Simultaneous determination of prednisolone, prednisolone acetate and hydrocortisone in human serum by high-performance liquid chromatography

A method for the simultaneous determination of prednisolone, prednisolone acetate and hydrocortisone has been established to monitor the serum levels of these three compounds in healthy volunteers following intramuscular administration of prednisolone acetate. Serum samples of 0.75 ml were extracted with ethyl acetate after addition of the internal standard, dexamethasone. The compounds were separated using a LiChrosorb Si 60 column and detected by UV absorbance. Specificity, linearity, as well as the repeatability, intermediate-precision and accuracy of the method were established. The lower limit of quantification was 2.0 ng/ml for prednsolone (C.V. = 14.7%, N=6) and 5.0 ng/ml for prednisolone acetate (C.V. = 13.9%, N= 6 and hydrocortisone (C.V. = 11.7%, N=6). Data on the recovery of the compounds and the internal standard are provided. The results of quality control samples determined during routine analysis (n = 114) are presented. Serum levels of the compounds after intramuscular adminstration of 25 mg of prednisolone acetate are discussed.