Determination of prednisolone and prednisone in plasma, whole blood, urine, and bound-to-plasma proteins by high-performance liquid chromatography.

A high-performance liquid chromatographic technique for the simultaneous determination of prednisolone and prednisone in human plasma, whole blood, urine, and bound-to-plasma proteins, using betamethasone as internal standard, is presented. Liquid-liquid extraction is used for whole blood samples, and solid phase extraction is used for plasma, urine, and proteins bound to plasma. The accuracy, precision, specificity, linearity, and repeatability meet the requirements of current recommendations in bioanalytical method validation. The method is suitable for high altitude pharmacokinetic studies, in which the quantitation of drugs in those fluids is required. The results from healthy volunteers are presented.