Search

Despite a relatively low prevalence of primary brain tumors, they continuously attract scientific interest because of the complexity of their treatment due to their location behind the blood-brain barrier. The main challenge in treatment of brain tumors is not the efficacy of the drugs, per se, but the low efficiency of drug delivery to malignant cells. At the core of the problem is the complex structure of the blood-brain barrier. Nowadays, there is evidence supporting the claim that bile acids have the ability to cross the blood-brain barrier. That ability can be exploited by taking a part in novel drug carrier designs. Bile acids represent a drug carrier system as a part of a mixed micelle composition, bilosomes and conjugates with various drugs. This review discusses the current knowledge related to bile acid molecules as drug penetration modifying agents, with the focus on central nervous system antitumor drug delivery.

Since its discovery in 1945, methotrexate has become a standard therapy for number of diseases, including oncological, inflammatory and pulmonary ones. Major physiological interactions of methotrexate include folate pathway, adenosine, prostaglandins, leukotrienes and cytokines. Methotrexate is used in treatment of pulmonary sarcoidosis as a second line therapy and is drug of choice in patients who are not candidates for corticosteroid therapy, with recommended starting weekly dose of 5-15 mg. Number of studies dealt with methotrexate use in rheumatoid arthritis and oncological patients. Authors are conducting research on oral methotrexate use and pharmacokinetics in chronic sarcoidosis patients and have performed literature research to better understand molecular mechanisms of methotrexate action as well as high level pharmacokinetic considerations. Polyglutamation of methotrexate affects its pharmacokinetic and pharmacodynamic properties and prolongs its effect. Bile excretion plays significant role due to extensive enterohepatic recirculation, although majority of methotrexate is excreted through urine. Better understanding of its pharmacokinetic properties in sarcoidosis patients warrant optimizing therapy when corticosteroids are contraindicated in these patients.

This journal is © The Royal Society of Chemistry. This study was designed to define total protein, phenol and flavonoid content as well as LC-MS/MS phenolic profile related to antioxidant and antidiabetic activity of ethanolic (EtOH) and water extracts of G. pfeifferi and G. resinaceum. G. resinaceum water extract possessed the highest ability to scavenge DPPH and O2-, while the EtOH extract of the same species showed better activity on NO related to other extracts. The highest level of bioactive compounds was determined generally in EtOH extracts. Antidiabetic action was evaluated by the oral glucose tolerance test (OGTT) and histological examination of pancreas and liver in normoglycemic and alloxan-induced diabetic animals. Histological examination of pancreatic tissue demonstrated that G. pfeifferi extracts have protective effects. To conclude, analysed extracts could be considered as a promising candidate for further research with the aim to promote antidiabetic activity, which is for the first time reported for G. pfeifferi.

Methotrexate is an anti-inflammatory and anticancer drug that has been used in the treatment of various oncological and inflammatory diseases (such as rheumatoid arthritis, inflammatory bowel disease, psoriasis, sarcoidosis, etc.). Scientists are working on finding optimal formulation that will maintain its efficacy and improve safety and nanoparticles have shown to be carriers with great potential as they protect the drug from degradation while at the same time they increase absorption. In vivo and in vitro studies of numerous nanoparticle preparations have showed that they generally have appropriate characteristics and can be carriers for targeted delivery of methotrexate to the tissues affected by disease. Topical preparations of methotrexate, mainly for the treatment of psoriasis, have also been assessed in various research and have showed promising results. Further research is warranted by the obtained results and will hopefully lead to new methotrexate formulations that will be approved by regulatory authorities and used instead of existing ones to improve efficacy of the drug and patients' safety.

High-dose methotrexate (HD-MTX) is the mainstream therapy of current acute lymphoblastic leukemia (ALL) regimens, but frequent intra- and interindividual differences in the clinical response to HD-MTX lead to chemotherapeutic interruption or discontinuation. The exact mechanism of transport across the cell membrane and the disposition of active methotrexate metabolites—methotrexate polyglutamates (MTXPGs)—are not well described in the literature. The aim of this study was to gain more insight into the plasma distribution of methotrexate and MTXPGs in pediatric patients with ALL and to clarify the obscure pathways of MTXPGs. We prospectively measured the concentrations of MTXPG1–7 in plasma samples from three male pediatric patients treated with HD-MTX and leucovorin rescue according to the IC-BFM 2009 protocol using liquid chromatography–mass spectrometry (LC-MS). Blood samples were obtained at 24, 36, 42, and 48 h after the start of HD-MTX treatment. Noticeable plasma concentrations of MTXPGs with a 2.2-fold interpatient variability were detected. The highest interindividual variability in total plasma MTXPG concentration was observed at 36 h, and ranged from 13.78 to 30.82 μmol/L. Among all patients, the predominant polyglutamate types in relation to the total plasma MTXPG concentration at each time point were MTXPG3 (16.71–30.02%) and MTXPG5 (26.23–38.60%), while MTXPG7 was the least abundant MTXPG (3.22–5.02%). The presence of MTXPGs in plasma of patients with ALL could be related to the action of ABC efflux transporters on blood cells and hepatocytes resulting from the administration of high doses of methotrexate. This study may not draw definitive conclusions, but it does reduce uncertainty about the dynamics of methotrexate and its active metabolites, which may be of vital importance for achieving a clinical response.

High concentrations of pesticides and toxic metal pollutants in the environment, often present in surface waters in nature, can accumulate in wild animals and are a significant public health concern. Serbia is a moderately developed, south European country in transition, with a long tradition in agriculture, particularly in the northern part, Vojvodina. Our study aimed to assess the presence of pesticides and to measure concentrations of toxic metals in the district of Backi Petrovac, Vojvodina. Water samples were analyzed from canals, ditches, fish from the canals and wild animals caught in the Backi Petrovac district. We identified nine pesticides in water samples. Of all detected pesticides, one was a hormonal disruptor. There were no pesticides in animals, fish and organs in a concentration above the limit of detection (LOD) in observed periods. The concentrations of toxic metals detected in superficial water (Cd, Pb, Hg, As, Mn, Cu) were below the permitted limits, as well as the concentrations of Cd, Pb, Hg, As and Mn in the whole bodies of fish. Concentrations in kidneys and livers of wild animals (rabbit and roe deer) were below the permitted limits, with the exception of cadmium, whose concentrations in some animal samples were above the permitted limit. Based on the obtained results, we concluded that in the developed agricultural region unencumbered by heavy industry, pollution by pesticides and heavy metals can be controlled.

This article presents a compact, low-cost, robust, and flexible test platform for determining the concentration of drugs in fluids. This device is based on a PVC foil card containing copper conductive foils in which disposable paper test strips are inserted. The paper test strips are overlaid with deposition of multiwalled carbon nanotubes (MWCNTs) acting as a sensing layer. When a paper test strip is inserted into the test card, the conductive path between two copper lines is established. A drop of test fluid on the sensing MWCNT layer changes the conductivity in a concentration-dependent manner, enabling calculation of the drug concentration after measurement of the electrical resistance at the copper terminals. An equivalent electrical circuit was also proposed to model the response of the fabricated sensor. It was shown that model parameters are dependent on the concentration of the cytostatic drug methotrexate. Additionally, the fabricated sensor demonstrated the ability to differentiate the same concentration of methotrexate and cyclophosphamide. The complete readout electronics and polynomial transfer function for calculating drug concentrations were also developed and are presented.

Gut microbiota and bile acids possess the ability to modify absorption and pharmacokinetic profile of numerous drugs. Since the variability of gliclazide response in patients cannot be explained only by genetic factors, the influence of gut microbiota and bile acids should be considered. The aim of this study was to determine the effects of probiotic bacteria and bile acids on the gliclazide permeability. The permeability of gliclazide with and without probiotic bacteria and bile acids (cholic acid, CA and deoxycholic acid, DCA) was tested using in vitro PAMPA model, at three different pH values (5.8, 6.5 and 7.4). Concentrations of gliclazide were determined by HPLC analysis. The interactions of gliclazide and bile acids were also investigated by molecular mechanics calculations (MM2). Probiotic bacteria significantly increased the permeability of gliclazide across the PAMPA membrane at all observed pH values while the total amount of gliclazide during incubation with bacteria was significantly reduced at pH 7.4, which could be a consequence of partial metabolism of the drug by enzymes of probiotic bacteria. Bile acids decreased the permeability of gliclazide through PAMPA membrane, with more pronounced effects of DCA, by forming more stable complexes with gliclazide. Given that probiotic bacteria and bile acids are naturally present in the gut and that each individual has a specific bacterial fingerprint, future research should extend the explanation of their effect on the gliclazide bioavailability and therapy individualization in in vivo conditions.

Gliclazide is a drug commonly used in type 2 diabetes mellitus. Recently, gliclazide has shown desirable pharmacological effects such as immunoregulatory and anti-clotting effects, which suggests potential applications in type 1 diabetes mellitus (T1DM). Gliclazide has variable absorption after oral administration, and thus using targeted-delivery techniques, such as microencapsulation, may optimise gliclazide absorption and potential applications in T1DM. Bile acids such as cholic acid have shown microcapsule-stabilising and controlled-release effects, and thus their incorporation into gliclazide microcapsules may further optimise gliclazide release, absorption and antidiabetic effects. Accordingly, this study aimed to examine the hypoglycaemic effects of gliclazide microcapsules with and without cholic acid, in a rat model of T1DM. Thirty-five alloxan-induced T1DM rats were randomly divided into five equal groups and gavaged a single dose of empty microcapsules, gliclazide, gliclazide microcapsules, gliclazide-cholic acid or gliclazide-cholic acid microcapsules. Blood samples were collected over 10 h post-dose and analysed for blood glucose and gliclazide serum concentrations. Gliclazide microcapsules exerted a hypoglycaemic effect in the diabetic rats, and cholic acid incorporation diminished the hypoglycaemic effects, which suggests the lack of synergistic effects between gliclazide and cholic acid. In addition, neither microencapsulation nor cholic acid incorporation optimised gliclazide absorption which suggests that hypoglycaemic effects of gliclazide are independent of its absorption and serum concentrations. This also suggests that hypoglycaemic effects of gliclazide may be associated with gut-metabolic activation rather than gut-targeted delivery and systemic absorption. Gliclazide microcapsules exerted hypoglycaemic effects in T1DM rats independent of insulin and thus may have potentials in treatment of T1DM.

Background/Aim: Gliclazide is one of the most commonly prescribed oral anti-hyperglycaemic therapies in type 2 diabetes mellitus (T2D). Recently reported additional beneficial pharmacological properties of gliclazide, including immunomodulatory and anticoagulant activities, suggested its potential application in treatment of type 1 diabetes mellitus (T1D). However, following oral administration, gliclazide was shown to have poor and variable absorption directing research into development of novel pharmaceutical delivery systems of gliclazide suitable for T1D. Since bile acids have previously demonstrated stabilising and controlled-release effects on microcapsules, their use for preparation of microcapsules of gliclazide may lead to improvements in gliclazide release, absorption and antidiabetic effects. This investigation was aimed to evaluate drug absorption profiles and hypoglycaemic effects of alginate-based microcapsules of gliclazide, prepared together with or without cholic acid, in healthy rats. Methods: Thirty healthy Wistar rats with confirmed normal glucose blood concentration were allocated into five groups and administered with a single dose of either vehicle microcapsules, gliclazide in suspension, gliclazide microcapsules, gliclazide in suspension together with cholic acid or microencapsulated gliclazide in combination with cholic acid. Following respective gliclazide dose, blood was sampled over next 10 hours and blood glucose levels and gliclazide serum concentrations were measured. Results: This analysis demonstrated altered effects of different gliclazide formulations in healthy rats with the highest gliclazide absorption mirrored by the most profound hypoglycaemic effect being achieved after its oral administration as a suspension (p

This study was designed to define total protein, phenol and flavonoid content as well as LC-MS/MS phenolic profile related to antioxidant and antidiabetic activity of ethanolic (EtOH) and water extracts of

Introduction: Inter-individual differences in gut microflora composition may affect drug metabolism and overall therapeutic response. Gliclazide is a drug characterized by large inter-individual differences in therapeutic response; however, the causes of these differences are not fully explained and may be the outcome of microbial biotransformation. Recently, great attention has been paid to studies on bile acid (BA) interactions with gut microflora and the role of BAs in the modification of drug transport through biological membranes. The Aim: Considering the assumption of gliclazide-probiotic-BAs interactions, the aim of the study was to investigate the transport and biotransformation of gliclazide in probiotic bacteria, as well as the effects of deoxycholic acid (DCA) on gliclazide transport into bacterial cells. Materials and Methods: Probiotics were incubated with gliclazide with or without DCA for 24 h at 37°C. The intracellular and extracellular concentrations of gliclazide were determined at seven time points by high-performance liquid chromatography. Gliclazide biotransformation by the enzymatic activity of probiotic bacteria was examined using appropriate software packages. Results: During the 24 h incubation with probiotic bacteria, significantly lower extracellular concentrations of gliclazide were observed at all time points compared to controls, while in the group with DCA, the decrease in concentration was noticed only at 24 h. The total concentration of gliclazide throughout the whole period was significantly lower compared to control. Proposed pathways of gliclazide biotransformation by probiotic bacteria involve reactions of hydrolysis and hydroxylation. Conclusion: Based on the results obtained, it can be concluded that there are interactions of gliclazide-probiotics-DCA, at both the level of active and passive transport into the cells, and at the level of drug biotransformation by enzymatic activity of probiotic bacteria. The effect of these interactions on the final therapeutic response of gliclazide should be further studied and confirmed in in vivo conditions.

Introduction The aim of our study was to compare the level of the most common organophosphate metabolite, dimethyl phosphate, in urine of women giving birth to both boys with cryptorchidism (study group), and healthy boys (control group), as well as to compare the level of dimethyl phosphate in our population with the results obtained in other populations. Material and methods After the ethical approval we included thirty women in both study and control groups. All newborns were born between 38 and 42weeks' gestation. Urine samples were taken on 3rd postpartal day. Gas chromatography with flame photometric detection was used to analyze dimethyl phosphate in urine following the method of Wu et al. Statistical analysis was done using Mann–Whitney test to compare the results in the two groups. Results Geometric mean of dimethyl phosphate in the study group was 7.18±8.26μg/L and the creatinine-corrected level was 5.63±5.95μg/L, and in the control group, the values are 7.98±6.75μg/L and 6.15±7.01μg/L, respectively. There was not a statistically significant difference in levels of dimethyl phosphate between these two groups ( p =0.72786). Dimethyl phosphate levels obtained in similar studies are: 14.4μg/L in Israel, 3.7μg/L in Palestine, 10.3μg/L in Jerusalem, 1.60μg/L in Caribbean islands and 2.60μg/L in Canada. Conclusions Pregnant women in our country are exposed to organophosphate pesticides, but a correlation between the exposure to organophosphate pesticides and cryptorchidism was not found. Level of evidence I. Type of study : Prognostic study, prospective study.

Binary polymeric amorphous carvedilol solid dispersions were prepared using solvent method by varying solvent type, polymer type and carvedilol to polymer ratio in order to assess the influence of these factors and maximize carvedilol dissolution rate. Low and high molecular weight polyvinylpyrrolidone, polyvinylpyrrolidone-vinyl acetate copolymer and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer were used as polymeric carriers in carvedilol to polymer ratios 1:1, 1:2 or 1:4, while absolute ethanol or acetone were used as solvents. Hard gelatin capsules were prepared with carvedilol solid dispersion and lactose monohydrate, mannitol or microcrystalline cellulose. FTIR and PXRD were used to detect carvedilol crystallinity and identify carvedilol-polymer interactions and carvedilol polymorphs. These techniques confirmed carvedilol transition to amorphous state and suggested that hydrogen bonds were formed between carvedilol and polymer molecules. Carvedilol dissolution rate was significantly higher from solid dispersions with higher carvedilol to polymer ratio and solid dispersions prepared using the solvent in which the polymer was more soluble. Solid dispersion with polyvinylpyrrolidone-vinyl acetate copolymer in 1:4 ratio in absolute ethanol displayed the highest carvedilol dissolution rate with 91.78% carvedilol dissolved in the first 30 min. Capsules prepared with the selected solid dispersion and microcrystalline cellulose as diluent displayed the highest carvedilol dissolution rate, with 93.43% carvedilol dissolved within the first 30 min. Carvedilol bioavailability was significantly increased by formulating solid dispersions, while the analysis of serum biochemical parameters excluded damage on liver and kidney function and the lipid profile of animals exposed to investigated drug delivery system.

Introduction: Rosemary essential oil can be used for treating dyspepsia, mild spasmodic disorders of thegastrointestinal tract, externally as analgetic in muscular and articular pain and minor peripheral circulatory disorders.It is important to explore its analgesic potential and its influence on the pharmacodynamic and pharmacokineticproperties of paracetamol. Methodology: Rosemary essential oil was applied to mice orally (doses: 10 and 20 mg/kgb.w.) for pharmacodynamic tests for seven days. Rats treated with rosemary essential oil for seven days orally (5 and10 mg/kg b.w.) were used for the examination of the influence of essential oil on the pharmacokinetic properties ofparacetamol (applied on the 7th day p.o. or i.v.). Pharmacokinetic parameters were analyzed in blood samples obtainedfrom rats' tail veins, with the HPLC method. Results: The essential oil of rosemary shows analgetic properties. Therosemary essential oil increases pharmacological effects of paracetamol and does not change paracetamolbioavailability. Conclusion: The herbal drugs could change the pharmacodynamic and the pharmacokinetic propertiesof classical drugs and they could also change the safety of classical drugs use in human population.

Background/Aim. Hypertension is one of the leading causes of cardiovascular morbidity and mortality and more than a half of all health insurance expenditures for reimbursed medicines are allocated to antihypertensive drugs in Serbia. The aim of this study was to identify the antihypertensive drug utilization patterns among hypertensive outpatients in the city of Novi Sad, Serbia, determine the adherence to clinical guidelines and address the economic aspects of current prescribing practices. Methods. This retrospective observational study was conducted in Novi Sad over a period of six months. The data on the number of packages, size of packages, and retail price of antihypertensives issued on prescription in outpatients with the diagnosis of essential arterial hypertension was collected from all state-owned pharmacies in Novi Sad. Drug consumption was analyzed using the Anatomical Therapeutic Chemical (ATC)/defined daily dose (DDD) methodology. Results. Total consumption of antihypertensives issued on prescription over 6 month period in the city of Novi sad, Serbia was 283,48 DDD per 1,000 inhabitans per day (DID). Angiotensin converting enzyme inhibitors (ACEi) were most commonly prescribed drugs, and were used 3 times more often than calcium channel blockers and 5 times more than betablockers. The consumption of diuretics and angiotensin receptor antagonists was low within all groups of outpatients. Both national and international guidelines state superiority and effectiveness of diuretics in treatment of hypertension in the elderly, but their consumption was unreasonable low despite the fact that over 70% of all antihypertensive drugs in the city of Novi Sad were dispensed in people aged > 60. The use of more expensive ACEi was observed, despite the guidelines deeming all the drugs of these class equally effective in treatment of hypertension. Conclusion. Large differences in utilization of different groups of antihypertensive agents were noted in this study. Underutilization of valuable, efficacious, and cost-effective thiazide diuretics and over use of expensive ACE inhibitors is unjustifiable. There is a potential for large savings with switching to low-price ACEi, modeling the practice of Scandinavian countries. [Projekat Ministarstva nauke Republike Srbije, br. III 41012]

Aniseed (Pimpinella anisum L., Apiaceae) and its essential oil (EO) have been widely used. Because there are some data about the impact of aniseed EO on drug effects, this survey aimed to assess the potential of pharmacokinetic herb-drug interaction between aniseed EO and acetaminophen and caffeine in mice. The chemical analysis (gas chromatography-mass spectrometry) of aniseed EO has confirmed trans-anethole (87.96%) as the main component. The pharmacokinetic studies of intraperitoneally (i.p.) and orally applied acetaminophen (200 mg/kg) and caffeine (20 mg/kg) were performed in mice after 5 days of oral treatment with human equivalent dose of aniseed EO (0.3 mg/kg/day). The analysis of pharmacokinetic data showed that in the group treated by aniseed EO, the significant decrease in the peak plasma concentration of acetaminophen after oral application (p = 0.024) was revealed when compared with control group and the reduction of systemic exposure to the drug after oral application (74 ± 32% vs. 85 ± 35% in the control) was noted. The bioavailability of orally applied caffeine was also significantly decreased (p = 0.022) after the EO treatment in comparison with the control (57 ± 24% vs. 101 ± 29%). Therefore, the compromised therapeutic efficacy of acetaminophen and caffeine during the usage of aniseed EO preparations should be considered.

Background/Aim. The overuse of antibiotics unnecessarily exposes patients to risk of side effects, encourages reconsultation for similar problems and enhances antimicrobial resistance. The use of antibiotics in the year 2011 in Montenegro was high (39.05 Defined Daily Dose ? DDD/1,000 inhabitants/day), but it was not considered in relation to the frequency of bacterial diseases. The aim of our study was to determine the degree of conformance between the amount of outpatient antibiotic consumption and the reported prevalence of outpatient bacterial infections in the Republic of Montenegro. Methods. Data on the use of antibacterial drugs was obtained from the Agency for Medicines and Medical Devices of Montenegro for the year 2012. The amount of antibiotics was calculated using the Anatomic Therapeutic Chemical (ATC) DDD methodology. Data on the prevalence of outpatient infective disease was obtained from the Health Statistical Yearbook 2012 of Montenegro and it was expressed per 1,000 inhabitants. Results. A total of 30.34 DDD/1,000 inhabitants/day of antibiotics in outpatients were prescribed in Montenegro in 2012, with penicillins being most frequently prescribed. Amoxicillin and amoxicillin with clavulanic acid were the most frequently used antibiotics. The prevalence of outpatient bacterial infections was 6,745 cases or 10.87/1,000. The most frequent infections were respiratory tract infections. Less than 50% of the prescribed amount of antibiotics were prescribed in accordance with national guidelines on treatment of bacterial infections. Conclusion. Use of antibiotics in Montenegro in 2012 was more than double than necessary according to prevalence of bacterial infections and average duration of treatment. The structure of antibiotics was not in full compliance with the national good practice guidelines, but it was in accordance with data on bacterial antibiotic resistance in outpatient practice. It is necessary to initiate measures to rationalize the use of antibiotics both in terms of quantity and in terms of the structure of the most used antibiotics.

Many forms of breast carcinoma are hormone-dependent and therefore development of novel aromatase inhibitors is of particular interest. Since brain metastases are frequent in patients with advanced breast carcinoma, one of the goals of modern drug development is the discovery of drugs with specific pharmacokinetic profile. High performance thin layer chromatography (HPTLC) is often used to determine lipophilicity of the molecules based on their retention constant. As a predictive analysis, multiple linear regression method was performed to connect pharmacokinetic-dependent parameters with independent physicochemical properties such are: RM0 , TPSA and Mw of fourteen D-ring modified oestrone derivatives. Additionally, docking studies were performed. Conducted correlation analysis indicates excellent dependence between experimental RM parameter values and calculated values of pharmacokinetic parameters. Results show sufficient intestinal absorption of all the investigated molecules as well as moderate volumes of distribution and strong affinity for binding to plasma proteins. Crossing blood-brain barrier is predicted to be successful for 11 compounds. The created quantitative structure activity relationship model represents an excellent predictive tool and enables determination of pharmacokinetic properties of examined compounds. Docking analysis defined molecules I3 and II3 to be the best candidates; however, compound II3 violates the Lipinski rule. It has been concluded that molecules with hydroxyl group at C-3 more effectively pass through blood-brain barrier while structures with benzyloxy groups have stronger interactions with CYP1A19. Molecules II2 , II4 , II6 , and II7 are regarded as most suitable candidates for further investigation considering their good pharmacokinetic and docking characteristics. Copyright © 2017 John Wiley & Sons, Ltd.

The aim is to evaluate the role of diazepam concentrations in development of low-concentration-methadone-associated QTc prolongation in patients with opioid use disorder during methadone maintenance treatment (MMT) induction.Individuals with addiction disorder on MMT were studied before the beginning of MMT and after one and six months of MMT. Serum concentrations of methadone, diazepam, electrolytes and ECG were analyzed.Thirty patients were enrolled. The mean methadone concentration at time points was 177 ± 119 ng/ml and 343 ± 182 ng/ml, while the mean diazepam concentration was 561 ± 437 ng/ml and 1045 ± 933 ng/ml. The QTc interval before the introduction of MMT, after 1 and 6 months of MMT were 412 ± 27 ms, 425 ± 18 ms and 424 ± 15 ms, respectively, showing statistically significant increase in the length of QTc interval after 1 and 6 months of MMT. Statistically significant correlation between the concentration of methadone and QTc interval length at observed time points (RThe prolongation of QTc below the risk threshold in low methadone therapeutic doses has been recorded and concomitant use of diazepam could be a co-factor in such issue.

The dried blood spot (DBS), a sample of filter paper bearing dried blood, has been applied in the field of clinical chemistry and pharmaceutical industry, for detection of different diseases and for drug development. This paper presents electrical characterization of DBS samples with different concentrations of a chemotherapy agent — drug methotrexate (MTX). Experimental characterization was conducted using a Hall-effect measurement system, profilometer, and impedance analyzer. Obtained results revealed that mobility decreases and resistivity increases with an increase of MTX concentration in DBS samples.

Herb-drug interactions are an important safety concern and this study was conducted regarding the interaction between the natural top-selling antidepressant remedy Hypericum perforatum (Hypericaceae) and conventional drugs. This study examined the influence of acute pretreatment with different extracts of Hypericum perforatum from Serbia on pentobarbital-induced sleeping time, impairment of motor coordination caused by diazepam and paracetamol pharmacokinetics in mice. Ethanolic extract, aqueous extract, infusion, tablet and capsule of Hypericum perforatum were used in this experiment. The profile of Hypericum perforatum extracts as well as paracetamol plasma concentration was determined using RP-HPLC analysis. By quantitative HPLC analysis of active principles, it has been proven that Hypericum perforatum ethanolic extract has the largest content of naphtodianthrones: hypericin (57.77 µg/mL) and pseudohypericin (155.38 µg/mL). Pretreatment with ethanolic extract of Hypericum perforatum potentiated the hypnotic effect of pentobarbital and impairment of motor coordination caused by diazepam to the greatest extent and also increased paracetamol plasma concentration in comparison to the control group. These results were in correlation with naphtodianthrone concentrations. The obtained results have shown a considerable influence of Hypericum perforatum on pentobarbital and diazepam pharmacodynamics and paracetamol pharmacokinetics.

Background/Aim. It is known that bile acids improve the absorption, bioavailability and pharmacodynamic characteristics of some drugs. Morphine analgesia is produced by activation of opioid receptors within the central nervous system (CNS) at both spinal and supraspinal levels. Since a morphine molecule contains 3 polar groups and therefore hard to transfer through the blood-brain barrier, the aim of the study was to examine the potential influence of bile acids derivates, namely sodium salt of monoketocholic acid (MKH-Na) and methyl ester of monoketocholic acid (MKH-Me), on analgesic effect of morphine. Methods. White male mice of NMRI-Haan strain, with body weight of 20-24 g, were used in this study. The analgesic effect of morphine (administered by subcutaneous and intramuscular route in a dose of 2 mg/kg), with and without pretreatment with MKH-Na (4 mg/kg) and MKH-Me (4 mg/kg) was estimated by the hot plate method. Results. Administration of MKH-Me prior to subcutaneous administration of morphine increased the morphine analgesic effect but the increase was not statistically significant. At the same time administration of MKH-Na did not affect morphine analgesic effect. The analgesic effect of morphine increased when administered intramuscularly 20 min after MKH-Me administration. When compared with the group of animals treated only with morphine, a statistically significant increase in analgesic effect was detected 10, 30, 40 and 50 min after morphine administration (p < 0.05). Pretreatment with MKH-Na did not affect morphine analgesic effect. Conclusion. According to the results of this study it can be presumed that after intramuscular morphine administration methyl ester of monoketocholic acid increases morphine transport into the central nervous system and consequently the analgesic effect, as well. Further research on bile acids-morphine interaction both in vitro and in vivo is necessary to completely elucidate the mechanism of this interaction and increase in the morphine analgesic effect. [Projekat Ministarstva nauke Republike Srbije, br. 41012: Interactions of xenobiotics and the impact on biomedical system i br. 172050: Development and application of advanced chromatographic and spectroscopic techniques in analysing xenobiotics and the mechanisms of their decomposition in biotic and abiotic samples]

Aim: The aim of this study is to investigate the influence of bile salts, sodium cholate, sodium 12-ketocholate and sodium dehydrocholate, as excipients in ranitidine, aminophylline and phenobarbital tablets on dissolution rate. Methods: Four groups of tablets (control without bile salts and three investigational groups containing different bile salts) were prepared for three different drug substances: ranitidine, aminophylline and phenobarbital. Dissolution rate was measured. Results: Dissolution rate is increased significantly in all investigational groups comparing to the control group in all three drug substances. Discussion: Presented results are very favourable and encouraging in case of dissolution enhancing and should be further investigated, especially in drug substances that are classified in class II and IV as per Biopharmaceutical Classification System (BCS) classification. Conclusion: Bile acid salts are very promising excipients, proven to act as surfactants and as lubricants. Running title: Bile salts as excipients in ranitidine, aminophylline and phenobarbital tablets.

Diabetes mellitus is a chronic disease characterized by abnormal carbohydrate, lipid and protein metabolism due to a lack of insulin or reduced target cell sensitivity to insulin. Stevia rebaudiana is an important source of biochemically active substances with proven anti-diabetic effect. The aim of this study was to determine anti-diabetic effects of the low dose of stevioside in NMRI Haan mice. Aqueous stevioside solution (20mg/kg body weight) was administered by oral route of administration. Anti-diabetic effect of stevioside was estimated by oral glucose tolerance test, adrenaline test after a 10day stevioside treatment, and alloxan induced hyperglycaemia in mice (two experimental groups, 10day stevioside treatment before and after alloxan administration). Aqueous stevioside solution prevented significant increase in glycaemia in oral glucose tolerance test (9.22±1.13 to 9.85±1.32mmol/l, P

Purpose: Animal tests have been often used in toxicology to determine parameters describing toxicity of a particular substance. However, in vivo tests must fulfill ethical requirements, and are both time and money consuming. Therefore, computational methods are considered to be very useful in toxicity prediction. Methods: Retention parameters were acquired by normal-phase TLC. Lipophilicity was used as a key parameter for predicting toxic potential. The correlation coefficients between calculated log P values obtained by five different software and experimentally determined hydrophobicity parameters ((tol/et), (tol/but), b(tol/et) and b(tol/but)) were calculated. Results: Correlation analysis provided reliable information (r2 > 0,8) for aquatic species – minnow, medaka, daphnia, and algae. In addition valuable data regarding rodents and AMES test were obtained. Conclusions: Tested bile acids show relatively good toxicological properties. Less toxic effects are noticed in compounds with higher pola...

Aims The current treatment of Alzheimer's disease is purely symptomatic. Scientists are looking for new treatment options which could alter the course of the disease and improve the quality of life in patients with Alzheimer's disease. In this paper 14 novel s-triazine molecules have been evaluated for their lipophilicity. In addition docking study was carried out to evaluate acetylcholinesterase activity of these compounds. Main methods Lipophilicity was evaluated by RP HPTLC using 5 different mobile phases and obtained results were used in calculations of pharmacokinetic parameters - logBB, Ka and Pej. Multiple linear regression analysis was refined, taking account of molecular polarity (total polar surface area, TPSA) and molecular weight (Mw) descriptors. Appropriate QSAR models were developed. Docking studies were carried out using the Vina docking. Key findings Five out of fourteen compounds evaluated [5-10] are selected as the most promising compounds with satisfactory pharmacokinetic properties and good docking scores. Significance Compound 10 possesses the best combination of favourable pharmacokinetic characteristics (brain penetration, intestinal absorption) and capacity for acetylcholinesterase inhibition. Consequently this molecule should be further evaluated for potential therapeutic use in Alzheimer's disease.

Silymarin is a complex of five major compounds, and silibinin is the most biologically active component of the complex. The aim of this study was to investigate, evaluate and confirm the potential cardioprotective and hepatoprotective effects of administration of silymarin, rich in silibinin, at a dose of 60 mg/kg orally for a time-span of 12 days on doxorubicin induced toxicity in male Wistar rats. The in vivo model was used to explore whether silymarin could prevent damage of liver and heart tissue induced by doxorubicin administered every other day at dose of 1.66 mg/kg intraperitoneally for twelve days. In the study the change of body weight, ECG changes, biochemical parameters of oxidative stress, serum activity of alanine and aspartate transaminase, lactate dehydrogenase, creatine kinase and histological preparations of heart and liver samples of treated animals were examined. According to physiological, pharmacological, microscopic and biochemical results, we confirmed that at the examined dose, silymarin exhibits a protective influence on the heart and liver tissue against toxicity induced by doxorubicin.

The pharmacodynamic effect of a 7-day oral treatment with a suspension of Coprinus comatus at doses of 0.835 and 1.670 g/kg in rats was studied. Changes in body weight, bile secretion and hypoglycaemic action were examined together with antipyretic activity and paw oedema tests. Such treatments resulted in a significantly lower increase in the body weight of tested animals (15.73 ± 8.36 g/rat in the untreated group, 8.44 ± 8.23 g/rat (p < 0.05) and 3.18 ± 7.93 g/rat (p < 0.05), for C. comatus 0.835 and 1.67 g/kg, respectively). Hypoglycaemic action was evident only in the glucose load test (6.79 ± 0.61 to 9.70 ± 1.16 (p < 0.05) in the untreated group and 6.47 ± 0.35 to 7.27 ± 0.76 for C. comatus 1.67 g/kg). Histological examination of pancreas cross-sections suggested certain protective functions of the mushroom suspension in alloxan poisoning. In the antipyretic test, a significantly lower increase in body temperature was observed in the mushroom-pretreated rats. In the paw oedema test, no decrease in oedema induced by formalin injection was observed following treatment with C. comatus.

Purpose Information on ADME properties of examined bile acids and their oxo derivatives are scarce, although the interest for bile acids and their use in nanochemistry and macromolecular chemistry is increasing. The purpose of this research was to evaluate the lipophilicity, a crucial physicochemical parameter for describing ADME properties of selected bile acids and their oxo derivatives, and to compare two approaches: experimentally determined hydrophobicity parameters and calculated log P values. Methods Commercially available bile acids - deoxycholic, chenodeoxycholic, hyodeoxycholic and ursodeoxycholic acid were used to synthesize oxo derivatives. Lipophilicity was evaluated in two solvent systems: toluene/ethanol and toluene/butanol. Retention parameters were acquired by normal-phase TLC. The correlations between calculated log P values obtained using five different software and experimentally determined hydrophobicity parameters ( R M 0 (tol/eth) , R M 0 (tol/but) , b (tol/eth) and b (tol/but) ) were examined. Results Correlation analysis confirmed significant dependence between experimental R M 0 values and software calculated parameters. Results suggest satisfactory intestinal absorption after oral administration for all of the examined compounds as well as low volumes of distribution, and high affinity for binding with plasma proteins. Penetration through blood-brain barrier and skin is not satisfactory. All of the examined compounds show high affinity for binding with G-protein coupled receptors and consequently inhibition of ionic channels. Results also suggest possible binding with nuclear receptors. Conclusions Established lipophilicity testing model of studied compounds showed excellent predictive ability and might represent significant tool in development of relations between chromatographic behavior and ADME properties. Compounds 3α-hydroxy-7,12-dioxo-5β-cholanoic and 12α-hydroxy-3,7-dioxo-5β-cholanoic acid might be the most suitable candidates for further development studies (satisfactory pharmacokinetic properties and lowest haemolytic potential) followed by 3α-hydroxy-12-oxo-5β-cholanoic acid and 3α-hydroxy-7-oxo-5β-cholanoic acid (slightly higher haemolytic potential, but better ligand properties).

Matricaria recutita L. (Asteraceae) is one of the most ancient medical herbs, although the therapeutic uses and health benefits of chamomile are based largely on tradition. The present study aimed to investigate the effects of chamomile extract on the intestinal motility. Due to the fact that preparation techniques could significantly alter the glucoside content in the chamomile, we also explored the possible differences in the effects on gastrointestinal motility between native and fermented chamomile extract. Thirty minutes after the administration of saline or chamomile ligulate flower extracts, all animals were orally administered charcoal meal by gavage (0.6 ml emulsion–0.4 g Carbo medicinalis and 0.2 g Gummi arabicum in 10 ml of olive oil). Animals were sacrificed by cervical dislocation 30 min after charcoal meal administration. Intestinal motility was estimated according to the distance between Carbo medicinalis and pylorus in centimeters. Both native and fermented extract decreased intestinal motility compared to control. Native chamomile extract (5 mg/kg) and fermented chamomile extract (2.5 mg/kg) significantly decreased intestinal motility compared to control group (NE5=27.41±2.79, P

Introduction: Distribution coefficient (D) is useful parameter for evaluating drugs permeability properties across biological membranes, which are of importance for drugs bioavailability. Given that bile acids are intensively studied as drug permeation-modifying and -solubilizing agents, the aim of this study was to estimate the influence of sodium salts of cholic (CA), deoxycholic (DCA) and 12-monoketocholic acids (MKC) on distribution coefficient of simvastatin (SV) (lactone [SVL] and acid form [SVA]) which is a highly lipophilic compound with extremely low water solubility and bioavailability.Methods: LogD values of SVA and SVL with or without bile salts were measured by liquid-liquid extraction in n-octanol/buffer systems at pH 5 and 7.4. SV concentrations in aqueous phase were determined by HPLC-DAD. Chem3D Ultra program was applied for computation of physico-chemical properties of analyzed compounds and their complexes.Results: Statistically significant decrease in both SVA and SVL logD was observed for all three studied bile salts at both selected pH. MKC exerted the most pronounced effect in the case of SVA while there were no statistically significant differences between observed bile salts for SVL. The calculated physico-chemical properties of analyzed compounds and their complexes supported experimental results.Conclusions: Our data indicate that the addition of bile salts into the n-octanol/buffer system decreases the values of SV distribution coefficient at both studied pH values. This may be the result of the formation of hydrophilic complexes increasing the solubility of SV that could consequently impact the pharmacokinetic parameters of SV and the final drug response in patients.

Aniseed (Pimpinella anisum L., Apiaceae) and its essential oil (EO) have been widely used. Because there are some data about the impact of aniseed EO on drug effects, this survey aimed to assess the potential of pharmacokinetic herb-drug interaction between aniseed EO and acetaminophen and caffeine in mice. The chemical analysis (gas chromatography-mass spectrometry) of aniseed EO has confirmed trans-anethole (87.96%) as the main component. The pharmacokinetic studies of intraperitoneally (i.p.) and orally applied acetaminophen (200 mg/kg) and caffeine (20 mg/kg) were performed in mice after 5 days of oral treatment with human equivalent dose of aniseed EO (0.3 mg/kg/day). The analysis of pharmacokinetic data showed that in the group treated by aniseed EO, the significant decrease in the peak plasma concentration of acetaminophen after oral application (p = 0.024) was revealed when compared with control group and the reduction of systemic exposure to the drug after oral application (74 ± 32% vs. 85 ± 35% in the control) was noted. The bioavailability of orally applied caffeine was also significantly decreased (p = 0.022) after the EO treatment in comparison with the control (57 ± 24% vs. 101 ± 29%). Therefore, the compromised therapeutic efficacy of acetaminophen and caffeine during the usage of aniseed EO preparations should be considered.