Evaluation of tetrandrine sustained release calcium alginate gel beads in vitro and in vivo

Abstract

An approach for the preparation of tetrandrine sustained release calcium alginate gel beads was described. In vitro the release of tetrandrine from sustained release dosage forms went on a time of 12 hours which fitted non-Fickian diffusion with matrix erosion significantly. In vivo the plasma concentration of tetrandrine extended preparation given in dogs reached C max 2.67±0.69 mg/ml approximately at 5.67±0.58 h after oral administration. The AUC0→24 and AUC0 →∞ were 24.64±6.77 mg·h/l and 29.75±5.30 mg·h/l, respectively. The elimination half-time was 9.6±2.40 h. While a favorable correlativity existed between in vitro and in vivo with a correlative coefficient of 0.9798 through linear regression. An investigation on the quantitative relationship between in vitro release and in vivo absorption is a highly necessary work guided for manufacture, optimization and in vivo evaluation of sustained release dosage by means of in vitro release or dissolution tests. © 2009 The Pharmaceutical Society of Japan.