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 Chromatogr. A 1218 (19), 2668-2675 (2011). Use of the changes in emission of berberine cation, induced by non-covalent interactions with lipids on silica gel for detection and quantification of lipids using fluorescence densitometry in HPTLC/AMD. Three different HPTLC/AMD gradients were developed for the separation of 1) neutral lipid families and steryl glycosides, 2) different sphingolipids, and 3) sphingosine–sphinganine mixtures. Rationalization of fluorescent molar responses of studied lipids, and differences in response among different lipid families in the light of a previously proposed model of FDIC response, which is based on ion-induced dipole interactions between the fluorophore and the analyte, likewise, application of computational calculations using molecular mechanics as a complementary useful tool to explain high FDIC responses of cholesteryl and steryl-derivatives, and moderate responses of sphingolipids. Proposal of an explanation for the high FDIC response of cholesterol, whose limit of detection is 5 ng.

Acta Chromatographica 20(3), 463-473 (2008). TLC on silica gel with toluene – methanol – triethylamine 35:15:1. The hRf of atenolol and lercanidipine hydrochloride was 24 and 68, respectively. Detection and quantitative determination by absorbance measurement at 275 nm. The linearity was in the range of 2-12 µg/band for atenolol and 400–2400 ng/band for lercanidipine hydrochloride. The recovery was 98.9 % for atenolol and 99.7 % for lercanidipine hydrochloride.

2nd International Conference on New Development in Drug Discovery from Natural Product & Traditional Medicine PP82, 82 (2010). Eugenia jambolana pulp was dried in vacuum and enriched by chromatography on XAD 7HP ion-exchange resin, followed by Sephadex LH 20. HPTLC of both enriched extracts on silica gel with ethyl acetate – formic acid – acetic acid – water 100:11:11:26. Quantitative determination by absorbance measurement at 520 nm. The vaccum dried pulp and the enriched extracts 1 and 2 were found to contain 0.08 %, 17 % and 10 % of anthocyanins, respectively. Malvidin-3-laminariobioside was used as marker compound for quantitative analysis.

J. AOAC Int. 93, 754-764 (2010). The review describes analytical methods for drug substances, formulations, and clinical samples analyzed and validated by HPTLC during the period 1996-2009. Procedures, materials, and instrumentation for the different steps in the chromatographic procedure and validation of results are given; application to bulk drugs, formulations, stability studies, biological samples (e.g., urine and plasma), and hydrophobicity studies; and prospects for the future use of HPTLC for drug analysis are described. The sections cover the experimental procedures (sample preparation, stationary phases, mobile phases, application of standards and samples, chromatogram development, detection, documentation of chromatograms, densitometric quantitative analysis), determination of hydrophobicity, confirmation of zone identity, method validation, chiral separations, micropreparative layer chromatography, applications of HPTLC-densitometry, and future prospects for HPTLC in drug analysis. 155 references are reviewed.

J. Planar Chromatogr. 24, 105-107 (2011). TLC of twelve bisquaternary acetylcholinesterase reactivator HI-6-salts (sulfate, chloride, acetate, bromide, phosphate, mesylate, tartrate, iodide, malonate, salicylate, maleinate, and tosylate) on cellulose with acetone - acetic acid - water - toluene 5:2:2:1, butanol - acetic acid - water - toluene 1:1:1:1, isopropanol - acetic acid - water - toluene 5:2:2:1, and isopropanol - formic acid - water - toluene 6:2:2:1 in a twin-trough chamber. Detection under UV light at 254 nm and by spraying with Dragendorff’s reagent.

J. Planar Chromatogr. 24, 441-444 (2011). HPTLC of plant extracts and 17 polyphenolic compounds (apigenin, apigenin-7-glucoside, ellagic acid, hyperoside, isoquercitrin, kaempferol, kaempferol-3-glucoside, kaempferol-3-glucuronide, luteolin, luteolin-7-glucoside, methyl brevifolincarboxylate, myricetin, quercetin, quercetin-3-glucuronide, rutin, tiliroside, ellagic acid 3,3’-di-O-methyl ether 4-xylopyranoside) on silica gel (prewashed with methanol) with toluene - ethyl formate - formic acid 7:5:1 in an automatic developing chamber set with a twin-trough chamber at 22 °C and a relative humidity of 48 %. Detection under UV light at 254 and 366 nm, and at 366 nm after spraying with 1.0 % methanolic diphenylborinic acid 2-aminoethylester.

Acta Chromatographica 22 (4), 651-663 (2010). HPTLC of wedelolactone (WED) and asiaticoside (ASI) in Eclipta alba and Centella asiatica Linn., respectively, on silica gel with toluene - acetone - methanol - formic acid 60:40:40:1. The hRf value was 26 and 75 for ASI and WED, respectively. Detection by spraying with 10 % methanolic sulphuric acid. Quantitative evaluation by absorbance measurement at 317 nm for WED and at 530 nm after derivatization for ASI. The linearity was in the range of 50-250 ng/band for WED and 150-550 ng/band for ASI with r = 0.999 for WED and 0.9989 for ASI. The recovery of WED was 99.3 % and of ASI 99.5 %.