Smartphone as a Portable Detector for Thin-Layer Chromatographic Determination of Some Gastrointestinal Tract Drugs

Abstract

Thin-layer chromatography (TLC) is an effective and simple technique for screening, evaluating, and quantifying low-quality and counterfeit pharmaceutical products. Smartphones have recently been used as accessible, cheap, and portable detectors that can replace more complicated analytical detectors. In this work, we have developed a simple and sensitive TLC method utilizing a smartphone charged-coupled device (CCD) camera not only to verify and quantify some gastrointestinal tract drugs, namely, loperamide hydrochloride (LOP) and bisacodyl (BIS), but also to detect acetaminophen (ACT) as a counterfeit drug. Both drugs (LOP and BIS) were chromatographed separately on a silica gel 60 F 254 plate as a stationary phase under previously reported chromatographic conditions, using ethyl acetate:methanol:ammonium hydroxide (24:3:1, by volume) and ethyl acetate:methanol:glacial acetic acid (85:10:5, by volume) as developing systems to determine LOP and BIS, respectively. Universal stains, namely, iodine vapors and vanillin, were used to visualize the spots on the TLC plates to get a visual image using the smartphone camera and a spotlight as an illumination source with no need for a UV illumination source. The spot intensity was calculated using a commercially available smartphone application for quantitative analysis of the studied drugs utilizing ″acetaminophen″ as an example of a counterfeit substance. R f values were calculated using the recorded images and found to be 0.77, 0.79, and 0.74 for LOP, BIS, and ACT, respectively, providing drug identity. Linear calibration curves using the smartphone–TLC method were obtained between the luminance and the corresponding concentrations over the ranges of 2.00–10.00 μg/mL and 1.00–10.00 μg/mL with limits of detection of 0.57 and 0.10 μg/mL for LOP and BIS, respectively. The suggested method was validated according to the International Conference of Harmonization (ICH) guidelines. The method was then successfully applied for the qualitative and quantitative determination of LOP or BIS as an example for gastrointestinal tract drugs in pure form and in their pharmaceutical dosage formulations. The proposed method is considered as a perfect alternative to traditional reported densitometric methods due to its simplicity, easy application, and inexpensiveness. No previously reported methods utilizing smartphones have been published for the determination of the studied drugs. The developed approach is considered the first TLC method using smartphones for the determination of some gastrointestinal tract drugs in their pure form and in pharmaceutical formulations.

A novel smartphone HPTLC assaying platform versus traditional densitometric method for simultaneous quantification of alfuzosin and solifenacin in their dosage forms as well as monitoring content uniformity and drug residues on the manufacturing equipment

“…2,33 Those reagents included iodine crystals, Dragendorff's reagent, ninhydrin, anisaldehyde and phosphotungstic acid. Although the literature reported the utilization of iodine crystals as a universal visualizing agent producing brown spots, 6,45 the intensity of the coloured spots was found to be highly variable, very sensitive to time and rapidly diminishing. Satisfactory and rapid results were obtained upon immersing the developed plate in Dragendorff's reagent for 30 seconds, with intense orange spots achieved for ALF and SOL.…”

“…The tremendous revolution in the built-in digital cameras of smartphones has opened new horizons for their applicability in different analytical techniques. 44,45 In this work, a HPTLC/ smartphone method was proposed, excluding any sophisticated instruments or arduous work, where the developed plates were captured by smartphone camera and rapidly processed to extract chromatographic results. To improve the method's accuracy and reproducibility, various key construction and shooting parameters were investigated and optimized as discussed below.…”

Image Analysis as a Tool for Understanding Quantitative Analysis in Chromatography

“…The conversion of spots to peaks and its analysis can be performed using commercially available (TLSee, AlfaTech, Italy; JustTLC, Sweday, Sweden) or freeware license (ImageJ, NIH, USA) software. ,− Recently, some new protocols have been presented. In these protocols, a smartphone with installed app (free of charge) has been used to get the TLC plate’s image and its analysis. ,− Eliminating the need for expensive equipment means that the cost of analysis drops drastically, allowing TLC experiments to be implemented in student exercises.…”

Smartphones app as portable colorimetric sensor for low-cost quantification of safranin dye in aqueous solutions

“…In the last years, digital image processing-based colorimetry (DIC or DIP-colorimetry) is wellknown and directly or indirectly applied as a novel, simple, portable, fast, low-cost, friendly, and effective analytical tool for the quantification of various chemical compounds such as dyes [15,16], metals [17,18], medicines [19,20], gases [21], and many other organic compounds [22][23][24]. In the last decade, colorful compounds have been effectively quantified in numerous samples due to applying the DIP-colorimetry method [23].…”