ABSTRACT
Aim To evaluate the pharmacokinetics and bioequivalence of two osmotic pump tablets of hydrochloride venlafaxine in Chinese healthy volunteers.Methods The fed test each enrolled twenty-six Chinese healthy volunteers in a randomized-sequence, open-label, two-period crossover single-dose oral test and reference preparations of hydrochloride venlafaxine extended-release tablets.The plasma concentrations of venlafaxine and its active metabolites O-desmethylvenlafaxine were determined by a validated liquid chromatography-tandem mass spectrometry(LC-MS/MS)method, and the pharmacokinetic parameters and bioequivalence of the two tablets were analyzed using PhoenixTM WinNonlin 6.4 software.Results The pharmacokinetic parameters of venlafaxine after single dose for the test and reference tablets were as follows: Cmax(58.50±19.47)vs(60.14±22.18)μg•L-1, AUC0-t(1 074.1±526.7)vs(1 057.9±539.7)μg•h•L-1, AUC0-∞(1 084.7±536.8)vs(1 067.8±554.0)μ g•h•L-1.The pharmacokinetic parameters of O-desmethylvenlafaxine were as follows: Cmax(101.63±29.64)vs(101.45±31.62)μg•L-1, AUC0-t(2 694.0±834.5)vs(2 702.9±946.4)μg• h•L-1, AUC0-∞(2 753.9±885.5)vs(2 753.2±988.4)μg•h•L-1.The 90% confidence intervals of the geometric mean ratios of Cmax, AUC0-t, AUC0-∞ for the test preparation and the reference preparationwere all within the equivalent interval of 80.00%-125.00%.Conclusion The test and reference preparations of hydrochloride venlafaxine extended-release tablets are bioequivalent in Chinese healthy volunteers under fed conditions.
ABSTRACT
Objective:To establish the population pharmacokinetics model of mitiglinide given by oral route in Chinese healthy volunteers using nonlinear mixed effect model (NONMEM), investigate the pharmacokinetic characteristics of mitiglinide in Chinese healthy people to evaluate the factors that can influence the clinical pharmacokinetics of mitiglinide .Methods: Clinical data from 22 healthy volunteers were collected and the experiment was with single-dose administration.The volunteers were given 10 mg mitiglinide calcium orally and mitiglinide plasma concentration was determined by LC-MS/MS.The data was analyzed by the first order conditional estimation, and the influences of fixed effect factors such as demographic index and biochemical index were quantitatively evaluated . The population pharmacokinetics model of mitiglinide was established , and the result was verified by using the VPC and self-test meth-od.Results:The result showed that mitiglinide pharmacokinetics was fit single-compartment model .The inter-individual variability could be described by an exponential model .The typical values including central volume of distribution , clearance and absorption con-stant was 2.4 L· h-1(24％), 9.82 L(4％) and 6.46 h-1(14％), respectively.The clearance was influenced by creatinine clear-ance rate , and the absorption constant was influenced by ALT .Conclusion:The population pharmacokinetic parameters were mainly influenced by creatinine clearance rate and ALT .The established population pharmacokinetics model can explain the reasons for the in -dividual variation in the plasma concentration of mitiglinide , which can be used to guide the clinical administration of Chinese people .
ABSTRACT
Aim To investigate the pharmacokinetic characteristics of silibinin in Chinese healthy volunteers.Methods Nine Chinese male healthy volunteers were divided into receiving orally a single dose of silibinin capsule corresponded 70,140 and 280 mg of silibinin,respectively,in Latin square design study.After administration of silibinin capsule,the plasma concentrations were determined by HPLC with UV detection.The pharmacokinetic parameters were analyzed by Topfit 2.0 program.Results The linearity of this method was found to be from 3.125 to 10 000 μg·L~(-1) with a lower limit of quantitation(LLOQ) of 3.125 μg·L~(-1) for silibinin.The pharmacokinetic parameters were calculated as the follows:at the three different dosages(70,140 and 280 mg),T_(1/2) was 2.44,2.38 and 2.47 h;C_(max) was 1135.6,2841.1 and 3946.9 μg·L~(-1);T_(max) was 1.35,1.26 and 1.39 h;AUC_(0-11 h) was 1287.2,3337.8 and 5398.5 μg·h·L~(-1);AUC_(0-∞)was 1300.7,3377.1 and 5453.9 μg·h·L~(-1);CL/F was 1062.1,824.7 and 943.2 ml·min~(-1);And V_d was 219.9,167.1 and 212.0 L,respectively.Conclusions The developed method is shown to be sensitive,accurate and simple,and can satisfy the requirement of pharmacokinetic study of silibinin in human.The C_(max),AUC_(0-11 h) and AUC_(0-∞) of silibinin in Chinese healthy volunteers(in ranges of 40～120 mg)are fitted with non-linear kinetic model,while there are no significant differences in T_(1/2) at the three different dosages.