J. Chromatogr. A 1218 (19), 2732-2736 (2011). A review on the sustainability and robust advantages of TLC and the parameters which are critical to the successful performance of product quality assessments in resource limited areas including field applications. The training required for successful performance of HPTLC assessments is much lower than that of other technologies with comparable reproducibility such as HPLC, because of the robustness and ease of use for HPTLC. Presentation of some of the successful applications of planar chromatography in resource limited countries. In practice in finished pharmaceutical products there are generally few active ingredients which are assessed making the HPTLC adequate for these analyses.

J. of Food Sci. & Biotechnol. 27(5), 129-133 (2008). TLC of gentamicin on silica gel with the lower phase of chloroform – methanol – 25 % ammonia 5:4:3 and after chamber saturation with the upper phase of the developing solvent. Detection by exposure to iodine vapor. Identification by comparison of the hRf values with the standards of the main components of gentamicin (Cl, C1 and C2). The results were compared with results obtained by HPLC and good agreement between both methods was found.

J. Liq. Chromatogr. Relat. Technol. 34, 864-887 (2011). Comparison of a one dimensional TLC-MS separation and fingerprinting method with a two-dimensional TLC-LC-MS method, when applied to the analysis of phenolic acids and flavonoids from Salvia lavandulifolia. TLC directly or indirectly coupled with mass spectrometric detection proved very useful in the analysis of the phenolic acid and flavonoid fraction selectively extracted from botanical material.

J. Planar Chromatogr. 25, 65-71 (2012). HPTLC of dapsone in presence of its oxidative degradants on silica gel with acetate - toluene 1:1. Quantitative determination by absorbance measurement at 289 nm. Linearity was in the range of 0.5-6.0 µg/zone. Recovery was 99.4 %. The method showed comparable results to a validated HPLC method.

J. Liq. Chromatogr. Relat. Technol. 36, 537-548 (2013). HPTLC of lamotrigine in tablets on silica gel with toluene - acetone - ammonia 6:14:1. Quantitative determination by absorbance measurement at 312 nm. The hRf value of lamotrigine was 55. LOD and LOQ were 0.57 and 1.73 µg/mL, respectively. Intermediate precision was below 1.9 %. Average recovery (by standard addition) was 101.5 %. Comparable results were obtained as compared with a validated HPLC method.

J. Planar Chromatogr. 27, 5-10 (2014). _x000D_HPTLC of magnolol (1) and konokiol (2) in the cortex of Magnoliae officinalis on silica gel with toluene - methanol 10:1. Detection by dipping into 2,2-diphenyl-1-picrylhydrazyl radical reagent (DPPH) in ethanol (1 g/L) for 40 min. Quantitative determination by absorbance measurement at 550 nm. Linearity was in the range of 160-960 ng/zone for (1) and 162-977 ng/zone for (2). The intermediate/interday/intra-day precisions were below 2 % (n=6). The LOD and LOQ were 40 and 149 ng for (1) and 32 and 85 ng for (2), respectively. Recovery was in the range of 94.5-105.9 % for (1) and 86.6-103.4 % for (2). The HPTLC-DPPH method showed comparable results to an HPLC method._x000D_

J. Planar Chromatogr. 28, 152-156 (2015). HPTLC of cholesterol from lung tissues on silica gel with petroleum ether - diethyl ether - acetic acid 90:10:1 in an unsaturated chamber. Detection by dipping in phosphomolybdic acid. Quantitative determination by absorbance measurement at 580 nm. Comparable results were obtained by HPLC analyses of the same samples.

CBS 118, 9-12 (2017). Comparison of TLC and HPTLC methods for (1) an aqueous-ethanolic extract of kidney vetch, (2) suppositories containing caraway extract, aqueously fermented root extracts of (3) barberry and (4) Solomon’s seal, and standards quinine hydrochloride, hyperoside, caffeic acid, rutin, fructose, caffeic acid, and noscapine hydrochloride. HPTLC on silica gel for (1) with chloroform – methanol – water 14:6:1, (2) with ethyl acetate – anhydrous formic acid – water 21:2:2, (3) with ethyl acetate – anhydrous formic acid – water 8:1:1 and (4) with chloroform – methanol – water 25:21:4. Detection by spraying with a (1) solution of 20 % antimony(III) chloride in chloroform and heating at 105 °C for 30 min, (2) 1 % methanolic solution of diphenylborinic acid 2-aminoethyl ester (natural products reagent), followed by a 5 % methanolic polyethylene glycol (macrogol) 400 solution and detection at UV 366 nm after 30 min, (3) bismuthate reagent (mixture of 0.85 g alkaline bismuth nitrate, 40 mL water, 10 mL acetic acid, and 20 mL potassium iodide solution (400 g/L), glacial acetic acid and water, 1:2:10), and (4) 1:1 mixture of 5 % sulfuric acid in ethanol and 2 % vanillin in ethanol and heating for 15 min at 105 °C. Compared to TLC, by HPTLC developing times were decreased, the separation power was higher and zones were sharper.