Comparative bioavailability of two estazolam tablet formulations in Indonesian healthy volunteers.
Author(s): Harahap Y, Sasongko L, Prasaja B, Indriati E, Lusthom W, Lipin
Affiliation(s): Department of Pharmacy, Faculty of Mathematic and Science, University of Indonesia, Depok, Indonesia.
Publication date & source: 2008, Arzneimittelforschung., 58(10):501-4.
Publication type: Comparative Study; Randomized Controlled Trial
AIM: To compare the bioavailability of two estazolam (CAS 29975-16-4) tablet formulations (Estalin 2 mg tablets as test formulation and 2 mg tablets of the originator product as reference formulation). METHODS: The study was conducted according to an open label, randomized two-way cross-over design with a two-week washout period. Twenty-four subjects received each of the two estazolam formulations. Blood samples for pharmacokinetic profiling were taken up to 72 h after drug administration in fasting condition. Plasma concentrations of estazolam were determined with a validated HPLC method with ultraviolet detection. Pharmacokinetic parameters were calculated from observed plasma concentration-time profiles. RESULTS: The mean AUC(0-t), AUC(0-infinity) and Cmax were 2581.38 ng x h/mL, 2934.37 ng x h/mL and 95.25 ng/mL, respectively for the test formulation and 2835.75 ng x h/ mL, 3207.73 ng x h/mL and 99.32 ng/mL, respectively, for the reference formulation. The median Tmax for both formulations was 1 h. The point estimates and 90% confidence Intervals for AUC(0-t), AUC(0-infinity) and Cmax were 91.03% (87.48-94.72%), 91.48% (86.67-96.55%) and 95.90% (92.60-99.31%) respectively, satisfying the bloequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration guidelines. CONCLUSION: These results indicate that two formulations of estazolam are bioequivalent and, thus, may be prescribed interchangeably.