Sustainable and smart HPTLC determination of silodosin and solifenacin using a constructed two illumination source chamber with a smartphone camera as a detector: Comparative study with conventional densitometric scanner

Abstract

The tremendous revolution in the built-in digital camera of smartphones has opened new horizons for its applicability as a portable, easily accessible, and user-friendly detector in different analytical techniques. In this article, we proposed and developed a new and inexpensive detector for simultaneous analysis of silodosin and solifenacin. The innovation makes use of a smartphone camera coupled with high-performance thin layer chromatographic (HPTLC) approach. Firstly, chromatographic separation was attained using HPTLC plates with an ecofriendly mobile phase composed of ethyl acetate, ethanol & 25% w/w ammonia (3.0: 7.0: 0.3, by volume). The developed plates were then visualized using Dragendorff's reagent and then photographed via smartphone's rear-facing camera fixed on a fabricated two-illumination source chamber. The intensities of drug spots were quantified using an open-source image analysis software, ImageJ, over concentration ranges of 2.0–30.0 μg/band. Moreover, the study was extended to compare the obtained results with a benchtop densitometric method at 215.0 nm where the densitometric one gave linear response ranging from 0.1 to 7.0 μg/band for silodosin and 0.1–6.0 μg/band for solifenacin. The fast, simple, reliable and green merits of the proposed HPTLC/smartphone method promted it as an excellent platform for assaying marketed combined tablets and assuring their content uniformity. Moreover, the high sensitivity of the densitometric method was exploited, for the first time, for determining the residual content of the cited drugs on manufacturing equipment surfaces during cleaning validation. Finally, the environmental impact of the methods was appraised via three state-of-the-art greenness metrics.