IPC 56th 2004, Abstract No. GP-3. Simultaneous HPTLC determination of valdecoxib and tizanidine in tablets on silica gel with n-butyl acetate - formic acid - chloroform 7:3:2. Quantitative determination by densitometric scanning at 283 nm. The Rf values of valdecoxib and tizanidine were 0.78 and 0.39 respectively. Linearity range was 200 - 1000 ng/spot and 60 - 300 ng/spot respectively. Mean recovery for both of the compounds was 99.57 – 101.28 %. The method was validated for accuracy, precision, linearity, LOD, and LOQ.

J. Planar Chromatogr. 18, 181-187 (2005). Cameras and image-analysis techniques have been used for the evaluation of TLC and gel-electrophoresis for several years. A computer program has been developed to enable use of inexpensive image-generating systems such as CCD cameras, webcams, or flat-bed-scanners for the evaluation of TLC and electrophoresis separations in UV and white light. TLC of flavonoids and anthraquinone dyes on silica gel with water - formic acid - methyl ethyl ketone - ethyl acetate 1:1:3:5 and toluene - cyclohexane 2:1, respectively.

J. Planar Chromatogr. 18, 423-426 (2005). HPTLC of antibiotics (sulfadimidine, sulfadiazine, sulfaguanidine, trimethoprim) on silica gel without chamber saturation in a twin-trough chamber with chloroform - methanol 89:11. Quantification by videodensitometry at 254 nm. Limit of detection was 0.05 µg per spot for sulfadimidine, sulfadiazine, and sulfaguanidine, and 0.1 µg per spot for trimethoprim.

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.

J. AOAC Int. 88, 1549-1554 (2005). TLC of polymyxin B, framycetin, and dexamethasone on silica gel with methanol and methanol - n-butanol - 25 % ammonia - chloroform 14:4:9:12 for framycetin and polymyxin B. Quantitative determination by densitometry at 550 nm after detection with 0.3 % ninhydrin solution. Dexamethasone was separated with cyclohexane - ethyl acetate 2:3, quantitative determination by absorbance measurement at 245 nm. Similar accuracy, relative standard deviation values from 1.49 to 2.47 % and relative error values from 0.02 to 0.81 % are comparable to those obtained with the reference methods.

J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (3), 272-275 (2005). TLC of the extracts on silica gel with 1) n-hexane - chloroform - methanol 15:8:2; 2) n-hexane - ethyl acetate 9:1; 3) chloroform - benzene - glacial acetic acid 7:2:1. Detection 1) by exposing to iodine vapours; 2) under UV 365 and 254 nm. Identification by comparison with the standard. Quantification of usnic acid by densitometry at 290 nm. Validation by investigating the linearity range (0.50 - 2.50 µg/spot, r = 0.999), precision (RSD = 2.26 %, n= 5, within plate, and 2.97 %, n = 5, plate-to-plate), and standard addition recovery (97.5 %, RSD = 2.61, n = 5).

Abstract DP-15, IPC (2005). HPTLC of forskolin in herbal extract and opthalmic preparation (prepared from methanolic extracts of Coleus forskohlii roots) on silica gel with toluene - ethyl acetate 17:3. Quantitative determination by absorbance measurement at 292 nm. The method was found to be reproducible, accurate and precise.

III. Separation on various stationary phases. J. Liq. Chrom. & Rel. Technol. 27, 2613-2623 (2004). TLC of cholic, glycocholic, glycolithocholic, deoxycholic, chenodeoxycholic, glycodeoxycholic, and lithocholic acid on different preparations of silica gel and a mixture of silica gel and Kieselguhr with n-hexane - ethyl acetate - acetic acid in various volume compositions; successful separation was achieved with the compositions 4:4:1 and 22:21:5. Detection by 10 % aqueous sulfuric acid followed by heating at 120 °C for 20 min. Densitometric measurement at 250 nm.