Baicalensis Contiguous Quality Control Methods And Pharmacokinetic Studies

Qinlian tablet, which is composed of six herbs: Scutellaria baicalensis Georgi, Forxythia suspensa (Thunb.) Vahl, Coptis chinensis Franch, Phellodendron chinense Schneid., Paeonia lactiflora Pall and Glycrrhiza uralensis Fisch. In the clinical practice of traditional Chinese medical science, the tablet has been used to treat cephalalgia, sore, and infection of the peogaster system disease over a very long period of time and has produced a quite good effect. It was listed in the Drug Standard of Ministry of Public Health of the People's Republic of China. In Chp 2005 baicalin, berberine hydrochloride and paeoniflorin in Qinlian tablet were identified by TLC, baicalin in Qinlian tablet was determined by HPLC.In this paper, baicalin and berberine hydrochloride were identified in Qinlian tablet simultaneously. Above method provided a qualitative and quantitative basis for the quality standard of Qinlian tablet, with the posts clear, reproducible and only.RP-HPLC methods were established to determine the contents of baicalin, baicalein, wogonin, palmatine hydrochloride, berberine hydrochloride, paeoniflorin and glycyrrhizic acid in Qinlian tablet. The determination could be accomplished by different mobile phase system in Diamonsil C₁₈ columns. The linear ranges were 36.8 - 368.0μg·mL^-1(r = 0.999 7), 1.75 - 17.5μg·mL^-1(r= 0.999 8), 1.5- 15.0μg·mL^-1(r = 0.999 9), 5.2 - 52.0μg·mL^-1(r= 0.999 8), 30.4- 304.0μg·mL^-1(r = 0.999 7), 5.8 - 58.0μg·mL^-1(r = 0.999 8) and 7.4 - 74.0μg·mL^-1(r = 0.999 4), respectively. The recoveries were 97.3 %(RSD = 1.8 %), 101.1 %(RSD = 1.8 %), 99.0 %(RSD = 2.0 %), 100.1 %(RSD = 1.1 %), 99.9 %(RSD = 0.8 %), 100.5 %(RSD = 2.0 %) and 100.1 %(RSD = 1.8 %), respectively. The assay methods are simple, rapid and reproducible, which provide a quantitative basis for the quality assessment of Qinlian tablet.A HPLC-UV method was developed for the determination of baicalin in rat plasma. The analysis was performed on a Diamonsil^TMC₁₈ (200 mm×4.6 mm, 5μm) column with acetonitrile-0.1% phosphonic acid (27:73, v/v) as the mobile phase at the flow rate of 1.0 mL·min^-1 .The UV detection wavelength was set at 277 nm. The extraction recoveries at the concentration of 0.300, 3.00 and 12.0μg·L^-1 were 64.3 %, 71.1 % and 67.8 %, respectively. A linear calibration was obtained in the concentration range from 0.120 to 15.0μg·mL^-1(r≥ 0.998 2). Intra-day RSD and inter-day RSD were both less than 14.5 %. The method was proved to be accurate and simple, and was applied to the pharmacokinetic study of baicalin of Radix Scutellariae decoction and Qinlian tablet in rats . The pharmacokinetic parameters were achieved as follows: C_max 2.429±0.594μg·mL^-1, T_max 1.250±2.333 h, t_1/2β 9.744±4.556 h, AUC_0-t 21.51±7.22μg·h·mL^-1, AUC_0-∞ 24.02±9.66μg·h·mL^-1; and C_max 0.931±0.265μg·mL^-1, T_max 9.000±0.894 h, t_1/2β 6.545±1.943 h, AUC_0-t 14.42±3.01μg·h·mL^-1, AUC_0-∞15.04±3.31μ·h·mL^-1, respectively.