Simultaneous identification of prednisolone and its ten metabolites in human urine by high performance liquid chromatography-tandem mass spectrometry.

The use of prednisolone and prednisone is prohibited by the World Anti-Doping Agency (WADA) due to their performance-enhancing effect. The purpose of the present work was to explore the possibility of identification and detection of various metabolites of prednisolone by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in excretion study samples. Ten metabolites of prednisolone could be identified namely prednisone (11-oxo metabolite) [M-1], 6-β-OH-prednisolone [M-2], 20-β-OH-prednisolone [M-3], 20-α-OH-prednisolone [M-4], 20-α-OH-prednisone [M-5], 20-β-OH-prednisone [M-6], 2 tetrahydro epimers of 20-β-OH-prednisolone [M-7], 2 tetrahydro epimers of 20-α-OH-prednisolone [M-8], 2 tetrahydro epimers of 20-β-OH-prednisone [M-9], and 2 tetrahydro epimers of 20-α-OH-prednisone [M-10]. Prednisolone was administered in 10-, 20-, and 40-mg dosage to healthy volunteers to study detection of various metabolites. The parent, M-1, M-2, and M-3 could be detected up to 72 h while rest of the metabolites were detectable up to 24 h after drug administration. The detection of newer metabolites of the drug can further be used for confirmatory purposes.