ABSTRACT
This study was aimed to determine the solubility an d oil-water partition coefficient of main active com-ponents in Ge-Gen Qin-Lian (GGQL) Tablets (puerarin, baicalin and berberine hydrochloride) in phosphate buffer solution of different pH values and under the background of many components. Solubility of puerarin, baicalin and berberine hydrochloride in different medium pH, and oil-water partition coefficient of the octanol-water and oc-tanol-buffer system were determined by HPLC method. The results showed that the solubility and oil-water partition coefficient of puerarin, baicalin and berberine hydrochloride were varied with the change of pH, and varied under the background of components. At pH 7.4, the solubility was the biggest;puerarin was 7.56 mg·mL-1;baicalin was 17.07 mg·mL-1; berberine hydrochloride was 3.57 mg·mL-1. Oil-water partition coefficient P of these components at pH 1.0 was bigger;puerarin was 0.420 (lgP=-0.38);baicalin was 10.783 (lgP=1.03);berberine hydrochloride was 0.267 (lgP=-0.57). It was concluded that lipid solubility of puerarin, baicalin and berberine hydrochloride at pH 1.0 was better. It was speculated that better absorption in the stomach, and low lipid solubility under other pH. It was speculated that lipid solubility may be one of the reasons affecting the intestinal absorption.