Comparative pharmacokinetics study of five alkaloids in rat plasma and related compound-herb interactions mechanism after oral administration of Shuanghua Baihe tablets.

Shuanghua Baihe tablet is a traditional Chinese patent medicine which showed special advantages in the treatment of recurrent aphthous stomatitis. Scientists have improved and implemented the LC-MS/MS method, which is specific and sensitive, for comparative pharmacokinetics study of five alkaloids, including palmatine, berberine, epiberberine, jatrorrhizine and coptisine in rat plasma after oral administration of Rhizoma Coptidis extract and Shuanghua Baihe tablets. The results showed that Shuanghua Baihe tablets could promote the absorption of these five alkaloids and improved their bioavailability compared with R. Coptidis extract. To further investigate the related mechanism, everted intestinal sac model in vitro was used to indicate that alteration of in vivo pharmacokinetics of five alkaloids could be attributed to, at least in part, the absorption changes by coadministration of other herbs. These discoveries served as a theoretical basis for clinical use of Shuanghua Baihe tables.