J. Planar Chromatogr. 15, 458-462 (2002). TLC of prenylamine, lidoflazine, bepridil hydrochloride, and fendiline hydrochloride on silica gel, alumina or florisil with several mobile phases comprising mixtures of n-hexane with polar modifiers such as dioxane, ethyl acetate, methanol, ethyl methyl ketone, tetrahydrofuran, and propan-2-ol. Plates were developed in horizontal chambers after conditioning for 15 min and visualized under UV 254 nm with a videoscanning system and by use of different detection reagents. The best separation was achieved on alumina with tetrahydrofuran - hexane 4:1.

J. Liq. Chrom. & Rel. Technol. 26, 2687-2696 (2003). Systematic investigation TLC of 9 phthalazines (e.g. 1-o-bromophenoxy-4-phenyl-phthalazine, 1-p-nitrophenoxy-4-phenyl-phthalazine, and 1-[3-(b-diethylaminoethyl)-4-methyl-7-coumarinyloxy]-4-phenyl-phthalazine and their corresponding 4-tolyl- and -4-benzyl-compounds) on silica gel with toluene - chloroform- methanol 70:20:1. The plates were developed twice with the same mobile phase at room temperature in a saturated N-chamber. Detection under UV 254 nm. The quality of HPTLC-FTIR spectra is sufficient for the identification of unknown substances.

CBS 81, 10-12 (1998). A number of applications of HPTLC in the bulk drug industry are presented: process optimization, fermentation process monitoring, impurity profile, vessel residue certification and bulk drug analysis. The technique is advantageous when a large number of similar samples is to be analyzed and time and cost considerations are of importance.

Part 2. J. Planar Chromatogr. 17, 40-45 (2004). Investigation of the quantitative structure-activity relationships (QSAR) between H1-histaminergic activity and chromatographic data for derivatives of 2-[2-(phenylamino)thiazol-4-yl]ethanamine, 2-(2-benzyl-4-thiazolyl)ethanamine, 2-(2-benzhydrylthiazol-4-yl)ethanamine, 2-(1-piperazinyl)benzothiazole, and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazole. TLC on silica gel, impregnated with solutions of amino acid analogs (propionic acid, propionamide, and n-amylamine) and their mixtures, with acetonitrile - methanol - buffer 2:2:1 and acetonitrile - methanol -dichloromethane - buffer 6:1:1:2. Detection under UV light at 254 nm.

J. AOAC Int. 87, 573- 578 (2004). TLC of propanolol/reagent azo adduct (with diazotized 4-amino-3,5-dinitrobenzoic acid) on silica gel with ethyl acetate - methanol 9:1, chloroform - methanol 4:1, methanol - ammonia 200:3 (plate was impregnated with 0.1 M methanolic KOH before spotting). Evaluation under UV light at 254 nm.

IPC 56th 2004, Abstract No. G-28. Neem Oil obtained from the seed kernels of Azardirachla indica (Meliaceae) is a fixed oil known as oil of Margosa. An HPTLC method is reported for the analysis of Neem oil as a bulk drug and formulations containing oil. TLC of neem oil extracted with chloroform, on silica gel with chloroform - n-hexane - methanol 18:2:1. Quantitative determination by scanning at 254 nm. The linearity range was 100 – 500 mg/mL. Formulations were found to contain 0.35 g/g of Neem Oil.

IPC 56th 2004, Abstract No. GP-26. HPTLC of triphala, an ayurvedic formulation containing about 3.60 % of total phenolics. Separation of alcoholic triphala extracts on silica gel with n-hexane - ethyl acetate 2:1. Rf value of the main spot gallic acid was 0.04 in triphala and its formulation. The method was found to be very specific for gallic acid having a linearity range of 0.2 - 1.6 mg/mL. Several formulations analyzed by HPTLC contained 5.2 - 7.6 % of gallic acid. The reported method is suitable for estimation of gallic acid in raw material and formulations.

Abstract G-28, IPC (2005). HPTLC of rosuvastatin on silica gel with chloroform - methanol - toluene 3:1:1. Quantitative determination by absorbance measurement. The hRf value of rosuvastatin was 53, recovery rate was between 98-102 %, LOD was 8 ng/spot and LOQ 26 ng/spot.