Preparation And Evaluation Of Silymarin Suspension

With the preparation of silymarin suspension (Suspension), in this study, it was to solve the problem of its low solubility, of its stow dissolution, and of its low bioavailability so as to improve its application. Silymarin suspension was prepared by grind method, glycerol used as wetting agent, carboxymethyl cellulose sodium (CMC-Na) as suspending agent, use polyvinylpyrrolidone (PVP) to increase drug released degree in gastric juice and intestinal juice, to improve bioavailability. Based on the sedimentation volume, viscosity, redispersibility, flocculation and cumulative percent released, the optimized formulation was selected. Compared Suspension with Legalon Suspension (LGL), the cumulative percent released was 52% and 21% in artificial gastric juice in 90 minutes respectively, 84% and 27% in artificial intestinal juice in 90 minutes respectively. According to the light and heat stable test, light stability of silymarin suspension was not so well, but it didn抰 affect the content of silybin in preparation and assaying. In this study, propylparaben was used as internal -3- standard, a suitable reverse-phased high performance liquid chromatographic method for the quantitative determination of silybin in rat plasma was used, and silybin was calculated as free silybin. Standard curves showed a good linear relationship in the plasma over the concentration range 0.25 i-i g/ml 憕 10.00 i-i. gIml. Recovery was found to be quantitative, the coefficients of variance were good for within day and between days. The lowest concentration value (0.25 11 g/ml) was considered as the limits of content. Compared the pharmacokinetic parameters of silybin in rat plasma after single equimolar oral does (200 ~I gIml, expressed as silybin equivalents) of Suspension and LGL, area under the curve (AUC) was 14.23 he 1~t gIml and 9.5 i-~ gIml respectively, the relative bioavailability of Suspension was 148.54%, Two preparations had the similar T max, of 0.50 hour, Cmax of Suspension was 9.68 t.i g/ml, more higher than that of Legalon抯, 4.15 ~t gIml, the T112 were 3.857 and 3.560 hour in rat plasma.