A pre-clinical pharmacokinetic study in rats of three naturally occurring iridoid glycosides, Picroside-I, II and III, using a validated simultaneous HPLC-MS/MS assay.

•The determination of Picroside-I, II and III in rat plasma and tissue by LC-MS/MS.•The LLOQ for three analytes is 0.5ng/ml in all biological fluids.•The method was used to a preclinical pharmacokinetics and tissue distribution study.•Higher level of Picroside-II was found in liver tissue.•Picroside-I and II could cross the blood–brain barrier and the blood-testis barrier.