Comparative Pharmacokinetic and Pharmacodynamic Properties of Oral and Intravenous (+)-Sotalol in Healthy Volunteers

Abstract— The pharmacokinetic and pharmacodynamic properties of (+)-sotalol (BMY-5763) were studied to analyse the relationship between plasma concentration and QT_c prolongation in healthy male volunteers given single oral doses of 50, 100, 200 and 300 mg, repeated oral doses of 200 mg twice daily for 6·5 days, and single intravenous doses of 1·0 and 1·5 mg kg^?1. The plasma concentration of (+)-sotalol peaked about 3 h after oral administration and declined with a half-life of 7·9–9·7 h. The C_max and AUC showed dose-related increases, while the urinary recovery as the unchanged form remained constant (66–68% of the dose). During repeated oral administration the plasma concentration of (+)-sotalol reached almost a steady state on the 3rd day and there was no change in renal clearance of (+)-sotalol measured on the 1st, 4th and 7th days. After intravenous administration, (+)-sotalol in plasma decreased biexponentially with a terminal half-life of 7·6–8·3 h and the urinary recovery as unchanged drug amounted to 84–88% of the dose. The increase in QT interval was significant after a single oral administration except for the lowest dose, and regression analysis revealed a significant correlation between QT_c interval and concentration of (+)-sotalol in plasma. The same correlation was evident with repeated oral doses on the 1st, 4th and 7th days. In the case of single intravenous administrations of (+)-sotalol, a combined pharmacokinetic-pharmacodynamic model was attempted by assuming an effect compartment. This analysis was shown to be effective to adjust the lag of effect behind a rapid change in plasma concentration which occurred in the early distributive phase because there was no evidence that the metabolite made any significant contribution to the effect of (+)-sotalol.     

单次和多次口服氯乙酰左卡尼汀片在健康人体的药动学研究

目的 采用LC-MS/MS测定人血浆中乙酰左卡尼汀的浓度并用于氯乙酰左卡尼汀片在健康受试者体内的药动学研究。方法 健康受试者单次给药0.5,1.0,1.5 g和多次给予0.5 g后,0~24 h采集血样。通过测定单次和多次给药后血浆中乙酰左卡尼汀的绝对浓度,计算其药动学参数。米屈肼为内标,经甲醇沉淀蛋白后进行LC-MS/MS分析。ESI离子源正离子模式监测,检测离子m/z 204.3→145.2（乙酰左卡尼汀）,m/z 147.2→58.2（米屈肼）;色谱柱为EC 250/4.6 NUCLEOSIL100-5CN,流动相为甲醇-10 mmol·L^-1乙酸铵溶液（含0.1%甲酸）（85：15）。结果 乙酰左卡尼汀在20~3 000 μg·L^-1内线性良好（r=0.999 1）,最低定量限为20 μg·L^-1。批内、批间精密度及基质效应RSD均<15%。单次给药3个剂量组（0.5,1.0,1.5 g）的主要药动学参数为：AUC_0-t为（4 181.77±2 473.24）μg·h·L^-1、（6 099.54±1 939.41）μg·h·L^-1和（8 064.71±3 575.99）μg·h·L^-1,C_max为（611.42±270.76）μg·L^-1,（830.92±233.19）μg·L^-1和（1 004.67±414.95）μg·L^-1,t_1/2z为（4.50±2.93）h、（6.25±3.65）h和（5.76±3.94）h;多次给药后主要的药动学参数：AUC_0-t为（13 728.82±6 493.04）μg·h·L^-1,C_max为（1 129.00±374.05）μg·L^-1,t_1/2z为（8.57±4.42）h。结论 本方法准确、灵敏、专属性强,适用于人体内乙酰左卡尼汀药动学研究。单次和多次给予氯乙酰左卡尼汀片后药动学参数有明显差异,性别间无差异,健康受试者对药物的耐受性良好。     

The Absolute Oral Bioavailability and Population-Based Pharmacokinetic Modelling of a Novel Dipeptidylpeptidase-IV Inhibitor,Vildagliptin, in Healthy Volunteers

BACKGROUND AND OBJECTIVE: Vildagliptin is a potent, selective, orally active inhibitor of dipeptidylpeptidase-IV being developed for the treatment of type 2 diabetes mellitus. The objective of this study was to assess the absolute oral bioavailability of vildagliptin by comparing the systemic exposure after oral and intravenous administration in healthy volunteers. METHODS: This was an open-label, randomised, two-period, two-treatment, crossover study in 11 healthy volunteers. Subjects received vildagliptin 50mg orally or 25mg as a 30-minute intravenous infusion on two occasions separated by a 72-hour washout period. Vildagliptin concentrations were determined by a specific assay in urine (lower limit of quantification [LLQ] = 5 ng/mL) and serial plasma samples (LLQ = 2 ng/mL) obtained up to 24 hours after dosing. Noncompartmental analysis and population pharmacokinetic modelling were performed. RESULTS: Both noncompartmental analysis and population pharmacokinetic modelling estimated the absolute oral bioavailability of vildagliptin to be 85%. Renal elimination of unchanged vildagliptin accounted for 33% and 21% of the administered dose 24 hours after intravenous and oral administration, respectively. Renal clearance (13 L/h) was approximately one-third of the total systemic clearance (41 L/h). Two peaks were observed in plasma concentrations at 1 and 3 hours after oral administration in nine of 11 subjects. Modelling based on the population approach identified two absorption sites with lag-times of 0.225 and 2.46 hours. Both absorption rate constants were slower than the elimination rate constant, indicating 'flip-flop' kinetics after oral administration. Bodyweight was identified as a factor with an impact on the volume of distribution of the peripheral compartment. Clearance was 24% greater in males (44.6 L/h) than in females (36.1 L/h). CONCLUSIONS: Vildagliptin is rapidly and well absorbed with an estimated absolute bioavailability of 85%. Two possible sites of absorption were identified, and the absorption rates were slower than the elimination rate, indicating a flip-flop phenomenon after oral dosing.     

Pharmacokinetic Analysis of Mizolastine in Healthy Young Volunteers After Single Oral and Intravenous Doses: Noncompartmental Approach and Compartmental Modeling

This paper presents the analysis of the kinetics of a new antihistamine, mizolastine, in 18 healthy volunteers, from concentrations measured after an intravenous infusion and two different oral administrations: tablet and capsule. Two approaches were used to analyze these data: (i) a noncompartmental approach implemented in PHARM-NCA: (ii) a compartmental modeling approach implemented in a new S-PLUS library. NLS2, ⁵ which allows the estimation of variance parameters simultaneously with the kinetic parameters. For the compartmental modeling approach, two-compartment open models were used. According to the Akaike criterion, the best model describing the kinetics of mizolastine after oral administration was the zero-order absorption model. The kinetic parameters obtained with PHARM-NCA and NLS2 were similar. The estimated duration of absorption was greater for the tablets than for the capsules (with means equal to 1.13 hr and 0.84 hr respectively). After an intravenous infusion, the mean estimated clearance was 4.9 L/hr, the mean ₂ -phase apparent volume of distribution was 89.6 L and the mean terminal half-life was 12.9 hr.     

Evaluation of the Safety,Tolerability, and Pharmacokinetic Profiles of TP0473292 (TS-161), A Prodrug of a Novel Orthosteric mGlu2/3 Receptor Antagonist TP0178894, in Healthy Subjects and Its Antidepressant-Like Effects in Rodents

BackgroundTP0473292 (the active ingredient of TS-161) is a prodrug of a novel metabotropic glutamate (mGlu) 2/3 receptor antagonist being developed for the treatment of patients with depression. This study evaluated the safety, tolerability, and pharmacokinetics of orally administered TS-161 in healthy subjects.MethodsThis was a first-in-human, phase 1, randomized, double-blind, placebo-controlled, single-ascending dose (15–400 mg TS-161) and 10-day multiple-ascending dose (50–150 mg TS-161) study in healthy subjects, conducted from June 2019 through February 2020. Plasma and urine concentrations of the prodrug and its metabolites, and cerebrospinal fluid (CSF) concentrations of the active metabolite TP0178894 were measured to evaluate the pharmacokinetic profiles after oral administration of TS-161.ResultsFollowing single and multiple doses, TP0473292 was extensively converted into its active metabolite TP0178894. Plasma concentrations of TP0178894 reached peak (C_max) within 5 hours post dose and declined with a t_1/2 <13 hours. Plasma exposures of TP0178894 increased with increasing dose. TP0178894 penetrated into CSF and reached a C_max of 9.892 ng/mL at a single dose of 100 mg, which was comparable with IC₅₀ values of antagonist activity at mGlu2/3 receptors. The most frequently observed adverse events that showed exposure-related incidence during the study were nausea, vomiting, and dizziness.ConclusionsThe mGlu2/3 receptor antagonist prodrug TP0473292 is safe and well-tolerated, is orally bioavailable in humans with extensive conversion into the active metabolite TP0178894 with sufficient CSF penetration to exert the anticipated pharmacological effects, and is a promising candidate for further clinical development in treatment of patients with depression.     

Pharmacokinetics,Safety and Tolerability of Bencycloquidium Bromide,a Novel Selective Muscarinic M1/M3 Receptor Antagonist,After Single and Multiple Intranasal Doses in Healthy Chinese Subjects: An Open-Label,Single-Center,First-in-Human Study

Background: Bencycloquidium bromide (BCQB) is a novel, potent and selective muscarinic M1/M3 receptor antagonist under development for the treatment of rhinorrhea in rhinitis. The pharmacokinetics and safety of BCQB in animals have been established in preclinical studies. However, no clinical pharmacokinetic data are available for BCQB in humans.Objective: The aim of this first-in-human study was to evaluate the pharmacokinetics, safety and tolerability of BCQB following single and multiple intranasal doses in healthy Chinese subjects.Methods: The clinical trial was comprised of the following four studies: (i) an open-label, single-dose escalation study to evaluate the safety and tolerability in healthy subjects after intranasal doses of BCQB ranging from 45 to 450 mg (total of six doses); (ii) an open-label, multiple-dose escalation study to assess the safety and tolerability in healthy subjects after intranasal administration with 120 and 150 mg doses of BCQB (360 and 450 μg/day) administered three times daily for 15 days; (iii) a randomized, open-label and parallel-group design to evaluate the single-dose pharmacokinetics of BCQB after intranasal dosing (45, 90, and 180 μg); and (iv) ten subjects received 120 μg of BCQB by intranasal administration, three times daily for 5 days with a final single dose on day 7 to assess its multiple-dose pharmacokinetics. Safety and tolerability of BCQB were evaluated by monitoring adverse events (AEs), ECG recordings, vital signs and clinical laboratory parameters. The pharmacokinetic parameters for BCQB were calculated by software using noncompartmental methods.Results: All AEs were mild, of limited duration and no more frequent at higher doses. There was no serious adverse event, death or withdrawal. No clinically significant change was noted in clinical laboratory parameters, cardiac parameters or vital signs. Following single intranasal dosing, BCQB was rapidly absorbed with a median time to maximum concentration (t_max) of 8 minutes for 45, 90, and 180 mg dose groups; the plasma concentration of BCQB decreased in a biphasic manner with the mean half-life (t_1/2) of 8.5 hours; the maximum concentration (C_max) and area under the plasma concentration-time curve (AUC) of BCQB increased linearly across the examined dose range of 45–180 μg. During the multiple dosing, the steady state was achieved within 3 days of 120 μg three times daily dosing of BCQB. A slightly greater AUC was observed after 5 days of multiple dosing, with the mean accumulation ratio of 1.26; however, the half-life was unchanged.Conclusion: BCQB was safe and well tolerated in healthy Chinese subjects when administered intranasally with single and multiple doses across the doses studied. The mean C_max and AUC increased proportionally to the studied doses, and the steady state was achieved within 3 days after three times daily dosing. A slight accumulation of BCQB following multiple dosing was observed. The pharmacokinetics, safety and tolerability profiles of BCQB pose it as a good candidate for further development in the treatment of rhinorrhea in rhinitis.     

The Use of Roxifiban (DMP754), a Novel Oral Platelet Glycoprotein IIb/IIIa Receptor Inhibitor, in Patients with Stable Coronary Artery Disease

Methods

Ninety-eight patients were randomized to receive either a placebo or 1 of 8 oral dosages of roxifiban. Twenty-two patients were enrolled in multiple-dose regimens, bringing the total study population to 120. The oral dosages were 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, or 2.5 mg/day for up to 30 days.

Results

Pharmacodynamic response of roxifiban was clearly dose-dependent. Platelet aggregation inhibition in response to 10 μmol/L slope adenosine diphosphate was sustained throughout the study period (up to 1 month). No serious adverse events, including significant major bleeding events, were associated with roxifiban treatment. Minor bleeding was reported in 5% of participants in the placebo group (1 of 21 cases) versus 26% in the study group (26 of 99 cases). Incidence of minor bleeding associated with roxifiban 2 and 2.5 mg/day was significantly (p ≤ 0.05) greater than that with placebo. Adverse events, including gastrointestinal disorders, platelet and clotting disorders, and urinary tract disorders, were observed in 1 of 21 cases (5%) in the placebo group and in 12 of 99 cases (12%) in the study group. Reversible thrombocytopenia without other complications developed in two patients.

Conclusions

Roxifiban-induced inhibition of platelet aggregation was dose-dependent and sustained throughout the study period: higher drug dosages correlated with higher levels of platelet inhibition and higher incidence of minor bleeding events. No serious adverse events were observed at any dosage. Thus, roxifiban appears to be a potent oral platelet GP IIb/IIIa receptor inhibitor that is clinically well-tolerated and deserves further study as a new treatment strategy in patients with chronic stable angina pectoris.     

Pharmacodynamic and Pharmacokinetic Studies in Rats of S-8-(2-Furyl)- and R-8-Phenyl-2-(di-n-Propylamino)Tetralin,Two Novel 5-HT1A Receptor Agonists In-vitro with Different Properties In-vivo

R- and S-8-(2-Furyl)- and R- and S-8-phenyl-2-(di-n-propylamino)tetralins (R- and S-LY-55 and R- and S-LY-49, respectively), novel enantiopure dipropylaminotetralins, have been screened as 5-HT_1A receptor ligands. All had nanomolar affinities for 5-HT_1A receptors and fully inhibited forskolin-stimulated adenylyl cyclase in-vitro (i.e. the four compounds appeared to be 5-HT_1A agonists). It was also found that the enantiomers of LY-55 behaved as typical 5-HT_1A receptor agonists in rats in-vivo by inducing a typical behavioural 5-HT syndrome, hypothermia and a decrease in 5-HT synthesis and turnover, indicating effects both on postsynaptic 5-HT_1A receptors and somatodendritic 5-HT_1A autoreceptors. In contrast, R- and S-LY-49 did not cause any 5-HT_1A receptor-related effects in-vivo except for a partial inhibition of 5-HT synthesis after high doses. The 5-HT_1A receptor antagonist WAY-100635 was shown to attenuate the R-LY-49-induced inhibition of 5-HT synthesis, indicating the compound to be a weak agonist at somatodendritic 5-HT_1A autoreceptors. R-LY-49 at a high dose and with a long pre-treatment time interval inhibited the hypothermic and behavioural effects, but not the inhibition of 5-HT synthesis induced by the 5-HT_1A receptor agonist R-8-hydroxy-(dipropylamino)tetralin (R-8-OH-DPAT). Taken together, these findings seem to indicate, that R-LY-49 is a weak partial agonist at 5-HT_1A receptors. A comparative pharmacokinetic study showed that the enantiomers of LY-55 entered the brain rapidly after subcutaneous administration and reached peak brain tissue/plasma concentration ratios within 15–30 min of injection, whereas the brain concentrations of R-LY-49 increased slowly, reaching a relatively low peak brain tissue/plasma concentration ratio 90 min after injection despite their similar lipophilicity. The differences between the pharmacological activity of the two compounds in-vivo seem to be explained by their different abilities to cross the blood-brain barrier, and a weak agonistic activity of R-LY-49 on 5-HT_1A receptors, both pre- and postsynaptically, compared with S-LY-55. Further studies are, however, needed for a deeper understanding of these differences.     

ATP-Dependent Transport of a Novel Thromboxane A2 Receptor Antagonist, [2-(4-Chlorophenylsulfonylaminomethyl)-Indan-5-yl]Acetate (Z-335) and Its Xenobiotic Taurine Conjugate (Z-335-Tau) by Rat Bile Canalicular Membrane Vesicles

PURPOSE: The characteristics of bile canalicular transport processes for xenobiotic taurine conjugates have not yet been clarified. To elucidate the biliary excretion characteristics of xenobiotic taurine conjugates, we investigated the transport of a novel thromboxane A2 receptor antagonist, Z-335, and its taurine conjugate (Z-335-Tau) across the bile canalicular membrane. METHODS: We examined the uptake of Z-335 and Z-335-Tau by isolated bile canalicular membrane vesicles (CMVs) from Sprague Dawley and Eisai-hyperbilirubinemic rats (EHBRs) which EHBRs have a hereditary defect of canalicular multidrug resistance-associated protein 2 (Mrp2) function. Also, the in vitro and in vivo kinetics of Z-335-Tau uptake and excretion were compared. RESULTS: Z-335 uptake by CMVs from normal rats exhibited marked ATP-dependence, whereas ATP-dependent uptake of Z-335 into CMVs from EHBRs was not observed. In contrast, Z-335-Tau uptake into CMVs from both normal rats and EHBRs was ATP dependent. The initial uptake velocity was concentration-dependent, with an in vitro Michaelis constant for initial uptake of 189 microM, which was similar to the in vivo value. CONCLUSIONS: The biliary excretion of Z-335 involves Mrp2, whereas that of Z-335-Tau involves active transport systems that remain intact in EHBRs and show marked ATP dependence, which ATP-dependent transport is involved in the biliary excretion of Z-335-Tau in vivo.     

Pharmacokinetics,Safety, and Tolerability of GLPG0259, a Mitogen-Activated Protein Kinase-Activated Protein Kinase 5 (MAPKAPK5) Inhibitor,Given as Single and Multiple Doses to Healthy Male Subjects

Background and Objectives

GLPG0259 is a small-molecule inhibitor of mitogen-activated protein kinase-activated protein kinase 5 (MAPKAPK5), a kinase enzyme that plays a role in important inflammatory pathways. The main objectives of the phase I clinical studies in early development were to characterize the pharmacokinetics, tolerability, and safety of GLPG0259 in healthy subjects, including the development of a solid dosage form (free-base pellets and fumarate salt capsules) and the potential for interaction of GLPG0259 with methotrexate.

Subjects and Methods

Four phase I studies were initiated. Study 1 was a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics of single ascending doses (1.5–150 mg) and multiple oral doses (20 and 50 mg once daily) of GLPG0259 in healthy male subjects (n = 34). Study 2 was a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics of oral multiple ascending doses of GLPG0259 (25–75 mg once daily) given for 14 days to healthy male subjects, and to get preliminary information on the potential pharmacokinetic interaction between GLPG0259 and methotrexate (n = 24). Studies 3 and 4 were open-label, randomized, crossover studies to compare the oral bioavailability of two solid dosage forms of GLPG0259 (a capsule) relative to an oral solution after a 100 mg or 50 mg single dose and to evaluate the effect of food on these formulations (n = 12 for each study).

Main Outcome Measures

The non-compartmental pharmacokinetic parameters for plasma concentrations of GLPG0259 were determined, and a population pharmacokinetic model of GLPG0259 was developed to support the planning of the number and timing of the sparse samples to be taken per patient in the phase II study. Safety and tolerability data are also summarized.

Results

The absorption of GLPG0259 was slow, with a decrease in the absorption rate with increasing dose, and there was decreased elimination, with an apparent terminal elimination half-life of 26.0 hours. On the basis of statistical analysis of variance, the exposure to GLPG0259 increased in proportion to the dose over a 30–150 mg single-dose range and a 25–75 mg repeated-dose range. Between- and within-subject variability in GLPG0259 pharmacokinetics was low/moderate (coefficient of variation [CV] 16–30%). After once-daily repeated dosing, steady-state plasma concentrations were reached at between 5 and 8 dosing days, which is consistent with the long apparent elimination half-life of GLPG0259. Food increased the bioavailability of GLPG0259 given in a solid dosage form. Co-administration of GLPG0259 with a single dose of methotrexate 7.5 mg did not result in any change in the pharmacokinetic profiles of either GLPG0259 or methotrexate.

Conclusion

In summary, the investigation of safety/tolerability and pharmacokinetics in the early development phase showed that single and repeated doses of GLPG0259 were safe and well tolerated. The most common adverse event reported was mild gastrointestinal discomfort. The pharmacokinetics characterized in healthy male subjects showed no major obstacles and supports a once-daily oral regimen in patients.