Stress degradation studies of nelfinavir mesylate by Fourier transform infrared spectroscopy.

Nelfinavir mesylate is the first nonpeptidic protease inhibitor available in pediatric formulation. In the present paper the stability of nelfinavir mesylate under different stress conditions is evaluated using Fourier transform infrared spectroscopy. The drug is subjected to thermal degradation, photodegradation, acid hydrolysis, base hydrolysis and oxidation as per ICH guidelines. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and high performance liquid chromatography (HPLC) are carried out to support the implementation of infrared spectroscopy for the stability studies of nelfinavir mesylate. Significant changes are observed in the IR spectra collected after exposing the drug to thermal radiations, acid and base hydrolysis and oxidative degradation. No change is observed in the spectra of the drug after exposing it to sunlight indicating the good photostability of nelfinavir mesylate. The results of infrared spectroscopy agree well with that of other complementary techniques as DSC, TGA, XRD and HPLC.