High-pressure liquid chromatographic evaluation of aqueous vehicles for preparation of prednisolone and prednisone liquid dosage forms.

A high-pressure liquid chromatographic method was developed that separates prednisolone from prednisone, prednisone from methylprednisolone succinate sodium, and hydrocortisone from hydrocortisone acetate or cortisone acetate. The common liquid dosage preservatives methylparaben, propylparaben, and sodium benzoate do not interfere with quantitative prednisolone, prednisone, and hydrocortisone determinations. The method was used to study prednisolone and prednisone stability in five aqueous vehicles (water, citrate buffer USP, 50% glycerin, 50% sorbitol, and 50% sucrose) containing 10% (v/v) ethanol. Prednisone crystallized out in all vehicles except glycerin, in which it appeared to be stable for at least 92 days. Prednisolone did not crystallize in any vehicle but decomposed quickly in citrate buffer. Sorbitol and glycerin appeared to be the best vehicles for prednisolone. The developed method was applied successfully to the quantitative determinations of prednisolone, prednisone, and hydrocortisone in commercial tablets.