Simultaneous Determination of Ten Bioactive Components from Shenling Baizhu San in Rat Plasma by UHPLC-MS/MS: Application to a Comparative Pharmacokinetic Study in Normal and Two Models of Ulcerative Colitis Rats.

Shenling Baizhu San, a traditional formula, has a long history of treating spleen asthenic diarrhea by invigorating the spleen and dispelling dampness in China. A rapid and accurate UHPLC-MS/MS method was developed and fully validated for the simultaneous determination of ten active constituents in rat plasma: panaxadiol, ginsenoside Rg1, atractylenolide I, atractylenolide III, pachymic acid, neferine, nuciferine, diosgenin, platycodin D, and isoliquiritigenin. The plasma samples were pretreated by the protein precipitation method with acetonitrile. The analytes and puerarin (internal standard) were determined with high selectivity and sensitivity (LLOQ, 0.31-0.68 ng·mL) within 10 minutes. The validation parameters, including intra-/interday precisions, accuracy, recovery, matrix effect, and stability, were within acceptable ranges. The validated method was successfully applied to the pharmacokinetics study of ten components in normal and two rat models of ulcerative colitis (i.e., spleen deficiency with dampness retention-ulcerative colitis (SDDR-UC) rats and pure-ulcerative colitis (P-UC) rats). The pharmacokinetic parameters were significantly different among the three groups of rats. Overall, the absorption of the components was shown as follows: normal group > SDDR-UC group > P-UC group. The study could provide a scientific basis for further studies on pharmacokinetics and clinical differential application of SDDR-UC and P-UC patients.