Studies On The Absprption Of Puerarin In Rats' Intestines And Formulation Strudies On Gastric Retention Dosage Forms

Absorption kinetics of puerarin in rats' intestines was studied. Puerarin in small intestinal solutions were determined by dual- λ UV. Puerarin solutions were circulated for 4 hours in the rat's small intestine. At different concentrations of puerarin 50, 100, 200 μg/mL, the intestinal absorption rate constants K_a were 0.021, 0.030, 0.020 h^-1, and absorption percentage Pa were 19.28%, 21.78% , 16.98%, respectively. The rat intestinal absorption experiments (in situ) showed the absorption of puerarin was a first-order process and the mechanism of absorption was passive diffusion transport.The effects of some surfactants on absorption of puerarin in rat intestine were investigated. The surfactants were added in puerarin solution before the intestinal circulation. The results indicated that all the used surfactants had positive enhancement on the absorption of puerarin. With 1% poloxamer in 50 μg/mL puerarin solution, the intestinal absorption percentage was 35%, which was significantly increased than that of control.Puerarin solid dispersions were prepared by melting and solvent evaporation method. DSC and FT-IR were used to determine the state of...