RESUMO
OBJECTIVE:To investigate the characteristics of drug release and the factors affecting the in vitro dissolubility of diclofenac potassium double-layer tablets(DPD).METHODS:UV-spectrophotometry and rotating basket method in the pha-rmacopeia of China 2000 edition were used to determine the in vitro dissolubility of DPD and Higuchi equation was adopeted to simulate the in vitro drug release.The main parameters of dissolution were stastistically analysed.RESULTS:Dissolution parameters of DPD were as follows:T0.3=0.10h,Td=3.30h,T0.9=9.19h.Hardness of tablets did not affect the dissolution rate significantly;pH of dissolution media significantly influenced on the rate.Rotation speed had a significant effect on dissolution action only at the beginning of test.CONCLUSION:DPD has good properties of fast and sustained release.Proper media is the key of in vitro drug release test,however,the ultimate results should be based on in vivo trial.