Studies on Preparation of Candesartan Solid Dispersion and Its Dissolution and Stability

OBJECTIVE To improve the solubility of candesartan by using solid dispersion(SD) technology. METHODS Single factor method and orthogonal experimental method were adopted to obtain the optimal formula by using the in vitro dissolution as an index. FTIR, DSC, XRD were used to study the existing status of candesartan in SD and bond between candesartan and carriers, so as to study solubilizing mechanism and the stability. RESULTS The ideal candesartan SD was prepared under the condition as follows, carrier was PVPK30 and the solvent volume ratio was methylene chloride : methanol : ethanol=2︰2︰1. The dissolution of the candesartan SD is up to 99% in one hour. XRD and DSC results showed that drug exists in crystallite or amorphous form in SD. FTIR results indicated that hydrogen bonds were formed between drug and PVPK30. Accelerated stability tests demonstrated that stability of SD was well in 30 days. CONCLUSION SD technology can obviously improve dissolution of candesartan. Candesartan SD is a stabilizing system which having actual applied value.