaxel in HNSCC.

Purpose: To determine the oral bioavailability of R-XK469, a water-soluble investigational anticancer agent undergoing phase I clinical trials as an intravenous product., Methods: R-XK469 was administered to two groups of catheterized Sprague-Dawley rats via the oral and IV routes at a dose of 10 mg/kg and blood samples were collected at predetermined times. XK469 in plasma samples was quantified using a HPLC method. The pharmacokinetic parameters were computed using WinNonlin 4.0.1 software., Results: The pharmacokinetic parameters of XK469 following oral and IV administrations, respectively, were (mean+/-SD): C(max) 138+/-64 and 404 +/- 355 microg/ml; AUC(0-infinity) 2381 +/- 773 and 2854 +/- 1924 microg h/ml; and elimination half-life (T(1/2)) 12.9 +/- 5.8 and 13.5 +/- 7.8 h T(max) was 2.92+/-1.92 h following oral dosing. Oral R-XK469 was 83% bioavailable., Conclusion: Together with the antitumor efficacy of oral XK469 shown in preclinical models and its schedule dependency, these results indicate the promise of developing an oral dosage form of R-XK469 for clinical development.

Purpose: Fenretinide, a synthetic form of retinoid, induced apoptosis even in chemotherapy resistant cell lines. A phase II study was hence conducted to evaluate toxicity and efficacy of fenretinide in metastatic renal cancer., Methods: Eligibility included unresectable or metastatic renal cell carcinoma (RCC), adequate organ function and Zubrod performance status < or =2. Prior immunotherapy and a maximum of one prior chemotherapy regimen were allowed. Fenretinide was administered at a dose of 900 mg/m(2) twice daily orally for 7 days in a 21-day cycle. Toxicity was assessed at the start of each cycle, and response every 2 cycles., Results: Nineteen eligible patients enrolled of which fifteen had visceral/bone metastases. Seventeen patients had prior nephrectomy and 11 had prior immunotherapy. 76 cycles of therapy were delivered. Therapy was very well tolerated with few severe toxicities consisting of thrombosis in 1 individual and grade 3 fatigue, nausea and diarrhea in 1 patient. 5 patients had grade 2 nyctalopia and 3 patients had transient grade 2 visual toxicity. No objective responses were noted. Stable disease was seen in seven of nineteen cases (37%, 90% C.I. 0.21-0.59). Median time to progression was 1.5 months and median duration of stable disease was 5.8 months (90% C.I. 3.0-8.4). Median survival was 10 months. Tumor fenretinide levels were obtained in three patients and were in the lower end of the therapeutic range., Conclusion: Fenretinide was well tolerated but demonstrated minimal activity that was consistent with results of intratumoral drug measurements. Strategies are needed that will increase systemic and tumor levels of fenretinide.

Site-specific immunosuppression with topical cyclosporin A (CsA) has broad clinical implications in the treatment of skin disorders like psoriasis, pyoderma gangrenosum, lichen planus, cutaneous graft-versus-host disease and contact hypersensitivity and the temporary treatment of skin allografts on burn wounds. However, like any other peptide drug, its skin delivery is hindered by the barrier property of stratum corneum and the physicochemical properties of CsA. We have attempted to deliver CsA across human cadaver epidermis in vitro using colloidal systems like microemulsion and lecithin vesicles and iontophoresis. Although, passive diffusion did not result in permeation of quantifiable amounts of CsA, anodal iontophoresis of the negatively charged colloidal systems facilitated the permeation. Electroosmosis and compromised epidermis might have contributed to the higher skin flux. Lecithin vesicles were better than microemulsion for the iontophoretic delivery of CsA and appear to have potential in site-specific immunosuppression.

Skin penetration of topically applied diclofenac is important for the treatment of rheumatic diseases and actinic keratoses. We have studied the permeation of diclofenac across human cadaver epidermis in-vitro from four lecithin vesicle formulations and a few marketed semi-solid preparations. The lecithin vesicle formulations were prepared by dissolving the lipid contents (lecithin and sodium cholate) in a 1:1 mixture of methanol-chloroform, evaporating the solvents under vacuum, and hydrating the lipid layer with the drug solution in water or 10% ethanol. The vesicles were sonicated for 5 min to reduce the vesicle size and their size and Zeta potential were characterized. The cumulative amount and maximum flux of diclofenac was 69.7+/-40.3 micrograms and 4.77+/-3.16 micrograms/hcm(2) from lecithin vesicles containing sodium cholate and 10% ethanol, and is the highest of all formulations studied. The cumulative amount and mean maximum flux obtained from other formulations were in the range of 2.46+/-1.98-29.9+/-10.1 micrograms and 0.53+/-0.46-3.61+/-0.86 micrograms/hcm(2). Based on the results, lecithin vesicles of diclofenac appear to be advantageous for the topical delivery of diclofenac.

Purpose: To compare the pharmacokinetics and tissue distribution (both normal and tumor) of cryptophycin 52 (C-52) and its putative chlorohydrin prodrug cryptophycin 55 (C-55) in a murine model and to investigate a possible mechanism behind the superior activity of C-55., Methods: Mammary adenocarcinoma 16/c tumor-bearing mice were treated with an i.v. bolus of 11 mg/kg C-52 or 38 mg/kg C-55 in Cremophor-alcohol. At predetermined time intervals, C-52 and C-55 concentrations in plasma, liver, kidney, small intestine and tumors were measured using a previously described HPLC method. Pharmacokinetic parameters were computed using noncompartmental methods. Tissue (both normal and tumor) to plasma ratios as a function of time were also calculated for comparison., Results: Both C-52 and C-55 were rapidly distributed into different tissues including tumors following i.v. administration. However, the affinities of these compounds towards different tissues were different. Thus, the half-lives (minutes) of C-55 were in the decreasing order liver (725), intestine (494), tumor (206), kidney (62) and plasma (44), whereas the AUC values (microg x min/ml) were in the order tumor (9077), liver (7734), kidney (6790), plasma (2372) and intestine (2234). For C-52, the half-lives (minutes) were in the decreasing order liver (1333), kidney (718), intestine (389), tumor (181) and plasma (35), and the AUC values (microg x min/ml) were in the order kidney (1164), liver (609), intestine (487), plasma (457) and tumor (442). The relative exposures to C-52 after i.v. injection of C-55 were plasma 3.9%, tumor 80.8%, kidney 3.4%, liver 1.1% and intestine 2.8%. Although plasma exposure to C-52 following C-55 administration was relatively small, the use of C-55 to deliver C-52 increased the retention of C-52 and its AUC in tumor compared to direct injection of C-52. Simultaneously, this approach shortened C-52 retention in all normal tissues studied., Conclusions: The distribution of C-55 and its bioconversion to C-52 in different organs and tumor tissue observed in this study suggest the ability of C-55 to target tumor tissue, creating a depot of C-52 in tumor. Increased C-52 exposure of tumor, with concomitant decreased exposure of normal tissue, is a contributing factor to the superior activity of C-55 versus C-52. However, except in the case of tumor tissue in which 81% of C-55 converts to C-52, only a minor amount of C-55 may serve as a prodrug for C-52, whereas the majority is handled by the biosystem through a different route of elimination. Tissue distribution combined with rate of conversion may be an important determinant of the relative effectiveness of other epoxide-chlorohydrin pairs of cryptophycins.

The spicamycin derivative KRN5500 was considered as a potential anti-cancer agent based on in vitro and preclinical studies. A Phase I study involving 24 cancer patients in whom tumors were refractory to all other conventional therapies was conducted to determine the dose limiting toxicity, maximum tolerated dose, effectiveness, and pharmacokinetic parameters of this drug administered by 1-h IV infusion daily for five consecutive days every 3 weeks. Using an accelerated dose titration strategy, 8.4 mg/m2/d x 5 days was the maximum administered dose. Severe gastrointestinal and hepatic toxicities were observed at doses at or above 4.3 mg/m2/d x 5. The recommended Phase II dose i s 4.3mg/m2/d x 5. The distribution of KRN5500 followed a two-compartment model, and clearance did not decrease significantly over the dose range 0.8-8.4 mg/m2/d x 5. No significant correlation was observed between plasma levels and toxicity. No tumor responses were observed among the 14 patients evaluable for response.

Hormonal changes during the different phases of menstrual cycle may influence drug disposition. The objective of this study was to investigate the influence of the menstrual cycle on the pharmacokinetics of paracetamol through salivary compartment in young healthy Indian women (n = 12) with regular menstrual cycles. The subjects received an oral dose of 1 g paracetamol on the 3rd, 13th, and 23rd days of their menstrual cycle in a 3 x 3 randomized crossover design. Saliva samples were collected at predetermined time intervals and the paracetamol content in them was estimated using an established HPLC method. The pharmacokinetics of paracetamol was worked out using a model-independent method employing WinNonlin 3.1. The mean Cmax of paracetamol was significantly (p < 0.05) lower (31.5%) in the ovulatory phase than in the follicular phase. The mean AUC0-t and AUC0-infinity values were significantly (p < 0.05) lower in the ovulatory phase than those in the luteal phase. These changes could be due to increased first-pass metabolism and decreased bioavailability of paracetamol during the ovulatory phase.

The time-dependent influence of pentoxifylline (PTX) on the pharmacokinetics of carbamazepine (CBZ) was studied after single-dose oral administration of 100 mg CBZ either alone or in combination with 400 mg PTX at 10:00 and 22:00 h. Serum samples were collected at predetermined time intervals and analysed for unchanged CBZ using high-performance liquid chromatography. The pharmacokinetic parameters of CBZ were calculated using the model-independent method. PTX reduced the rate (Tmax, 8.58 +/- 2.64 vs 5.66 +/- 1.44 h; K(a); 0.47 +/- 0.14 vs 0.72 +/- 0.19 h(-1)), but not the extent of CBZ absorption at 22:00 h treatment. However, such a change was not observed for 10:00 h treatment. No significant changes were observed in other pharmacokinetic parameters of CBZ under the influence of PTX for both 10:00 h as well as 22:00 h treatments. The clinical significance of the time-dependent influence of PTX on the rate of absorption of CBZ will be revealed upon extension of the study to patients., (Copyright 2001 Academic Press.)

Rhythms in the onset and symptoms of several diseases are well established. Migraine is a disorder that exhibits periodicity in its symptoms and so chronotherapy may be beneficial in treating the problem. Designing a chronotherapeutic schedule requires chronopharmacokinetic and chronopharmacodynamic data of the drugs prescribed. We have studied the chronopharmacokinetics of sumatriptan, a drug of choice in migraine treatment. Twelve healthy male volunteers were treated with 100 mg sumatriptan orally at 0700, 1300, 1900 and 0100 h in a randomized 4 x 4 Latin square crossover design, with a wash-out period of one week. Serum samples were analysed by high performance liquid chromatography with an electrochemical detector. Pharmacokinetic parameters were calculated using noncompartmental methods. The pharmacokinetic parameters were analysed using analysis of variance and a two-tailed paired t-test at the probability of 95%. The mean peak serum concentration following the 0700 h administration (Cmax; 59.09 +/- 10.53 ng mL(-1)) was significantly (P < 0.05; n = 12) higher than after the 1900 h administration (Cmax 41.88 +/- 12.21 ngmL(-1)). The mean area under the serum concentration-time curve from time zero to the last time-point (AUCo-t), the area under the serum concentration-time curve from zero to infinity (AUC 0-infinity), and the area under the first moment curve (AUMC) were significantly (P < 0.05; n = 12) higher following the 0700 and 0100 h administrations than after the 1900 h administration. Following administration at 0700 h, the mean oral clearance (CLs/f; 781 +/- 186 mL h(- 1) kg(-1)) and the apparent volume of distribution (Vd/f; 2,379 +/- 684) were significantly lower (P < 0.05; n = 12) than after the 1900 h administration (CLs/f 1,208 +/- 458 mL h(-1) kg(-1), Vd/f 4,655 +/- 2,096 mL kg(-1)). The mean Vd/f value was again lower after the 1300h administration than after the 1900 h administration (2,763 +/- 1,417 vs 4,655 +/- 2,096 mL kg(-1); P < 0.05; n = 12). The variations may be due to the time dependent changes in the extent of absorption and/or circadian variations in hepatic blood flow.

Twelve healthy volunteers were treated with 400 mg pentoxifylline at 1000 and 2200 hours in a randomized crossover design with a washout period of 1 week. Serum and saliva samples were analyzed for unchanged pentoxifylline by high-performance liquid chromatography. Saliva to serum ratios and pharmacokinetic parameters of pentoxifylline were calculated. Significant (p < 0.05) correlation between serum and salivary levels of pentoxifylline was observed for the treatments at 1000 and 2200 hours. Although the mean saliva/serum ratios of pentoxifylline in the postabsorption phase were found to be higher for the 2200-hour treatment than the 1000-hour treatment, this difference was not statistically significant (p > 0.05). Further, no significant (p > 0.05) difference was noted between the mean pharmacokinetic parameters of pentoxifylline whether computed through serum or through salivary levels for either treatment. Hence, saliva can be used in place of serum/plasma in pharmacokinetic and interaction studies of pentoxifylline.