Simultaneous measurement of prednisone, prednisolone and hydrocortisone in plasma by high performance liquid chromatography.

The authors describe a normal phase liquid chromatographic assay suitable for therapeutic monitoring of prednisone, prednisolone, hydrocortisone in human and animal plasma. The compounds were extracted into dichloromethane using flumethasone as internal standard. The separation was obtained by using a silica normal phase (5 mu) and a mobile phase of dichloromethane, methanol, acetic acid (95.6; 4; 0.4 v/v/v). The absorbance of the compounds was monitored at 254 nm with a sensitivity limit of 2 ng/ml for all the products. This method was applied to pharmacokinetic studies in animal and therapeutic monitoring in man.