Abstract G-35, IPC (2005). HPTLC of etoricoxib in tablets on silica gel with n-hexane - ethyl acetate 1:3. Quantitative determination by absorbance measurement at 237 nm. The method was linear within the range of 100-500 ng/spot with a recovery rate of 97.4 %. LOD was 40 ng/spot and LOQ 100 ng/spot.

Abstract CP-53, IPC (2005). HPTLC of andrographolide and wedelolactones in several market samples on silica gel with toluene - acetone - formic acid 9:6:1. Quantitative determination by absorbance measurement at 254 nm. The hRf value of andrographolide was 52 and of wedelolactone 58. Linearity was obtained between 200-400 ng/spot and 120-200 ng/spot respectively with recovery rates of 98.1-106.7 %. A complex coumarin from Eclipta alba was used as marker.

J. Planar Chromatogr. 18, 188-193 (2005). HPTLC of of bezafibrate and ciprofibrate in tablets and capsules on diol phases with hexane - tetrahydrofuran 4:1. Quantitative determination by absorbance measurement at 227 nm and videoscanning at 254 nm. Recovery measured by use of densitometry was 100.3 % (RSD 7.8 %) for bezafibrate and 98.0 % (RSD 6.1 %) for ciprofibrate. Videodensitometry resulted in recovery of 96.2 % (RSD 9.8 %) and 97.8 % (RSD 11.2 %), respectively.

J. Planar Chromatogr. 18, 207-211 (2005). HPTLC of rifampicin and isoniazid on silica gel (prewashed with methanol) in a horizontal chamber with ethyl acetate - methanol - acetone - acetic acid 5:2:2:1 after pre-saturation for 30 min. Densitometric evaluation by absorbance measurement at 345 nm for rifampicin and at 270 nm for isoniazid. For isoniazid and rifampicin CV was 0.42 and 0.16 %, relative standard error 0.01 and 0.13 %, and recovery 98.9 and 102.5 %, respectively.

J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (6), 740-742 (2005). TLC of liquorice and Albizia julibrissin Durazz flowers on silica gel with cyclo hexane - ethyl acetate - acetic acid 17:3:1. Detection by spraying with 5 % solution of vanillin - H2SO4 followed by heating until the spots are visualized. Identification by fingerprint technique.

TLC/HPTLC fingerprint profile. Indian Drugs 42 (7), 417-423 (2005). Unripe, powdered fruits of Mimusops elengi Linn. extracted individually and successively with acetone and methanol were evaluated for antimicrobial activity. HPTLC on silica gel with toluene - ethyl acetate - chloroform - acetic acid 35:35:28:2. Detection under UV 254 nm, 366 nm and after spraying with anisaldehyde sulphuric acid reagent for qualitative evaluation for different phyto constituents.

TrAC 25, 8 (2006). In the individual monographs of drug substances or finished products, only semi-quantitative TLC purity tests are mentioned and the number of TLC applications is steadily decreasing, being replaced by HPLC methods that are considered more appropriate. However, to comply with the latest and current pharmaceutical regulations, TLC manufacturers do not stop developing new equipment and accessories related to sample application, developing chambers, derivatization, documentation, and quantitative evaluation. Numerous examples of TLC/HPTLC applications in analytical research and quality control are mentioned to show the validity of this technique in the description of organic related impurities in drug substances and final products. Finally, authors ask analysts to present excellent, fully-validated and documented GMP/GLP-compliant TLC purity-test procedures to convince experts from pharmacopoeial committees and regulatory bodies of the importance of this analytical tool.

J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (8), 896-899 (2005). TLC of Wumei Rendan pills on silica gel with ethyl acetate - formic acid - water 2:1:1. Detection by spraying with 10 % ethanolic H2SO4 solution followed by heating at 105 ºC. Identification of the fingerprint. Quantification of menthol by GC, and of ammonium glycyrrhiziate by HPLC.