Leuco crystal violet method for the determination of nicorandil in bulk dosage

Two simple, sensitive and validated spectrophotometric methods have been described for the assay of nicorandil in drug formulations. Method A is based on the determination of nicorandil by using leuco crystal violet (LCV). Nicorandil liberates nitrite on reaction with Zn and NH4Cl, which reacts with acidified KI to liberate iodine, which reacts with LCV to form crystal violet (CV). The calibration graphs were linear over the concentration ranges 0.1 μgmL−1–2.0 μgmL−1& 0.2 μgmL−1–4.0 μgmL−1 respectively. The absorbance of which is measured at 592 nm. Another method is based on diazotization of p-amino acetanilide by liberated nitrite followed by coupling with orcinol, which shows maximum absorbance at 458 nm. The optimum conditions and other analytical parameters were evaluated. The proposed methods have been applied successfully to the analysis of nicorandil in pure form and its dosage forms and no interference was observed from common excipients present in pharmaceutical formulations.