Pharmacokinetics and tolerability of multiple-dose rosuvastatin: An open-label, randomized-sequence, three-way crossover trial in healthy Chinese volunteers

Background: Rosuvastatin has been reported to be beneficial in the treatment of dyslipidemia. The C_max and AUC_0−t of rosuvastatin were reported to be ~2 to 4 times higher in Chinese subjects compared with white subjects after administration of a single 1-mg/kg dose.Objectives: The aims of this study were to assess the pharmacokinetics and tolerability of multiple doses of rosuvastatin in healthy Chinese volunteers.Methods: This open-label, randomized-sequence, 3-way crossover trial consisted of three 7-day treatment periods and two 10-day washout periods. Healthy volunteers were randomly allocated to 1 of 3 daily treatment regimens: rosuvastatin 5, 10, or 20 mg. To assess the pharmacokinetics and tolerability of rosuvastatin, blood samples were drawn before dosing (hour 0) on days 5, 6, and 7 and 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 12, 15, 24, 36, 48, 72, and 96 hours after the final dose was administered on day 7. A validated HPLC-MS/MS method was used to determine rosuvastatin levels. A 2-compartment pharmacokinetic model was fitted to the plasma concentration-time profiles obtained for each volunteer. Adverse events (AEs) were monitored throughout the study via subject interview, vital signs, and blood sampling. Serious AEs were those requiring hospitalization, treatment discontinuation, or resulting in death.Results: Twelve healthy Chinese volunteers (6 men: mean [SD] age, 21.8 [1.7] years; weight, 62.3 [5.8] kg; height, 174.3 [7.2] cm; 6 women: age, 20.8 [1.2] years; weight, 53.2 [4.7] kg; height, 161.3 [4.3] cm) participated in and completed the trial. The mean (SD) steady-state C_max was significantly greater after ro-suvastatin administration in the 20-mg group compared with the 5-mg group (37.69 [29.83] vs 6.17 [6.03] ng/mL; P = 0.04). The t_1/2 was significantly greater in the 20-mg group (15.51 [6.43] hours) compared with the 5-mg group (5.65 [5.08] hours; P = 0.001) and the 10-mg group (8.58 [5.17] hours; P = 0.002). The mean AUC_0−t was significantly greater in the 20-mg group compared with the 5-mg group (349.16 [257.20] vs 40.63 [39.31] ng/mL/h; P = 0.02). All AEs were considered by the investigators to be mild in intensity, with the exception of 2 cases of abdominal discomfort (1 man and 1 woman, both in the 5-mg dose group). Two women in the 20-mg group experienced dizziness and cold sweats simultaneously. In the 10-mg group, 1 woman had abdominal discomfort and nausea and 1 woman had jaw pain. All reported AEs were considered possibly related to study drug administration.Conclusions: In this small study in healthy Chinese volunteers, rosuvastatin systemic exposure appeared to be dose-proportional over the dosing range of 5 to 20 mg with multiple-dose administration. There was no accumulation of rosuvastatin in the body with the 5- and 10-mg doses. However, the results suggest that rosuva-statin might accumulate when the dose is increased to 20 mg. No serious AEs occurred in any of the 3 dosing groups.     

Single‐ and multiple‐dose tolerability and pharmacokinetics of the CRTH2 antagonist setipiprant in healthy male subjects

Chemoattractant receptor‐homologous molecule expressed on T helper (Th) 2 cells (CRTH2) is a G‐protein‐coupled receptor for prostaglandin D₂ (PGD₂), a key mediator in inflammatory disorders such as asthma and allergic rhinitis. In this study, we investigated the single‐ and multiple‐dose tolerability and pharmacokinetics (PKs) of setipiprant, an orally active, potent, and selective CRTH2 antagonist. This randomized, double‐blind, placebo‐controlled study was performed in two parts in healthy male subjects. In study Part A, single oral doses of up to 2000 mg setipiprant or placebo were given to sequential groups of eight subjects each. Additionally, the impact of food on the PKs was investigated in one‐dose group. In study Part B, two groups of subjects received 500 or 1000 mg setipiprant or placebo b.i.d. during 5.5 days. At regular intervals, tolerability variables and plasma and urine levels of setipiprant were determined. Setipiprant was well tolerated after single‐ and multiple‐dose administration. Headache was the most frequently reported adverse event. No treatment effect on tolerability variables was observed. After single‐ and multiple‐dose administration, setipiprant was rapidly absorbed and followed a biphasic elimination pattern with an elimination half‐life between 10 and 18 h. Steady‐state conditions were reached after 2–3 days and setipiprant did not accumulate. Exposure to setipiprant was lower in the presence of food. Urinary excretion of unchanged setipiprant did not exceed 7% of the administered dose. In this entry‐into‐human study, setipiprant showed good tolerability and a favorable PK profile, thus warranting its development in the treatment of inflammatory disorders.     

Evaluation of the potential for pharmacokinetic interaction between fenofibrate and ezetimibe: A phase I, open-label, multiple-dose, three-period crossover study in healthy subjects

OBJECTIVE: This study was conducted to evaluate the potential for pharmacokinetic interaction between fenofibrate and ezetimibe in healthy subjects. METHODS: This was a Phase I, open-label, multiple-dose,3-period crossover study conducted in healthy adult men and women. Subjects received fenofibrate 145 mg alone, fenofibrate 145 mg with ezetimibe 10 mg, and ezetimibe 10 mg alone for 10 consecutive days, in an order determined by computerized randomization schedule. Blood samples were collected for up to 24 hours after dosing on study day 1 and up to 120 hours after dosing on study day 10 for determination of plasma concentrations of fenofibric acid, unconjugated (free) ezetimibe, and total (conjugated and unconjugated) ezetimibe using validated high-performance liquid chromatography methods with mass-spectrometric detection. Ezetimibe glucuronide concentrations were estimated by subtracting free ezetimibe concentrations from total ezetimibe concentrations. RESULTS: Eighteen healthy adults (12 men, 6 women; 17 white, 1 black) were enrolled in the study. Their mean age was 43.4 years (range, 27-55 years), their mean weight 78.7 kg (range, 60-98 kg), and their mean height 174.9 cm (range, 156-194 cm). Coadministration of multiple doses of fenofibrate and ezetimibe produced no statistically significant effect on the pharmacokinetics of fenofibric acid but significantly increased exposures to total ezetimibe and ezetimibe glucuronide (P < 0.05). Using point estimates, co-administration of fenofibrate and ezetimibe increased AUC central values for total ezetimibe and ezetimibe glucuronide by 43% (90% CI, 29-59) and 49% (90% CI, 34-65), respectively. CONCLUSION: In these healthy volunteers, coadministration of multiple doses of fenofibrate and ezetimibe had no statistically significant effect on the pharmacokinetics of fenofibric acid but was associated with a significant increase in exposure to total ezetimibe and its metabolite ezetimibe glucuronide.     

Nonlinear pharmacokinetic properties of mildronate capsules: a randomized,open‐label,single‐ and multiple‐dose study in healthy volunteers

Mildronate has been used as antianginal drug in parts of Europe for many years, but its pharmacokinetic (PK) properties in humans remain unclear. This study was designed to assess and compare the PK properties of mildronate capsules after single escalating oral dose and multiple doses in healthy Chinese volunteers. Volunteers were randomly assigned to receive a single dose of 250, 500, 1000, 1250 or 1500 mg of mildronate capsules. Those who received the 500‐mg dose continued on the multiple‐dose phase and received 500 mg three times a day for 13 days. Plasma drug concentrations were analysed by ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC‐MS/MS). Tolerability was assessed throughout the study. A total of 40 Chinese volunteers were enrolled in the study. No period or sequence effect was observed. Area under the concentration and C_max were increased proportionally with the dose levels, whereas t_1/2 and V_d/f were dependent on the dose. Nonlinear PK properties were found at doses of 250–1500 mg. There was an accumulation after multiple‐dose administration. No serious adverse events (AEs) were reported in the PK study. The formulation was well tolerated.     

Safety, tolerability, and pharmacokinetics of TAS-108 in normal healthy post-menopausal female subjects: a phase I study on single oral dose

OBJECTIVES: The present study was conducted to evaluate the safety, tolerability, and pharmacokinetics of TAS-108 after ascending single oral doses and to analyse preliminarily the effect of food on the pharmacokinetics of TAS-108 in normal healthy post-menopausal female subjects. METHODS: Twelve healthy subjects participated in an open-label, ascending single-dose, alternating group, safety, tolerance, and pharmacokinetic study of TAS-108 administered orally to two groups of the subjects, one given alternating doses of 10, 40, 120 mg (group A) and the other of 20, 80, 160 mg (group B), in the fasting state. In addition, six subjects (group A) were administered an additional dose at 120 mg TAS-108 after food consumption. Plasma and urine samples for measurement of TAS-108 were analysed by validated analytical procedures using a liquid chromatographic method with tandem mass spectrometric detection (LC/MS/MS). RESULTS: There was no dose-dependent increase in any adverse events (AEs), and there were no serious AEs or deaths. TAS-108 was readily absorbed following oral administration of the 80-, 120- and 160-mg doses. Plasma TAS-108 levels steadily declined, generally in a mono-exponential manner, with overall mean t(1/2) values ranging from 3.04 to 4.43 h in the fasting groups. Administration of TAS-108 after a high-fat meal markedly increased the bioavailability of the drug. The mean C(max) and AUC(0--t) values increased after a high-fat breakfast by 182 and 191% compared with the fasting value respectively. CONCLUSIONS: In this escalating dose study of TAS-108, the drug was well tolerated by the participants. The maximum and systemic exposure to TAS-108 tended to increase with increasing dose and its bioavailability markedly increased after high-fat food intake.     

Pharmacokinetic and pharmacodynamic characteristics of aranidipine sustained-release, enteric-coated tablets in healthy Chinese men: a phase I, randomized, open-label, single- and multiple-dose study

OBJECTIVE: The aim of this study was to explore the pharmacokinetic (PK) and pharmacodynamic (PD) properties and safety profiles of aranidipine and its active M-1 metabolite in healthy Chinese men. METHODS: This Phase I, randomized, open-label, single- and multiple-dose study included healthy, nons-moking male volunteers aged 18 to 45 years. In the single-dose study, subjects were randomly assigned to receive oral sustained-release, enteric-coated aranidipine tablets 5, 10, or 20 mg. In the multiple-dose study, volunteers who had been assigned to the aranidipine 10-mg group in the single-dose study received this dose for 7 days. In the single-dose study, blood samples for the PK analyses were obtained immediately before dosing and at regular intervals up to 36 hours after dosing. In the multiple-dose study, predose blood samples were collected on days 4 through 7; on the last day of treatment, blood samples were drawn at the same times as in the single-dose study. Plasma concentrations of aranidipine and M-1 were determined using a high-performance liquid chromatography method with tandem mass-spectrometric detection. For the PD analyses, blood pressure (BP) and heart rate were measured before dosing, at regular intervals up to 24 hours after dosing, and after the final dose during repeated administration. Tolerability was assessed throughout the study, based on adverse events, physical examinations, electrocardiography, vital signs, and laboratory tests. RESULTS: The study enrolled 30 healthy Chinese men (mean [SD] age, 23 [2] years; mean body weight, 66 [7] kg; mean height, 174 [6] cm). In the single-dose study, the mean t(1/2) for aranidipine 5, 10, and 20 mg was 3.0 (2.7), 2.7 (1.1), and 3.1 (2.2) hours, respectively; mean T(max) was 4.9 (0.4), 4.4 (1.0), and 4.3 (0.9) hours; mean C(max) was 1.1 (0.6), 2.4 (0.8), and 4.0 (2.0) microg/L; and mean AUC(last) was 4.1 (1.4), 10.3 (2.3), and 20.9 (4.2) microg . h/L. There were no significant differences in any PK parameter between dose groups. For M-1, the corresponding values were 4.6 (1.0), 4.1 (0.5), and 4.1 (0.3) hours for t(1/2); 5.6 (2.0), 5.0 (1.6), and 5.0 (0.8) hours for T(max); 18.4 (0.6), 40.5 (10.0), and 39.2 (11.3) microg/L for C(max); and 143.5 (39.1), 304.5 (108.2), and 403.9 (73.5) microg . h/L for AUC(last). Only dose-normalized Cmax and AUC(last) differed significantly between dose groups (P < 0.001 and P = 0.018, respectively). After multiple doses, the mean values for t(1/2), T(max), C(max), and AUC(0-infinity) for aranidipine 10 mg were 2.3 (0.9) hours, 5.0 (1.2) hours, 3.1 (1.1) microg/L, and 13.8 (3.6) microg . h/L, respectively. Repeated oral administration of aranidipine 10 mg was associated with a significant increase in AUC(last) (P = 0.027). The corresponding values for M-1 were 4.8 (0.9) hours, 5.7 (1.3) hours, 40.0 (11.3) microg/L, and 381.8 (161.2) microg . h/L. There were no significant differences between dose groups in any PK parameter for M-1 after single or multiple doses. In the PD analyses, the mean change from baseline in diastolic BP was statistically significant in all groups (P < 0.01) except the aranidipine 10-mg group in the single-dose study. Three volunteers (10%) reported adverse events after administration of a single dose: headache (10-mg group), palpitations (20-mg group), and dizziness (20-mg group). The headache and palpitations were considered possibly related to study drug. CONCLUSIONS: The results of this small study in healthy Chinese men suggest that the PK properties of aranidipine were linear with respect to dose, whereas the PK properties of the active M-1 metabolite were not fully linear. There was no apparent accumulation of aranidipine or M-1 with administration of single and multiple doses. Aranidipine was generally well tolerated.     

Pharmacokinetics of depside salts from Salvia miltiorrhiza in healthy Chinese volunteers: A randomized, open-label, single-dose study

Background: Depside salts from Salvia miltiorrhiza, with active components of lithospermic acid B (LSB), rosmarinic acid (RA), and lithospermic acid (LA), are a multicomponent drug marketed in China for the treatment of coronary heart disease.Objectives: The aims of this study were to determine the concentrations of LSB, RA, and LA in human plasma and urine, and to compare the pharmacokinetic properties of depside salts from S miltiorrhiza in healthy Chinese volunteers.Methods: A randomized, open-label, single-dose study was conducted in healthy Chinese volunteers. Participants were randomly assigned to receive a single intravenous infusion of 100 or 200 mg of depside salts from S miltiorrhiza. Blood was collected through a venous cannula prior to study drug administration (0 min) and at 10, 20, 30, 60, 65, 70, 80, and 90 minutes and 2, 3, 4, 6, 8, 12, and 24 hours after study drug administration. Urine samples were taken before study drug administration (0) and at 0 to 12 and 12 to 24 hours after study drug administration. LSB, RA, and LA concentrations in serum and urine were analyzed by an LC-MS/MS method. Tolerability was determined by clinical assessment; vital signs (ie, blood pressure, heart rate, breathing rate, body temperature) monitoring at baseline and at the end of the study, clinical laboratory tests (ie, hematology, blood biochemistry, hepatic function, renal function, urinalysis), 12-lead ECG measurements, and physical examinations at baseline and after completion of the study.Results: Twelve Chinese volunteers (6 males, 6 females; mean [SD] age, 25.2 [3.8] years; mean height, 165.7 [8.9] cm; mean body mass index, 21.6 [2.5] kg/m²) were enrolled in the study. Peak plasma concentrations of LSB, RA and LA were observed at 0.3 to 1 hour following the 1-hour intravenous infusion, with respective mean (SD) Cmax of 4925 (1861), 174 (61), and 361 (101) ng/mL for the 100-mg dose and 10,285 (2259), 308 (77), and 674 (85) ng/mL for the 200-mg dose. The AUC_last values for LSB, RA, and LA were 4537 (1265), 129 (28), and 1229 (330) ng/mL/h, respectively, for the 100-mg dose and 10,426 (2589), 260 (53), and 2792 (729) ng/mL/h for the 200-mg dose. No significant difference in pharmacokinetic parameters was observed between male and female subjects. Three metabolites were found in the plasma with low concentrations. The urinary excretion recoveries of LSB, RA, and LA were 0.58% (0.42%), 25.21% (20.61%), and 10.02% (7.72%) for the 100-mg dose and 0.38% (0.18%), 20.11% (10.50%), and 6.34% (3.20%) for the 200-mg dose. No adverse events were reported by the subjects or found by the investigators in the analysis of vital signs, 12-lead ECG measurements, physical examinations, or clinical laboratory tests.Conclusions: Following single intravenous infusion of 100 or 200 mg of depside salts from S miltiorrhiza to healthy Chinese subjects, no statistical differences in pharmacokinetic parameters were observed between males and females. The 2 doses of depside salts from S miltiorrhiza were clinically well tolerated during the study.     

Pharmacokinetic properties of lansoprazole (30-mg enteric-coated capsules) and its metabolites: A single-dose, open-label study in healthy Chinese male subjects

Background: Lansoprazole, a benzimidazole derivative, is indicated for the treatment of various peptic diseases. It is metabolized mainly in the liver, and its primary active metabolites present in plasma are 5′-hydroxy lansoprazole and lansoprazole sulfone. Few data are available on the pharmacokinetic properties of lansoprazole, 5′-hydroxy lansoprazole, and lansoprazole sulfone, which can be used to measure cytochrome P450 (CYP) 2C19 activity.Objectives: The aims of this study were to investigate the clinical plasma pharmacokinetic properties of lansoprazole and its metabolites in healthy Chinese male volunteers, and to assess the influences of CYP2C19 on the pharmacokinetics of lansoprazole.Methods: Healthy adult Chinese male volunteers were enrolled in this single-dose, open-label study. All patients received a single oral enteric capsule containing 30 mg of lansoprazole after a 12-hour overnight fast. Serial blood samples were collected immediately before (0 hour) and at 20, 40, 60, 90, 120, and 150 minutes and 3, 4, 6, 8, 10, 12, 15, and 24 hours after study drug administration. The plasma concentrations of lansoprazole, 5′-hydroxy lansoprazole, and lansoprazole sulfone were determined using a validated internal standard high-performance liquid chromatography—tandem mass spectrometry (HPLC-MS/MS) method. Pharmacokinetic properties (including C_max, T_max, elimination t_½ [t_½z], mean residence time [MRT], AUC_0-24, AUC_0−∞, apparent oral clearance [CL_z/F], and apparent volume of distribution [V_z/F]) were determined using the noncompartmental method.Results: Twenty volunteers (mean [SD] age, 34.9 [2.9] years; weight, 64.6 [2.2] kg; height, 171.3 [3.3] cm) were enrolled in and completed the study. The mean (SD) pharmacokinetic properties of lansoprazole were as follows: C_max, 1047 (344) ng/mL; T_max, 2.0 (0.7) hours; t_½z, 2.24 (1.43) hours; MRT, 3.62 (0.87) hours; AUC₀₋₂₄, 3388 (1484) ng/mL/h; AUC_0-∞, 3496 (1693) ng/mL/h; CL_z/F, 9.96 (3.74) L/h; and V_z/F, 32.83 (11.74) L. The findings with 5′-hydroxy lansoprazole and lansoprazole sulfone, respectively, were as follows: C_max, 111.2 (41.8) and 66.6 (52.9) ng/mL; T_max, 2.1 (0.8) and 1.9 (0.8) hours; t_½z, 2.31 (1.18) and 2.52 (1.54) hours; and AUC₀₋₂₄, 317.0 (81.2) and 231.9 (241.7) ng/mL/h. No adverse events were reported throughout the study.Conclusions: In these healthy Chinese male volunteers administered a single oral dose of lansoprazole 30 mg, absorption of lansoprazole was rapid (mean C_max, 1047 ng/mL; T_max, ~2.0 hours). Its 2 primary active metabolites, 5′-hydroxy lansoprazole and lansoprazole sulfone, were identified in measurable quantities in plasma (C_max, 111.2 and 66.6 ng/mL, respectively; and T_max, 2.1 and 1.9 hours). The plasma t_½z did not appear to reflect the duration of suppression of gastric acid secretion: the t_½z values of lansoprazole and the 2 metabolites were ~2 to 2.5 hours, while the acid-inhibitory effect lasted >24 hours. C_max, AUC, and t_½z of lansoprazole, and especially lansoprazole sulfone, varied. Differences in metabolism types and/or genotype of CYP2C19 should be taken into account when planning a lansoprazole dosing regimen.     

Pharmacokinetics of duloxetine hydrochloride enteric-coated tablets in healthy Chinese volunteers: A randomized,open-label,single- and multiple-dose study

Background: Duloxetine hydrochloride is a balanced selective serotonin and norepinephrine reuptake inhibitor. Despite being widely used for the treatment of major depressive disorder in China, little information is available on the pharmacokinetic (PK) properties of duloxetine in Chinese subjects.Objectives: This study was designed to determine the concentration of duloxetine in human plasma and to compare the PK properties of duloxetine after administration of single and multiple doses of duloxetine in healthy Chinese volunteers.Methods: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining the concentration of duloxetine in human plasma was developed and applied to this single-center, open-label, single- and multiple-dose PK study. Subjects were randomized to receive a single dose of 30, 60, or 90 mg of duloxetine. Those who received the 30-mg dose continued on to the multiple-dose phase and received 30 mg twice daily for 7 days. In the single-dose phase, sequential blood samples were collected from 0 to 60 hours after drug administration. In the multiple-dose phase, samples were obtained before drug administration on days 4, 5, 6, and 7 to determine the Cssmin of duloxetine; on day 7, samples were collected from 0 to 60 hours after drug administration. The PK parameters that were calculated included C_max, T_max, t_1/2, AUC_0?t AUC_0?∞, CL, V_d, C_ssmax, C_ssmin, C_ssav, AUC_ss, AUC_ss(0?t), and C_max:C_min ratio. All values were expressed as mean (SD). Tolerability was assessed throughout the study.Results: The LC-MS/MS method was developed and validated. The standard calibration curve was linear in the concentration range from 0.89 to 106.8 ng/mL; the correlation coefficient was >0.995. The methodo-logic recovery and extraction recovery ranged from 87.22% to 113.75% and 72.81% to 89.96%, respectively. Both the intraday and interday relative SDs were <11%. Thirty Chinese subjects (3 groups of 10 subjects [5 men, 5 women] each) were enrolled in the single-dose phase of the PK study. The mean (SD) age of the subjects was 23.2 (1.8) years (range, 21–25 years); their mean (SD) weight was 61.0 (7.7) kg (range, 52–80 kg) and height was 169.0 (7.1) cm (range, 155–180 cm). The main PK parameters for duloxetine after administration of a single oral dose of 30, 60, and 90 mg were as follows: C_max = 22.46 (15.15), 44.40 (17.18), and 60.78 (27.84) ng/mL, respectively; AUC_0–60 = 328.64 (203.64), 696.04 (337.82), and 1219.33 (598.29) ng/mL · h^?1; AUC_0?∞) = 359.68 (201.01), 733.82 (343.40), and 1280.51 (644.81) ng/mL · h^?1; T_max = 6.83 (1.99), 6.10 (1.29), and 6.60 (1.58) hours; t1/2 = 12.95 (3.64), 12.81 (2.31), and 11.66 (2.06) hours; CL = 107.90 (53.05), 98.41 (41.98), and 109.58 (52.74) L/hour; and V_d = 2518.88 (1707.71), 1879.74 (999.09), and 1858.47 (1203.69) L. The 10 subjects who received the 30-mg dose in the single-dose phase continued on to the multiple-dose phase and received 30 mg of duloxetine twice daily for 7 days. Mean (SD) values for the main PK parameters for duloxetine after administration of multiple doses were as follows: C_ssmax = 47.33 (16.95) ng/mL; C_ssmm = 27.92 (9.46) ng/mL; AUC_ss(0?t) = 407.25 (125.94) ng/mL · h^?1; C_ssav = 33.94 (13.00) ng/mL; T_max = 6.36 (0.92) hours; t_1/2 = 11.19 (1.98) hours; CL = 83.12 (28.75) L/hour; and V_d = 1359.01 (590.06) L.Conclusions: In these healthy Chinese subjects, AUC and Cmax increased proportionally with the dose, whereas t_1/2 was independent of the dose. Linear PK properties were found at doses of 30 to 90 mg. No statistically significant differences were observed between the PK parameters for the subjects in the multiple-dose phase (t_1/2, CL, V_d) and those for subjects in the single-dose phase. The AUC and C_max were greater after administration of multiple doses than after administration of a single dose, suggesting du-loxetine accumulation with multiple-dose administration of 30 mg.     

Pharmacokinetics of rosuvastatin in healthy Chinese volunteers living in China: A randomized,open-label,ascending single- and multiple-dose study

Background: Cross-study comparisons suggest that systemic exposure (AUC) to rosuvastatin calcium, a 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitor, may be ~2-fold higher in Asian subjects living in Asian countries than in white subjects living in Western countries.Objective: This study was conducted to determine the pharmacokinetic characteristics of rosuvastatin and its metabolites after single and multiple doses of rosuvastatin in healthy Chinese subjects living in China.Methods: This was an open-label, ascending singleand multiple-dose study. Subjects were randomly assigned to receive rosuvastatin 5, 10, or 20 mg. Each subject received 1 tablet of the assigned treatment on day 1 and days 4 through 10. Plasma concentrations of rosuvastatin, N-desmethyl rosuvastatin, and rosuvastatin lactone were measured through 72 hours after administration of single doses and through 96 hours after administration of multiple doses. Blood samples were obtained within 30 minutes before dosing on days 7, 8, and 9 for the assessment of pharmacokinetic parameters at steady state. Noncompartmental pharmacokinetic analysis was performed to determine the C_max and AUC_0?t for rosuvastatin, N-desmethyl rosuvastatin, and rosuvastatin lactone after single and multiple doses of rosuvastatin. Tolerability assessments were conducted throughout the study.Results: Of the 36 enrolled subjects, only 1 was female. The mean age of subjects in the rosuvastatin 5-, 10-, and 20-mg groups was 22.4, 21.3, and 22.4 years, respectively. Weight and height ranged from 54 to 85 kg and from 161 to 189 cm, respectively. Geometric mean C_max values for rosuvastatin after administration of single doses of rosuvastatin 5, 10, and 20 mg were 8.33, 10.76, and 19.17 ng/mL, respectively; the corresponding geometric mean AUC_0?t values were 57.63, 88.89, and 163.87 ng · h/mL. At steady state, values for C_max were 8.31, 8.41, and 20.73 ng/mL; the corresponding geometric mean AUC values were 64.87, 77.29, and 178.64 ng · h/mL. After administration of multiple doses of rosuvastatin 5, 10, and 20 mg, the accumulation ratios were 1.23, 0.95, and 1.23, respectively, indicating minimal accumulation of rosuvastatin. Circulating concentrations of N-desmethyl rosuvastatin and rosuvastatin lactone were well below those of rosuvastatin after administration of single and multiple doses of rosuvastatin.Conclusions: Increases in C_max, AUC_0?t, C_max,ss, and AUC_ss were observed with increasing single and multiple doses of rosuvastatin 5, 10, and 20 mg. The increase in exposure with increasing doses was lower than would be expected under conditions of strict proportionality. Rosuvastatin exhibited little accumulation on repeated administration. All rosuvastatin doses were well tolerated in these Chinese subjects.     

Bioequivalence study of two formulations of enalapril, at a single oral dose of 20 mg (tablets): A randomized, two-way, open-label, crossover study in healthy volunteers

Background: Enalapril maleate is the monoethyl ester prodrug of enalapril- at, an angiotensin-converting enzyme inhibitor indicated in the management of essential and renovascular hypertension, and in the treatment of congestive heart failure and in asymptomatic patients with left ventricular dysfunction and an ejection fraction of ≥35%. Enalapril has little pharmacologic activity until hydrolyzed in vivo to enalaprilat.Objective: The aim of the present study was to compare the bioavailability and tolerability of 2 commercial brands (test and reference formulations) of enalapril tablets (20 mg), described as the rate and extent of absorption of the active moiety, to assess their bioequivalence.Methods: This single-dose, randomized, 2-way, open-label, crossover study in healthy volunteers aged 18 to 40 years was conducted at the Clinical Pharmacology Study Unit, Hospital Clínico San Carlos (Madrid, Spain). Subjects were randomized to receive (under fasting conditions) either the test or reference formulation of enalapril (20-mg tablet) at study period 1 and the opposite formulation at study period 2. Study periods were separated by a washout period of at least 7 days. During each study period, 15 plasma extractions were made to determine enalapril and enalaprilat plasma concentrations and to calculate the pharmacokinetic (PK) properties (maximal plasma drug concentration [C_max], time to C_max [T_max], area under the plasma concentration-time curve [AUC] to the last measurable concentration [AUC_t], AUC from time 0 to infinity [AUC_0−∞], mean residence time, and elimination half-life []) of both. Physical examination, subject interview, laboratory analyses, electrocardiogram, and blood pressure (BP) were used to assess tolerability.Results: Twenty-four subjects were included in the study (12 men, 12 women; mean [SD] age, 22.8 [2.2] years [range, 19-30 years]). Of these, 1 subject (4.2%) withdrew from the study for personal reasons; thus, PK and statistical analyses included results from 23 subjects. No statistically significant sequence or period effect was found. T_max was not statistically different between the 2 formulations, and the 90% CI calculated for T_max for the difference of the medians was within the predefined range. The 90% CIs of the logarithmically transformed concentration-derived parameters (C_max AUC_t, and AUC_0−∞) also were within the predefined range; thus, the 2 formulations are considered bioequivalent. For both formulations, systolic and diastolic BPs showed significant reductions compared with baseline values (P < 0.05). Seven adverse effects were recorded, all of them transient and none of severe intensity.Conclusions: In this study of 2 commercial brands (test and reference formulations) of enalapril in healthy subjects, designed and conducted under Good Clinical Practice guidelines, a similar rate and extent of absorption for both formulations were found to be bioequivalent. Both formulations produced a significant decrease in BP values and were generally well tolerated.     

Effect of eslicarbazepine acetate on the pharmacokinetics of digoxin in healthy subjects

Eslicarbazepine acetate (ESL) is a new-generation voltage-gated sodium channel blocker, which has been demonstrated to be effective and well tolerated in the treatment of epilepsy. The primary objective of this study was to investigate the effect of ESL on the pharmacokinetics of digoxin. This study was a randomized, double-blind, placebo-controlled, two-way crossover study of 12 healthy subjects (six men and six women). The study included two 8-day treatment periods with a washout of ≥10 days. In each period, subjects received either ESL 1200 mg once-daily or placebo, concomitantly with a loading oral dose of digoxin 0.5 mg on days 1 and 2, followed by a once-daily maintenance dose of 0.25 mg on days 3–8. Maximum serum digoxin plasma concentrations ( C _max) were reached ( t _max) at 0.5–2.0 h post-dose (median = 1.0 h) and at 0.5–4.0 h post-dose (median = 1.0 h) with Reference (digoxin plus placebo) and Test (digoxin plus ESL) treatments, respectively. The Test/Reference digoxin geometric mean ratios and 90% confidence intervals (90% CI) were 0.96 and 0.90–1.03 for the area under the plasma concentration–time curve over the dosing interval (AUC_0–24) and 0.85 and 0.68–1.07 for C _max. The 90% CI was within the bioequivalence range (0.80–1.25) for AUC_0–24, thus demonstrating bioequivalence. The 90% CI was outside the 0.80–1.25 range for digoxin C _max, but it appeared to be caused by a higher variability in digoxin C _max following co-administration of digoxin with placebo than with ESL. Co-administration of ESL and digoxin was well tolerated. Concomitant administration of ESL has no clinically relevant effect in the systemic exposure to digoxin.     

Safety, tolerability, and pharmacokinetics of intravenous oseltamivir: single- and multiple-dose phase I studies with healthy volunteers

There is an unmet need for an intravenous (i.v.) neuraminidase inhibitor, particularly for patients with severe influenza who cannot take oral medication. Two phase I pharmacokinetic and safety studies of i.v. oseltamivir were carried out in healthy volunteers. The first was an open-label, randomized, four-period, two-sequence, single-dose trial of 100 mg, 200 mg, and 400 mg oseltamivir i.v. over 2 h and a 75-mg oral dose of oseltamivir. The second was a double-blind, placebo-controlled, parallel-group, multiple-dose study in which participants were randomized to 100 mg or 200 mg oseltamivir or placebo (normal saline) i.v. over 2 h every 12 h for 5 days. Exposure to the active metabolite oseltamivir carboxylate (OC) after dosing achieved with 100 mg oseltamivir administered i.v. over 2 h was comparable to that achieved with 75 mg administered orally. Single i.v. doses of oseltamivir up to 400 mg were well tolerated with no new safety signals. Multiple-dose data confirmed good tolerability of 100 mg and 200 mg oseltamivir and showed efficacious OC exposures with 100 mg i.v. over 2 h twice daily for 5 days. These results support further exploration of i.v. oseltamivir as an influenza treatment option for patients unable to take oral medication.     

Relative bioavailability and pharmacokinetics of a new sibutramine formulation in healthy male subjects: a randomized, open-label, two-period, comparative crossover study

BACKGROUND: Sibutramine is an orally administered, centrally acting antiobesity drug. Sibutramine hydrochloride monohydrate is the conventional formulation, whereas sibutramine mesylate hemihydrate is a newly developed formulation. Drugs formed from different salts may differ in their solubility profiles and dissolution rates, which may affect their rate of absorption and thus their onset, duration, and intensity of effect. OBJECTIVE: This study was conducted to compare the relative bioavailability and pharmacokinetics of the new sibutramine formulation (test) with those of the conventional formulation (reference). METHODS:: This was a single-center, randomized, open-label, 2-period, comparative crossover study in healthy male subjects. All subjects received a single 15-mg oral dose of sibutramine hydrochloride monohydrate (reference) and a single 17.3-mg oral dose of sibutramine mesylate hemihydrate (test), both containing 12.55 mg sibutramine base. The 2 doses were separated by a 2-week washout period. Blood samples for pharmacokinetic analysis were collected during a 72-hour period after treatment. Safety parameters were assessed, including adverse events, hematology and biochemistry, urinalysis, and electrocardiography. Plasma concentrations of the active metabolites of sibutramine (desmethylsibutramine [M1] and didesmethylsibutramine [M2]) were determined, and the pharmacokinetic characteristics of the 2 formulations were compared using noncompartmental analysis. RESULTS: Sixteen subjects (mean [SD] age, 24.3 [2.3] years [range, 20-25 years]; mean [SD] body weight, 66.1 [5.1] kg [range, 57-77 kg]) were enrolled in and completed the study. The plasma concentration-time profiles of M1 and M2 were similar after administration of both formulations. The reference and test formulations showed pharmacokinetic equivalence with respect to M1 and M2. The relative bioavailability of the test drug was 117.6% for M1 and 102.4% for M2. The 90% Cls for the ratios of the log-transformed C(max) and AUC values were within the predetermined equivalence range of 80% to 125%. There were no significant changes in physical, biochemical, hematologic, or urinalysis variables during the study. Neither formulation was associated with any serious adverse events. CONCLUSION: In this study in healthy male subjects, the 2 sibutramine formulations were pharmacokinetically equivalent, and the newly developed formulation had a safety profile comparable to that of the conventional formulation.     

Pharmacokinetic and Safety Profile of Ivabradine in Healthy Chinese Men: A Phase I,Randomized, Open-Label,Increasing Single- and Multiple-Dose Study

Background

Ivabradine is a pure heart rate–lowering agent that acts by inhibiting I(f), an important ionic current involved in pacemaker activity in the cells of the sinoatrial node. In the 2012 European Society of Cardiology Guidelines on Heart Failure, it was recommended that patients with a persistently high heart rate, despite treatment with an evidence-based dose of a β-blocker, should be considered for treatment with ivabradine.

Objective

The aim of this study was to explore the pharmacokinetic/pharmacodynamic properties and safety profile of ivabradine in healthy Chinese men.

Methods

This Phase I, randomized, open-label, parallel-arm, single- and multiple-dose study was conducted at the Clinical Pharmacology Center of the Cardiovascular Institute and Fu Wai Hospital at the Chinese Academy of Medical Sciences & Peking Union Medical College in Beijing, People’s Republic of China. Healthy, nonsmoking volunteers were randomly assigned to 1 of 3 treatment groups based on treatment with 5, 10 or 20 mg of ivabradine. After a single dose, the subjects assigned to the 3 dose groups received repeated oral doses of ivabradine BID for 6 days. The plasma concentrations of ivabradine were determined by using a HPLC-MS/MS method. Systolic and diastolic blood pressure and heart rate measurements were taken, and ECG and Holter monitoring was performed. Tolerability was assessed throughout the study by physical and ophthalmologic examinations, vital signs measurement, laboratory analyses, and monitoring of adverse effects.

Results

A total of 36 healthy Chinese men were enrolled in the study. After the single dose, plasma ivabradine C_max and AUC increased approximately linearly with dosage, no statistically significant differences were found in t_½ or T_max between the dose groups. After multiple doses, there was no significant change in T_max compared with the results after a single dose. After repeated doses, t_½, C_max, and AUC increased significantly (P < 0.001). After a single dose, a significant reduction in heart rate at 2 hours’ postdose was observed in the highest dose group, whereas after repeated doses, a significant reduction in heart rate was observed from 2 to 4 hours’ postdose for all 3 groups. The mean (SD) heart rate after repeated doses decreased 12.5 (4.8), 12.4 (6.9), and 20.5 (5.8) beats/min for the 5-, 10-, and 20-mg dose groups, respectively. No clear trend in the changes in QTc, systolic and diastolic blood pressures, or respiration rate was observed. Ivabradine was well tolerated in these healthy Chinese men.

Conclusions

The results of the study in a small population of healthy Chinese men suggest that the PK properties of ivabradine are linear with respect to dosing. After single and repeated oral administration of ivabradine, a significant decrease in heart rate was observed. Ivabradine appeared well tolerated in the population studied. Trial identifier: ACTRN1261300027741.