SIMULTANEOUS DETERMINATION OF PREDNISOLONE, PREDNISOLONE ACETATE AND HYDROCORTISONE IN HUMAN SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A method for the simultaneous determination of prednisolone, prednisol one acetate and hydrocortisone has been established to monitor the ser um levels of these three compounds in healthy volunteers following int ramuscular 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 LiChros orb 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 prednisolone (C.V. = 14.7%, n = 6) and 5.0 ng/ml for predn isolone 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 stand ard are provided. The results of quality control samples determined du ring routine analysis (n = 114) are presented. Serum levels of the com pounds after intramuscular administration of 25 mg of prednisolone ace tate are discussed.