Test specimen— Transfer about 25 mg of Injectable Suspension to a centrifuge tube, add 20 mL of water, and shake well. Centrifuge, and discard the liquid layer. Repeat this washing step with three additional 20-mL portions of water. Dry the material so obtained at 105 for 3 hours.

Mobile phase, Diluent, Internal standard solution, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Isoflupredone Acetate.

Assay preparation— Transfer an accurately measured volume of Injectable Suspension, equivalent to about 4 mg of isoflupredone acetate, to a suitable container. Add 8.0 mL of Internal standard solution and 32.0 mL of Diluent, and swirl to dissolve.

Procedure— Proceed as directed for Procedure in the Assay under Isoflupredone Acetate. Calculate the quantity, in mg, of isoflupredone acetate (C23H29FO6) in each mL of Injectable Suspension taken by the formula: in which V is the volume, in mL, of Injectable Suspension taken to prepare the Assay preparation; and the other terms are as defined therein.