Determination of Caudatin in Rat Plasma by UPLC-MS/MS: Application to a Preclinical Pharmacokinetic Study

In this study, a simple, sensitive, and robust analytical method based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of caudatin in rat plasma using carbamazepine as internal standard (IS). This method was linear over the concentration range 2.5-300 ng/ml with a lower limit of quantification (LLOQ) of 2.5 ng/ml. Inter- and intra-day precision (RSD%) were all within 10% and the accuracy (RE%) was equal or lower than 5%. Recoveries of caudatin and IS were more than 80% and matrix effects were not significant. Stability studies showed that caudatin was stable under a variety of storage conditions. The method was successfully applied to a pharmacokinetic study involving oral administration of caudatin to rats.