Analysis of Ursodeoxycholic Acid Using Ultra-performance Liquid Chromatography with Tandem Mass Spectrometry

Background: A fast and reliable method for the quantification of ursodeoxycholic acid (UDCA) in hepatic function medicines was developed. Objective: To develop and validate a simple cleanup procedure based on a solid-phase extraction using an OASIS HLB cartridge for extracting ursodeoxycholic acid and its internal standard, dehydrocholic acid, from pharmaceutical formulations. Methods: Resoluble separation of both analytes through isocratic ultra-performance liquid chromatography with a reversed- phase ACQUITY CSH C18 column was carried out within 5 min. Results: The recovery rates of the newly developed procedure were 95 ± 4% for ursodeoxycholic acid and 91 ± 4% for dehydrocholic acid. Using electrospray ionization-ion trap tandem mass spectrometry, the intra- and inter-day precision values were determined to be <4.5%, whereas accuracy ranged from 90.4 to 95.3%. The ursodeoxycholic acid contents in three different samples (two from a soft capsule and one from a tablet) obtained by the established analytical tool were analogous to the ursodeoxycholic acid contents indicated on the labels of the pharmaceuticals. In addition, analysis of ursodeoxycholic acid in human plasma with the newly developed method was validated, revealing the method to be the most sensitive of all reported UDCA bio-analytical tools. Finally, the validated protocol was successfully applied to a comparative bioavailability study of ursodeoxycholic acid tablets. Conclusion: The newly developed UPLC-ESI-MS/MS method is the most sensitive bio-analytical tool available for UDCA analysis. The UPLC-ESI-MS/MS method can be utilized in studies of the pharmacokinetics and bioavailability of bile acids such as UDCA.