Bioequivalence of fixed dose combination of atorvastatin 10 mg and aspirin 150 mg capsules: a randomized, open-label, single-dose, two-way crossover study in healthy human subjects.

The present study evaluated the bioavailability and bioequivalence of fixed dose combination test formulation (atorvastatin 10 mg and aspirin 150 mg capsule) against marketed reference formulations (Lipitor® tablets 10 mg and Nu-Seals tablets 75 mg). This study was an open label, balanced, randomized, 2-treatment, 2-period, 2-sequence, single dose, crossover trial in 80 healthy adult human volunteers under fasting conditions. Plasma concentrations of atorvastatin, aspirin and salicylic acid were quantified using LC-MS/MS method. Pharmacokinetic parameters were estimated by noncompartmental model and mean pharmacokinetic parameters were comparable between test and reference formulations. The mean pharmacokinetic parameters (AUC0-t, AUC0-∞, Cmax, Cmax /AUC0-t and Cmax/AUC0-∞) for atorvastatin test and reference formulations were (52.69 ng.h/mL, 55.64 ng.h/mL, 9.45 ng/mL, 0.18 1/h and 0.17 1/h) and (52.20 ng.h/mL, 55.38 ng.h/mL, 10.25 ng/mL, 0.20 1/h and 0.19 1/h) respectively; and for aspirin were (1 378.62 ng.h/mL, 1 383.90 ng.h/mL, 1 022.18 ng/mL, 0.75 1/h and 0.75 1/h) and (1 314.17 ng.h/mL, 1 314.50 ng.h/mL, 985.90 ng/mL, 0.75 1/h and 0.75 1/h) respectively. Where as for salicylic acid, above parameters were (42 357.57 ng.h/mL, 44 139.47 ng.h/mL, 9 820.15 ng/mL, 0.24 1/h and 0.23 1/h) and (40 217.08 ng.h/mL, 42 032.44 ng.h/mL, 9 569.18 ng/mL, 0.24 1/h and 0.24 1/h) respectively for test and reference formulations. The 90% confidence intervals of atorvastatin and salicylic acid for AUC0-t, AUC0-∞, Cmax, Cmax /AUC0-t and Cmax/AUC0-∞ parameters were found to be within the acceptable regulatory bioequivalence limits. In conclusion, the new fixed dose combination test formulation was bioequivalent to the reference formulations under fasting conditions.