Generic fixed-dose combinations of antiretrovirals are frequently prescribed for the treatment of human immunodeficiency virus infection. A randomized, 2-way study was conducted in 24 fasting, healthy, Indian male subjects to assess bioequivalence between a single combination tablet containing lamivudine, stavudine, and nevirapine (treatment A) with respect to separate marketed tablets administered simultaneously (treatment B). Each subject received treatments A and B separated by 19 days of a drug-free washout period. Plasma concentrations of antiretrovirals, determined by a validated liquid chromatography/tandem mass spectrometry assay, were used to assess pharmacokinetic parameters such as maximum observed plasma concentration and area under the plasma concentration curve. Pharmacokinetic parameters were comparable for either treatment. As geometric mean ratios (% treatment A/treatment B) of log-transformed parameters of area under the plasma concentration curve and plasma concentration, as well as their resultant 90% confidence intervals, were within 80% to 125% and 75% to 133%, respectively, 2 treatments were considered bioequivalent in the extent and rate of absorption. Both treatments exhibited similar tolerability under fasting conditions.

The present study compared pharmacokinetic (PK) profile and single-dose tolerability of 2 marketed brands of lamivudine (3TC) 150-mg tablets, Lamivir (Cipla, Mumbai, India) and Epivir (GSK, Basingstoke, UK). The randomized, 2-treatment study was conducted in 24 fasting, healthy, Indian male subjects. Each subject received Epivir and Lamivir formulation separated by 7 days of drug-free washout period. Plasma concentrations of 3TC were used to estimate PK parameters such as maximum observed plasma concentration (Cmax) and area under plasma concentration-time curve (AUCinfinity). Geometric mean ratios (relative to Epivir) and resultant 90% CI of 3TC for Cmax and AUCinfinity were 1.00 (0.89-1.12) and 1.01 (0.94-1.07), respectively. As 90% CIs were entirely within 0.80-1.25 for log-transformed data, the 2 formulations were considered bioequivalent in the extent (AUCinfinity) and rate of absorption (Cmax and time to Cmax [tmax]). The means of primary PK parameters of 3TC, Cmax, and AUCinfinity in Indian subjects were comparable to those previously reported in the literature. Both formulations exhibited similar tolerability under fasting conditions.

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The study was designed to compare the rate and extent of absorption of two fixed dose combination tablet formulations of lopinavir (CAS 192725-17-0) and ritonavir (CAS 155213-67-5). This bioequivalence study was conducted using a standard preparation as reference and a generic alternative as test in 72 adult healthy volunteers within 18-45 years of age who received a single dose of the test or reference product under fasting conditions. A washout period of 10 d was maintained between period I and period II dosing. After dosing, blood samples were collected from 0 h (pre-dose) to 72 h postdose administration. Lopinavir and ritonavir were quantified using a validated LC-MS/MS method. The data obtained for each subject was evaluated for primary pharmacokinetic variables C(max), AUC(0-72), and AUC(0-Inf) with respect to % ratio and 90% confidence interval for log-transformed data. The 90% confidence intervals (obtained by analysis of variance, ANOVA) were well within the bioequivalence acceptance range of 80% to 125%. Thus, it can be concluded that the evaluated formulations are bioequivalent in terms of rate and extent of absorption. The safety profiles of both the test and reference formulations were comparable.

The study was designed to compare the rate and extent of absorption of a fixed dose combination tablet of lamivudine (CAS 134678-17-4) and stavudine (CAS 3056-17-5) with the concurrent administration of lamivudine tablet and stavudine capsule in 24 healthy volunteers under fasting conditions. The volunteers were randomly assigned to the test or reference treatment, with the two treatment periods separated by a washout period of at least 7 days. Plasma samples were analyzed for both analytes lamivudine and stavudine by a validated analytical method. Since the 90% confidence intervals for the "test/reference" mean ratio of the In-transformed pharmacokinetic variables C(max) AUC(0-t) and AUC(0-infinity) were clearly within the conventional bioequivalence range of 80% to 125%, the two treatments were considered bioequivalent. The safety profiles of both the test and reference formulations were comparable.