Bioavailability and pharmacokinetics of two sustained release formulations of mizolastine in healthy volunteers

Purpose The aim of this study was to compare the pharmacokinetic (PK) profile and relative bioavailability of two sustained release tablets containing 10 mg mizolastine in healthy, young Chinese volunteers. Methods A single oral dose of mizolastine was given under fasting conditions to volunteers aged from 21 to 24 years in this open-label, randomized, crossover study. A ten-day wash out period was applied between each of the two formulations. Plasma samples were obtained before dosing and at predetermined time points after dosing up to 48 hours and were analyzed for plasma concentration with a high-performance-liquid chromatography-UV method. PK parameters representing the extent and the rate of absorption of mizolastine were obtained. An analysis of variance, 90% confidence intervals, and two one-sided tests were employed for statistical analysis of relative difference between the two formulations. Results According to the pharmaeokinetic and statistical analysis, parameters were not statistically different between the two formulations except the peak concentration (c(subscript max))The point estimates of the ratios of AUC(subscript 0→t), AUC(subscript 0→∞) of mizolastine were (101.26 ± 9.82) 94 and (102.52 ± 8.61)% with 90% confidence intervals (CIs) of 95.5%-106.5% and 97.7%-106.994 respectively, comprised in the stipulated 80%-125% range; for c(subscript max) values, the ratios was 82.17%-15.32% with the 90% CIs of 71.79%-91.19%, fell in the recommended range of 70%-143%. Conclusions The results indicate that there is no statistically significant difference in PK parameters except c(subscript max) between the two sustained release tablets of mizolastine. The 90% CIs of AUC(subscript 0→t) AUC(subscript 0→∞) and c(subscript max) are within the predefined range. Thus, the two sustained release tablets of mizolastine are considered bioequivalent and generally well tolerated.