Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system— Prepare as directed in the Assay under Hydrocortisone Valerate.

Assay preparation— Transfer an accurately weighed quantity of Ointment, equivalent to about 1 mg of hydrocortisone valerate, to a screw-capped tube. Add 8.0 mL of a mixture of methanol and water (3:1), and swirl to disperse. Heat in a steam bath until melted (about 30 seconds), swirl again, and allow to cool at room temperature. Add 2.0 mL of Internal standard solution, and mix. Centrifuge for 5 minutes, and filter the supernatant, if necessary, to obtain a clear solution.

Procedure— Proceed as directed in the Assay under Hydrocortisone Valerate. Calculate the quantity, in mg, of hydrocortisone valerate (C26H38O6) in the portion of Ointment taken by the formula: in which the terms are as defined therein.