Validated Chromatographic and Spectrofluorimetric Methods for Analysis of Silodosin: A Comparative Study with Application of RP-HPLC in the Kinetic Investigation of Silodosin Degradation.

Background: Stability indicating determination of pharmaceuticals is crucial, especially for drugs which have few published official analytical methods. Silodosin (SLD) is an FDA approved α1A-adrenoceptor blocker.

Objective: Efficient analytical methods were suggested, based on different instrumental techniques for quantification of SLD, besides conducting kinetic investigation of its degradation.

Validated stability-indicating spectrophotometric methods for the determination of Silodosin in the presence of its degradation products.

Five simple, rapid, accurate, and precise spectrophotometric methods are developed for the determination of Silodosin (SLD) in the presence of its acid induced and oxidative induced degradation products. Method A is based on dual wavelength (DW) method; two wavelengths are selected at which the absorbance of the oxidative induced degradation product is the same, so wavelengths 352 and 377 nm are used to determine SLD in the presence of its oxidative induced degradation product. Method B depends on induced dual wavelength theory (IDW), which is based on selecting two wavelengths on the zero-order spectrum of SLD where the difference in absorbance between them for the spectrum of acid induced degradation products is not equal to zero so through multiplying by the equality factor, the absorption difference is made to be zero for the acid induced degradation product while it is still significant for SLD.