for oral solution packaged in single-unit containers: meets the requirements.

for oral solution packaged in multiple-unit containers: meets the requirements.

Internal standard solution, Standard solution, Standard preparations, Chromatographic system, and System suitability and standard curve— Proceed as directed in the Assay under Isosorbide Concentrate.

Assay preparation— Transfer an accurately measured volume of Oral Solution, equivalent to about 450 mg of isosorbide, to a 250-mL volumetric flask, add 25.0 mL of Internal standard solution, then add water to volume, and mix.

Procedure— Proceed as directed for Procedure in the Assay under Isosorbide Concentrate. Calculate the quantity, in mg, of isosorbide (C6H10O4) in each mL of the Oral Solution taken by the formula: in which C is the concentration, in mg per mL, of isosorbide in the Assay preparation found by reference to the Standard curve; and V is the volume, in mL, of Oral Solution taken.