J. Planar Chromatogr. 17, 238-240 (2004). HPTLC of aceclofenac and mosapride citrate (as internal standard) on silica gel in a twin-trough chamber equilibrated with the mobile phase with toluene - methanol - ethyl acetate - glacial acetic acid 550:250:200:1. Quantitative determination by densitometry at 284 nm.

leaves. J. Planar Chromatogr. 18, 244-248 (2005). Analytical and preparative TLC of coumarins from Peucedanum tauricum with bergapten, scopoletin, and coumarin A and B as standards on silica gel and on RP-2 with water - methanol 3:2 in horizontal chambers. Detection under UV light at 366 nm and densitometry at UV 366 and 320 nm. Re-chromatography with more selective mixtures of dichloromethane and acetonitrile 99:1 and 39:1. Identification by analytical co-chromatography with standards using mixtures of cyclohexane - ethyl acetate 3:1 and dichloromethane - acetonitrile 39:1.

J. Planar Chromatogr. 18, 203-206 (2005). TLC of primycin (a mixture of related compounds), streptomycin, dihydrostreptomycin on silica gel with A) n-butanol - water - methanol - acetic acid 4:2:1:1; and B) chloroform - methanol - water - 35% formic acid - n-butanol - formaldehyde 160:53:9:6:3:3. When using phase B repeated development improved the resolution. After development the plates were dried in a vacuum chamber at 100 °C. An efficient prewashing technique (with methanol - 35 % formic acid 1:1 followed by drying with hot air) made the TLC plates suitable for densitometric measurements at short wavelengths. Quantitative determination by absorbance measurement at 200 nm.

J. Pharm. Biomed. Anal. 39, 581-586 (2005). For post-production quality control of camptothecin derivatives irinotecan (CPT 11) and topotecan (TPT), HPLC and HPTLC methods have been developed which were suitable for identification, determination of purity and quantification. HPTLC on silica gel with methylene chloride - methanol - formic acid - water 82:24:2:1. After development, the plate was soaked in 15 % paraffin in n-heptane. Quantitative determination by fluorescence measurement at 366/>400 nm. The method was linear within the range of 100-1000 ng/mL for both CPT-11 and TPT. The method was validated for accuracy, precision, LOD, and LOQ.

J. AOAC Int. 88, 1530-1535 (2005). HPTLC of ciprofloxacin and degradation products (an ethylenediamine compound, a desfluoro compound, a by-compound, and fluoroquinolonic acid) on silica gel with chloroform - methanol - 25 % ammonia 43:43:14. Quantitative determination by densitometric analysis at 330 nm for fluoroquinolonic acid and at 277 nm for the other compounds. The method showed high sensitivity (limit of detection 10 to 44 ng), a wide linearity range (3 to 20 µg/mL), and good precision (2.32 to 6.46 % relative standard deviation) and accuracy (recovery rates 98.6 to 101.5 %) for individual constituents.

J. Planar Chromatogr. 18, 460-464 (2005). HPTLC of ethamsylate and mefenamic acid on silica gel prewashed with methanol, in a pre-saturated twin-trough chamber with chloroform - methanol - acetic acid 50:40:1. After drying at 50 °C for 5 min quantitative determination by absorbance measurement at 300 nm. The validated calibration range was 500-2500 ng/spot (r = 0.998) and 500-2500 ng/spot (r = 0.997) for ethamsylate and mefenamic acid, respectively.

J. AOAC Int. 88, 1562-1567 (2005). HPTLC of beta-asarone (cis-2,4,5-trimethoxy-1-propenylbenzene) and alpha-asarone in Calamus rhizome on caffeine-impregnated silica gel (prepared by immmersion of conventional silica gel plates into a solution of 80 g/L caffeine in dichloromethane for 1 s followed by drying at room temperature for 5 min, then heating at 80 °C for 5 min) with toluene - ethyl acetate 93:7. Quantitative determination by absorbance measurement at 313 nm. The method was validated in terms of stability of sample during chromatography, specificity for beta-asarone, linearity (25-300 ng, including samples containing 0.05-0.7 % beta-asarone), accuracy and precision. Recovery was 100.0-100.8 %, limit of detection 6.4 ng, and limit of quantitation 12.7 ng. The method allows proper identification of Calami rhizoma raw material, and the specific, accurate, and precise quantification of beta-asarone and alpha-asarone

J. Planar Chromatogr. 19, 187-190 (2006). Comparison of the iridoid composition of ten Stachys species by use of a TLC-densitometric method. TLC of harpagide, acetylharpagide, harpagoside, ajugoside, aucubin, and catalpol on silica gel with chloroform - methanol - water 25:10:1 and, occasionally, ethyl acetate - formic acid - water 9:2:1. Visualization of the spots by use of Ehrlich’s spray reagent (1 % dimethylaminobenzaldehyde in concentrated hydrochloric acid) followed by heating at 105 °C for 5 min. Quantitation by densitometry at 540 nm after 3 h.