Matrine sustained release tablet, capsule and injection: comparison of pharmacokinetics and relative bioavailability

Objective:To compare the pharmacokinetics and relative bioavailability between matrine sustained release tablet,matrine conventional capsule and matrine injection. Methods: Dogs were given single oral dose and multiple doses of matrine sustained release tablet, capsule or injection in a randomized crossover way. Matrine concentrations in dog plasma were determined by RP-HPLC method. Results: The results showed that the t max and c max were 300 min and (5.088±0.490) μg/ml for matrine sustained release tablet, (85±12) min and (6.360±0.215) μg/ml for the conventional capsule, and 10 min and (6.500±0.404) μg/ml for the injection. The relative bioavailability of the sustained release tablet was (153.7±9.4)% compared with that of the conventional capsule; the absolute bioavailability of the sustained release tablet was (73.5±14.2)% compared with that of the injecetion. The in vivo absorption rate of the sustained release tablet was significantly correlated with the in vitro release rate(r=0.981 2,P0.01). Conclusion: Matrine sustained release tablet, with sustained release, longer time for reaching peak, and smoothly changing concentration,can meet the requirements for drug design.