Pharmacokinetic comparisons of albiflorin and paeoniflorin after oral administration of Shaoyao-Gancao-Tang and single herb Paeony decoction to rats.

Shaoyao-Gancao-Tang (SGT) is a traditional Chinese prescription containing Radix Paeoniae alba and Radix Glycyrrhizae and is commonly used to relieve pains. Albiflorin and paeoniflorin are the main effective compounds of Radix Paeoniae alba, and the pharmacokinetic differences of the two compounds in rats after oral administration of SGT and single herb Paeony decoction were studied. At different time points (5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360, and 540 min) after administration, plasma concentrations of albiflorin and paeoniflorin were determined using a simple and reliable UPLC method, and main pharmacokinetic parameters were evaluated. It was found that there were significant differences (p < 0.05 or p < 0.01) between the two groups. The results indicated that some components in the other ingredient herb of SGT (Radix Glycyrrhizae) had a pharmacokinetic interaction with albiflorin and paeoniflorin and hence reduced their systematic exposure level.