J. Food Comp. Anal. 21, 577-581 (2008). HPTLC of a novel fluorescent compound of nutmeg (Myristica fragrance) on silica gel with hexane – diethyl eter – acetic acid 50:50:1. Detection under UV at 265 nm or by spraying with sulphuric acid 50% followed by heating at 180 °C. The major fluorescent band at hRf 63 was further purified on silica gel using dioxane – acetonitrile – acetic acid 70:30:1. The hRf value of the novel compound was 61. Quantitative determination by absorbance measurement at 376 nm. Linearity was between 1 to 50 µg/spot. The compound was identified as 2-methyl-1,4,4a,8a-tetrahydro-endo-1,4-methanonaphthalene-5,8-dione.

Indian Drugs 45 (7), 536 - 541 (2008). Chyawanprash contains many phytoconstituents, out of which gallic acid, catechin, epicatechin are considered to be responsible for the antioxidant activity and piperine is responsible for the bioavailability enhancing effect. HPTLC with toluene - ethyl acetate - formic acid - ethanol 60:40:3:4. Quantitative determination by absorbance measurement at 254 nm. The hRf values of epicatechin, catechin, gallic acid, and piperine were 13, 32, 44, and 82 respectively. Recovery was 99.0 % for epicatechin, 96.1 % for catechin, 102.5 % for gallic acid and 100.6 % for piperine in Chyawanprash. The results obtained were compared with similar formulations available in the market employing tests for identification and purity determination. The developed method may be considered as an additional tool for quality control of Chyawanprash.

60th Indian Pharmaceutical Congress PA-203, (2008). HPTLC of paracetamol and nabumetone in combined tablet dosage form on silica gel with toluene - isopropyl alcohol - acetic acid 80:20:1. Quantitative determination by absorbance measurement at 236 nm. The method was linear in the range of 50-250 ng/spot for both compounds. The method was suitable for routine quality control of tablet dosage form.

Chromatographia 69 (1-2), 151-155 (2009). HPTLC of paracetamol and caffeine on RP18W with methanol - acetic acid - water 250:43:707. Quantification by absorbance measurement at 254 nm. The limit of detection and limit of quantitation for paracetamol was 100 and 191 ng/spot and 40 and 76 ng/spot for caffeine. Recovery was in the range of 99.6 - 106.8 % and the repeatability of the method was RSD < 1.9 %.

Anal. Chem. 76, 3251-3262 (2004). This review covers the literature of TLC/HPTLC found in Chemical Abstracts and ICI Web of Science from November 1, 2001 to November 1, 2003. Review Contents: 1. History, Student Experiments, Books, and Reviews; 2. Theory and Fundamental Studies; 3. Chromatographic Systems (Stationary and Mobile Phases); 4. Apparatus and Techniques; 5. Detection and Identification of Separated Zones; 6. Quantitative Analysis; 7. Preparative-Layer Chromatography and Thin-Layer Radiochromatography 8. Literature Cited.

Anal. Chem. 79, 5793-5808 (2007). HPTLC of phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidic acid, cardiolipin, sphingomyelin) on silica gel in a saturated chamber with chloroform-methanol - 2-propanol - triethylamine - 0.25 % potassium chloride solution 30:9:23:18:6. Detection by dipping in molybdenum blue reagent for 1 s and quantitative evaluation by densitometry. The sensitivity was in the range of 10 to 150 pmol/spot (depending on phospholipid acidity, hRf value, and ion polarity).

Anal. Chim. Acta 577 (1), 46-51 (2006). HPTLC of trigonelline in herbal extracts and in pharmaceutical dosage forms on silica gel with n-propanol - methanol - water 4:1:4. Quantitative determination by absorbance measurement at 269 nm. Linearity was between 100 - 1200 ng/spot (via peak area) and the correlation coefficient was 0.9991. The trigonelline content of herbal extracts quantified and estimated from the formulation was found to be well within limits (± 5 %) of the labeled content of the formulations. The method is reproducible and selective for the estimation of trigonelline by statistical analysis of the data.

J. Planar Chromatogr. 22, 115-119 (2009). HPTLC of metoprolol succinate and amlodipine besylate on silica gel (prewashed with methanol) with methanol - ethyl acetate - water - toluene - 25 % ammonia 15:50:3:30:3 in a twin trough chamber saturated for 20 min at 25 +/- 2 °C. Quantitative determination by absorbance measurement at 236 nm.