Preparation of captopril delayed-onset,sustained release tablets
Luo Kuai-yan · The Chinese Journal of Modern Applied Pharmacy · 2005
OBJECTIVE To prepare captopril delayed-onset,sustained release tablets that start releasing after a lag time 5h. METHODS Captopril delayed-onset,sustained release tablets were prepared with dry-coated technology.Central composite design was used to optimize the formulation, artificial neural networks was used to predict the lag time of release,and multiple regression was performed using statistic analysis software (SAS).The observed values of the lag time of captopril delayed-onset,sustained release tablets prepared under the optimum condition were compared with the predicted.The out shell composition was confirmed. The composition of core tablets was optimized using captopril sustained release tablets as reference preparation and the similarity factor(f_ 2 ) as the evaluation standard. Then the formulation of captopril dry-coated tablets was finally confirmed.RESULTS The lag time in vitro of captopril delayed-onset,sustained release tablets prepared under the optimum condition was 5h. The tablets had similar release behavior to reference products(f_ 2 =64.06) and the drug release pattern was accorded with the first order kinetics.CONCLUTION The lag time of this dry-coated tablets is only controlled by the composition of out shell. The sustained release after release starting is controlled by both out shell and core tablet.