An LC-MS/MS method for the simultaneous determination of chlorogenic acid, forsythiaside A and baicalin in rat plasma and its application to pharmacokinetic study of Shuang-huang-lian in rats

An LC-MS/MS method was developed for the simultaneous determination of chlorogenic acid, forsythiaside A and baicalin, three major ingredients in Shuang-huang-lian preparations, in rat plasma. Following extraction by methanol-ethyl acetate-trifluoroacetic acid (49:49:2, v/v/v), the extracted analytes were separated on a reverse phase C12 column using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. The limits of quantification were between 1.0 and 2.1 ng/mL, the precision was <7% and the accuracy was between 94% and 107%. The validated method was applied to a comparative pharmacokinetic study in rats after administration of Shuang-huang-lian solutions via intravenous, peroral or intratracheal routes. The results showed that the three chemical markers were more rapidly and thoroughly absorbed following pulmonary delivery as compared with peroral administration. (C) 2010 Elsevier B.V. All rights reserved.