Mobile phase, Diluent, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Docusate Sodium Capsules.

Assay preparation— Transfer an accurately measured volume of Solution, equivalent to about 100 mg of docusate sodium, to a 100-mL volumetric flask, dilute with Diluent to volume, and mix. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with Diluent to volume, and mix. Pass this solution through a filter into a vial, discarding the first 6 mL of the filtrate.

Procedure— Proceed as directed for Procedure in the Assay under Docusate Sodium Capsules. Calculate the quantity, in mg, of C20H37NaO7S in each mL of the Solution taken by the formula: in which V is the volume, in mL, of Solution taken; and the other terms are as defined therein.