New methods for the assay of 5-isosorbide mononitrate and its validation.

Differential scanning calorimetry (DSC) is a method which has been applied to obtain thermal information about both raw material and the determination of the content of 5-ISMN in dry mixtures with lactose. The main advantage this offers, compared to other methods, is that it is not necessary to use a standard, it only being necessary to know the data of its fusion heat. HPLC and TLC-densitometry are considered for the determination of 5-ISMN: lactose and pharmaceutical dosage forms. Linearity test, repeatability and accuracy were satisfactory in both methods. Recovery data in pharmaceutical formulations (expressed as the percentage of the label claim) from HPLC and TLC did not give any significant difference (P = 95%). The results show that the chromatographic methods are simple, fast and reliable procedures for the determination of 5-ISMN.