Determination of isosorbide dinitrate in pharmaceutical products by HPLC.

A high-performance liquid chromatographic (HPLC) assay for isosorbide dinitrate in pharmaceutical formulations is described. The method employs a reversed-phase C18 column with a mobile phase containing methanol/water/acetate buffer and is specific for isosorbide dinitrate with respect to its 2- and 5-mononitrate degradation products and other organic polynitrate esters. The method is applicable to the analysis of the diluted bulk drug and dosage forms, including sublingual, oral, chewable, and timed-release preparations.