Quantitation of hydroxyprogesterone caproate, medroxyprogesterone acetate, and progesterone by reversed-phase high-pressure liquid chromatography.

A high-pressure liquid chromatography method for the quantitation of hydroxyprogesterone caproate, medroxyprogesterone acetate, and progesterone in pharmaceutical dosage forms was developed. The method gave accurate, precise, and reproducible results. The excipients present in the dosage forms did not interfere with the assay procedure except benzyl benzoate in progesterone injection. The percent relative standard deviations based on six injections were 1.6, 2.5, 2.7% for hydroxyprogesterone caproate, medroxyprogesterone acetate, and progesterone, respectively. The stability of progesterone in ethanol--propylene glycol--water (10:50:40) was studied. The loss in potency of progesterone, even after 487 days of storage at 50 degrees, was less than 10%.