Phytochem. Anal. 19, 116-121 (2008). HPTLC of cinnamaldehyde (1) in the shoots of Cinnamomum zeylanicum, eugenol (2) in the flower buds of Eugenia caryophyllus and piperine (3) in the fruits of Piper nigrum on silica gel with petroleum ether - dichloromethane - formic acid 20:40:1. Quantitative determination by absorbance measurement at 290 nm. The hRf values were 47, 61, and 12 for (1), (2), and (3), respectively. Linearity was between 54 and 735 ng/spot for (1), 533 and 8531 ng/spot for (2), and 50 and 300 ng/spot for (3). The limits of detection and quantification were 12 and 21 ng/spot for (1), 240 and 426 ng/spot for (2), and 18 and 40 ng/spot for (3). Recovery was 99 % for each substance. No significant intra- and interday variation was observed. The method proved to be rapid and useful in comparison with GC and HPLC methods.

J. AOAC Int. 91, 13-20 (2008). Comprehensive proposal for the validation of qualitative HPTLC methods. The steps of the validation process (method selection and optimization, stability, specificity, precision, and robustness) are illustrated with examples of identification methods: green tea leaf, ginseng root, eleuthero root, echinacea root, black cohosh rhizome, licorice root, kava root, milk thistle aerial parts, feverfew aerial parts, and ginger root. The validation protocol is a key element for structuring, managing and documenting the validation process. HPTLC is suitable for reliable identification of botanicals because it can provide chromatographic fingerprints that can be visualized and stored as electronic images. Reproducibility is improved if suitable instrumentation is used, a standardized HPTLC methodology is implemented, and methods have been validated.

Chromatographia 69(3-4), 351-356 (2009). TLC of piroxicam and its degradation products on silica gel with ethyl acetate – toluene - butylamine 2:2:1. Quantification by absorbance measurement at 360 nm. It was found that piroxicam decomposes to produce pyridine-2-amine and 2-methyl-2,3-dihydro-4H-1?6,2-benzotiazin-1,1,4-trione, based on 1H NMR and LC–MS–MS qualification data.

60th Indian Pharmaceutical Congress PA-197, (2008) HPTLC of medroxyprogestrone acetate in bulk and injectable dosage form on silica gel with toluene - ethyl acetate - ammonia 800:200:1. Quantitative determination by absorbance measurement at 240 nm. The linearity was in the range of 50-1800 ng/spot. Recovery was 100.1 %. In the stability test (acid, base, peroxide, thermal, photodegradation) the compound was well separated from degradation products. The method was suitable for routine quality control and for monitoring stability.

60th Indian Pharmaceutical Congress PA-177, (2008). HPTLC of sibutramine hydrochloride on silica gel with benzene - methanol 9:1. Quantitative determination by absorbance measurement at 223 nm. The method was linear in the range of 2-22 µg/mL (UV-Visible) and 100-700 ng/spot (HPTLC). The recovery was 99.5-101.6 % for both methods. The proposed methods could be used for routine analysis of the drug in capsule dosage-form

J. AOAC Int. 91, 1387-1396 (2008). HPTLC on silica gel with chloroform - methanol 9:1 in the first direction for curcumin, demethoxycurcumin, bis(demethoxy)curcumin, and the synthetic dye metanil yellow, and with toluene - hexane - acetic acid 50:50:1 for sudan I and sudan IV in the second direction. Quantitative determination by absorbance measurement at 420 nm for curcumin and metanil yellow, at 491 nm for sudan I, and at 520 nm for sudan IV.

60th Indian Pharmaceutical Congress PA-202 (2008). HPTLC of 6-gingerol and 3-acetyl-11-keto-beta-boswellic acid on silica gel with n-hexane - ethyl actate 7:3 in a chamber saturated at ambient temperature. Quantitative determination by absorbance measurement at 254 nm. The hRf values were 48 and 58 for 3-acetyl-11-keto-beta-boswellic acid and 6-gingerol respectively. The recovery was 98.7-100.8 % for both compounds. The chromatographic conditions were suitable for routine analysis.

J. Liq. Chromatogr. Relat. Technol. 30, 2941-2951 (2007). TLC of 6-gingerol and 6-shogaol in commercial Ginger on silica gel with n-hexane - diethyl ether 2:3. Detection by spraying with anisaldehyde - sulfuric acid reagent. Evaluation under white light and quantitative determination by absorbance measurement at 577 nm.