Two-way crossover bioequivalence study of alendronate sodium tablets in healthy, non-smoking male volunteers under fasted conditions.

This study was conducted in order to assess the bioequivalence of two different formulations containing 70 mg alendronate sodium (CAS 121268-17-5) under fasted conditions. One hundred twenty-two healthy male volunteers were enrolled in an open label, randomized, crossover design with a wash-out period of 20 days in one study center. Urine samples were collected up to 36 h post-dose, and the concentrations of alendronic acid were determined using a high performance liquid chromatographic method with pre-derivatization and fluorescence detection (HPLC/FL) method. The mean Ae(0-t) were 604.24 +/- 348.73 microg and 627.36 +/- 327.99 microg, while the mean R(max) were 193.87 +/- 114.68 microg/h and 202.00 +/- 107.83 microg/h for the test and reference formulations, respectively. The T(max) of the test and reference tablets were 1.26 +/- 0.58 h and 1.26 +/- 0.51 h, respectively. No significant differences of pharmacokinetic parameters between the two studied formulations were found. The 90% confidence intervals for the primary target parameters, intra-individual ratios for Ae(0-t) and R(max) of alendronic acid, were between 0.86-1.00 and 0.85-1.01, respectively, and thus within the acceptance range for bioequivalence criteria. In the light of the present study it can be concluded that the test formulation is bioequivalent to the reference formulation.

A single-dose, randomized, open-label, two-period crossover bioequivalence study comparing a fixed-dose pediatric combination of lamivudine and stavudine tablet for oral suspension with individual liquid formulations in healthy adult male volunteers.

Lamivudine (CAS 134678-17-4) is a synthetic nucleoside analogue with activity against HIV-1 and HBV. Stavudine (CAS 3056-17-5) is a synthetic thymidine nucleoside analogue, active against the human immunodeficiency virus (HIV). Lamivudine and stavudine in combination with other antiretroviral (ARV) agents are indicated for the treatment of HIV infection. As there are no suitable pediatric ARVs, adult fixed-dose ARVs are commonly used in children. This practice poses concerns about dose inaccuracy, which may lead to resistance or toxicity. A new fixed-dose combination (FDC) tablet for oral suspension, containing lamivudine 40 mg and stavudine 10 mg has been developed. An open-label, balanced, randomised, two-treatment, two-period, two-sequence, single-dose, crossover bioequivalence study was conducted following administration of a fixed-dose combination of lamivudine and stavudine tablet for oral suspension (test formulation) and innovator products (reference formulations) in healthy, adult, male human subjects under fasting condition. Multiple blood samples were collected up to 36 h post dose. Plasma concentrations of lamivudine and stavudine were assayed using validated high-performance liquid chromatography with mass spectrometry analytical method. Pharmacokinetic parameters were calculated using non-compartmental analysis and bioequivalence was assessed using a mixed effect ANOVA model. The ratio of the least-square means (FDC to individual products) and 90% confidence intervals (CIs) of AUC(0-t), AUC(0-infinity) and C(max) for lamivudine and stavudine were all within 80.00-125.00%, suggesting a similar rate and extent of ARVs exposure in the bloodstream. The FDC and individual products were equally safe and well tolerated. The current FDC of lamivudine and stavudine is expected to provide a similar efficacy/safety profile as co-administration of the individual products, a better adherence to treatment, and considerable cost savings in the treatment of HIV in children.

Bioequivalence studies of tacrolimus capsule under fasting and fed conditions in healthy male and female subjects.

The bioequivalence of tacrolimus (CAS 104987-11-3) 5 mg capsules was assessed in two single-dose, open-label, randomIzed 2-way crossover trials with a minimum washout period of 14 days; one trial was conducted under fasting condition (n = 44) and the other one under fed condition (n = 48). Blood samples were collected over a 120-h period and concentrations were assayed using a liquid chromatography tandem mass spectrometry (LCMS/MS) method. A non-compartmental method was used for calculation of pharmacokinetic parameters. Under fasting conditions, mean AUC(0-t), AUC(0-inf) and C(max) were comparable between the test (296 ng x h/mL, 318 ng x h/mL and 32 ng/ mL, respectively) and the reference formulations (289 ng x h/mL, 309 ng x h/mL and 33 ng/mL, respectively). T(max) was reached between 1.5 and 2 h post-dose. Mean AUC(0-t), AUC(0-inf) and C(max) were also comparable under fed conditions (154 ng x h/mL, 169 ng x h/mL and 7.6 ng/mL, respectively, for the test and 161 ng x h/mL, 176 ng x h/mL and 7.5 ng/mL, respectively, for the reference formulation). Under fed conditions, T(max) was reached between 5 and 6 h post-dose. 90% geometric confidence intervals were all within the acceptable 80-125% limit, suggesting bioequivalence between the generic product and the innovator product.