The paper is to report the observation of pharmacokinetic changes of the characteristic ingredients in the combinations of different-dose herbs of Shaoyao-Gancao decoction. After the establishment of HPLC analytical method of plasma effective constituents, rats were orally administered with different-dose herbs of Shaoyao-Gancao decoction. Blood samples at different times after administering these decoctions were collected, and then were analyzed by HPLC fingerprints technology. Pharmacokinetic parameters of characteristic peaks were analyzed by SPSS 15.0 software and DAS 2.0. At last, we looked for the correlation of those pharmacokinetic parameters and the dosage of Gancao. The best dose of Shaoyao-Gancao decoction was at the ratio of 4 to 4, which was consistent with the dose commonly used in ancient times. The absorption of characteristic peaks from Shaoyao-Gancao decoction was related with the dosage of Gancao, and there existed interaction between each characteristic ingredients. There existed the right dose-ratio of Shaoyao and Gancao to get the best effect. The absorptions of effective constitutents were mutual waxing and waning in order to increase biological effects together. It's demonstrated the compatibility connotation at a right dose-ratio of Shaoyao-Gancao decoction through the angle of pharmacokinetics.

OBJECTIVETo observe the pharmacokinetic effect of Shaoyao Gancao compound on rats using different decocting methods, and to pharmacokinetically detect the the compatibility of the component compounds of the Shaoyao Gancao compound from the pharmacokinetic viewpoint.

METHODBased on the established HPLC analytical method of plasma effective constituents, rats were orally administered with a single or mixed decoction of Shaoyao and Gancao. Blood at different times after administering these decoctions were collected, and then variance analysis was made for pharmacokinetic parameters.

RESULTThe results of all six rats indicated that the absorption of the mixed decoction of Shaoyao and Gancao was greater than that of the single decoction. While, the absorption of the characteristic peaks at the retention time of 5.2, 11.0, 12.0, 14.6 min had statistical significance.

CONCLUSIONShaoyao Gancao compound was proved better than that of the single decoction from the pharmacokinetic viewpoint.

Administration, Oral ; Animals ; Biological Availability ; Chromatography, High Pressure Liquid ; Drug Compounding ; methods ; Drugs, Chinese Herbal ; administration & dosage ; analysis ; pharmacokinetics ; Male ; Paeonia ; chemistry ; Plasma ; chemistry ; Rats ; Rats, Sprague-Dawley