J. AOAC Int. 90, 1203-1209 (2007). HPTLC of terpenelactones (total bilobalide, gingkolide A, and gingkolide B) on prewashed and sodium acetate preimpregnated silica gel with toluene - ethyl acetate - acetone - methanol 50:25:25:3 or ethyl acetate - hexane 9:1; also HPTLC of flavonol glycosides (quercetin, kaempferol, isorhamnetin as standards) on prewashed and preimpregnated silica gel with chloroform - acetone - formic acid - acetic acid 50:11:6:6. Plates were developed in solvent equilibrated, vapor saturated twin-trough chambers at 30°C. Densitometry in absorbance mode at 370 nm (for aglycones) and at 290 nm following a 1 s immersion in acetic anhydride and heating at different temperatures for varying lengths of time (for terpenelactones). Good relationship (95%) was determined between HPTLC and HPLC for determination of total flavonol glycosides. The HPTLC flavonol aglycone method also performed well in terms of accuracy and consecutive plate repeatability.

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.

Asian J. Chem. 20(6), 4940-4942 (2008). HPTLC of paracetamol and tramadol hydrochloride on silica gel with ethyl acetate - toluene - ammonia 60:40:1. Absorbance measurement at 254 nm. The method was linear in the range of 0.1-0.5 µg/mL and 0.9-4.5 µg/mL for tramadol and paracetamol respectively. The recovery was 98.4-99.9 % for both compounds. The method was suitable for routine analysis.

Abstract No. F-311, 61st IPC (2009). HPTLC of levocetirizine dihydrochloride and montelukast sodium on silica gel with chloroform - methanol 93:7. The hRf value was 21 and 65 for levocetrizine and montelukast, respectively. Quantitative determination by absorbance measurement at 345 nm. The method was linear in the range of 100-350 ng/band for levocetrizine and 600-1100 ng/band for montelukast.

Abstract No. F-18, 61st IPC (2009). HPTLC of levocetirizine dihydrochloride and montelukast sodium in bulk and tablet dosage formulation on silica gel with toluene - ethyl acetate - methanol - 25 % ammonia 5:14:5:2. Both drugs were well resolved with hRf values of 31 for levocetirizine and 44 for montelukast. Quantitative evaluation at 231 nm. The method was linear in the range of 500-2500 ng/band for levocetirizine and 1000-5000 ng/band for montelukast. Both drugs were also analysed by HPLC on RP18 column and results were comparable with HPTLC.

Analytical Chemistry - An Indian Journal 8(3) (2009) (without page number). A TLC method has been developed for determination of lacidipine in presence of its photodegradates. TLC on silica gel with toluene - acetone - methanol - 25 % ammonia 30:10:3:1. Densitometric evaluation at 284 nm. The chromatographic method was compared with a derivative spectrophotometric method and vierordt’s method and was found suitable for analysis of lacidipine in bulk drug as well as in dosage form.

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.