Compatibility Studies of Sildenafil with Different Excipients by Using TGA, DSC, XRD and FTIR

Abstract

Study of drug–excipient interactions is a crucial step in preformulation stage of drug development toachieve consistent chemical, physical, bioavailability, manufacturability and stability of the dosage form.In pre-formulation studies, it is important to use thermoanalytical and spectroscopic methods. These areimportant systems for achieving a suitable formulation. Sildenafil is a well-tolerated and highly effectivetreatment for erectile dysfunction. Erectile dysfunction was revolutionized with the development of aselective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5.Thermogravimetric analysis, Differential Scanning Calorimetry, Fourier TransformInfrared Spectroscopy, and X-ray Powder Diffraction systems were used in the investigation and todetermine the possible interactions between sildenafil and some excipients like butylated hydroxyanisole,cellulose, sodium carboxymethyl cellulose, ascorbic acid, and citric acid. Binary mixtures ofdrug:excipient=1:1 (mass/mass) have been analyzed. According to the results, there is incompatibilitywith butylated hydroxyanisole, ascorbic acid, and citric acid.