RESUMO
OBJECTIVE: To study in situ intestinal absorption kinetics of baicalin contained in Tiangou Jiangya capsules, and the effect of different intestinal segments, pH value, drug concentration and P-gp inhibitor on the absorption. METHOD: The in situ intestinal perfusion test was adopted, and HPLC method was used to determine the content of baicalin in samples at different time points. Ultra-violet (UV) spectrophotometry was used to determine the content of phenol red in samples at different time points. RESULT: When pH value was at 5. 0, 6. 5, 7. 4, the absorption of baicalin was not impacted. P-gp inhibitor verapamil could enhance the absorption of baicalin. When the quality concentration of the test solution ranged between 5-20 g L -1 , the linearity of the absorption amount of baicalin increased. The absorption kinetic equation of baicalin was Y = -0. 073 7X +0. 118 7 (r = 0. 994 8) , K. 0. 073 7 h -1 , t1/2 9. 40 h. CONCLUSION: Baicalin is mainly absorbed in colon. The absorption of baicalin shows the first-order kinetics process, with the absorption mechanism of passive diffusion. Baicalin is a substrate for P-gp.
Assuntos
Álcoois Benzílicos/química , Flavonoides/química , Flavonoides/metabolismo , Furanos/química , Glucosídeos/química , Absorção Intestinal , Lignanas/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Álcoois Benzílicos/normas , Feminino , Flavonoides/normas , Furanos/normas , Glucosídeos/normas , Concentração de Íons de Hidrogênio , Absorção Intestinal/efeitos dos fármacos , Cinética , Lignanas/normas , Masculino , Controle de Qualidade , Ratos , Ratos Wistar , Verapamil/farmacologiaRESUMO
A method for the quantification of salidroside, a major biologically active compound in Rhodiola, in rat plasma by on-line SPE LC/MS/MS in negative electrospray mode was developed and validated. A column-switching instrument and two HPLC pumping systems were employed, and salicin was used as the internal standard. A Waters Oasis HLB extraction column and an Agilent TC-C(18) analytical column in a column-switching set-up with gradient elution were utilized. The MS/MS ion transitions monitored were m/z 299.0/119.0 and 285.1/122.9 for salidroside and salicin, respectively. The standard curves were linear within a range of 50-5000 ng/mL using weighted linear regression analysis (1/x). The intra- and inter-day coefficients of variance ranged from 1% to 9%. The recovery was above 90%. The freeze/thaw and long-term stability were validated. This method was subsequently applied to a pharmacokinetic study of salidroside in rats.
