Studies on Preparation and Dissolution of Oridonin Solid Dispersions

OBJECTIVE To prepare and characterize the solid dispersions (SDs) with improved solubility and dissolution rates of oridonin. METHODS The SDs were prepared with polyethyleneglycol 6000 (PEG6000) and polyvinylpyrrolidone K30 (PVPK30) as carriers respectively. UV-spectrophotometry was used to determine the contents of oridonin. The physical and chemical properties of SDs, starting material and physical mixtures were investigated by differential thermal analysis (DTA) and dissolution rate in vitro. The solubilities were studied. RESULTS It was found that the solubility and dissolution rates of oridonin were enhanced for the formation of SDs. Oridonin exists in a highly dispersed state in the carriers. CONCLUSION The SDs prepared with PVPK30 can increase the solubility and dissolution rate of oridonin remarkablely.