Asian Journal of Chemistry 22(8), 5951-5955 (2010). TLC on silica gel with cyclohexane - methanol - ethyl acetate - 25 % ammonia 10:3:6:1. The hRf value was 7 for atenolol and 69 for nifedipine. Densitometric evaluation at 230 nm. The linearity was in the range of 3-21 µg/band for atenolol and 1.2-8.4 µg/band for nefidipine. The recovery was 100.7 % for both drugs. The method was found suitable for analysis of the combined dosage form of atenolol and nefidipine without interference of excipients.

J. Planar Chromatogr. 23, 265-269 (2010). TLC of the epimers of cefaclor on silica gel (impregnated with beta-cyclodextrin by development with 1:9 aqueous beta-cyclodextrin solution - methanol) with chloroform - ethyl acetate - glacial acetic acid - water 4:4:4:1 with chamber saturation. Chromatograms were developed at 5 °C and dried at room temperature. Quantitative determination by absorbance measurement at 274 nm. The limit of detection was 0.24 and 0.27 µg/band for the epimers at hRf 26 and 33, respectively. The limit of quantification was 0.74 and 0.83 µg/band, respectively. The recovery was between 100.0 and 100.8 % and the precision between 0.7 and 1.7 %.

J. Planar Chromatogr. 23, 286-288 (2010). TLC of taxol with a stationary-phase gradient whereby parts of different TLC plates were connected by use of a MIGAS device. Separated taxol-containing zones were developed with methanol over 1 cm and thus moved to another plate. The lipophilic substance zone was cut out after separation of the sample on a silica gel plate with n-heptane - ethyl acetate 1:1. Further separation of taxol from accompanying hydrophilic substances was carried out on HPTLC RP-18W with methanol - water 4:1. The taxol-containing fraction was finally separated on silica gel with chloroform - acetone 3:1 in a horizontal chamber at constant temperature (30 +/- 1°C) and humidity (35 +/- 1 %). Detection under UV 254 and 366 nm. Quantitative determination by densitometry at 220 nm. The precision (n = 7) was 0.63 % and the repeatability (n = 7) 3.35 %. The limit of detection and quantification was 0.50 and 1.00 µg/zone, respectively; the correlation coefficient from linear regression was >0.98, and the linear calibration range was 1 - 10 µg/zone.

Talanta, 80 (5), 2007-2015 (2010). Presentation of a method for determination of oxybutynin hydrochloride (OX) in presence of its degradation product and additives in its pharmaceutical formulations. UV spectrophotometry using the first derivative of ratio spectra and measurment at 216 nm. Chemometric analysis using principal component regression and partial least-squares. HPTLC of OX and its degradation products methylparaben and propylparaben on silica gel with chloroform - methanol - ammonia - triethylamine 500:15:2.5:1. Quantitative determination by densitometry at 220 nm. Comparison of the results obtained with all three methods showed no significant differences.

62nd Indian Pharmaceutical Congress Abstract No. F-324 (2010). TLC of curcumin, piperine and quercetin in ayurvedic extract on silica gel with chloroform – toluene – ethyl acetate – methanol 4:4:1:1. The results obtained by the chromatographic method were comparable with a UV-VIS photometric method. All three compounds did not show any mutual interference.

Acta Chromatographica 21(4), 631-639 (2009). HPTLC on silica gel with toluene – ethyl acetate – formic acid 45:55:1. The hRf value was 31. Quantification by densitometry at 284 nm. The limit of quantification was 35 ng/band, recovery was 97.6-101.6 %, and precision 2.19 %RSD. The method was applicable for routine analysis and accelerated stability testing of terbinafine in pharmaceutical drug-delivery systems. It can be used as a stability-indicating method because it separated the drug from its degradation products.

62nd Indian Pharmaceutical Congress Abstract No. F-249 (2010). TLC of risperidone and trihexyphenidyl hydrochloride on silica gel with methanol – chloroform – glacial acetic acid 160:40:0.1. Quantitative determination by absorbance measurement at 254 nm. The linearity was in the range of 20-60 µg/band and 10-30 µg/band for risperidone and trihexyphenidyl hydrochloride, respectively. The recovery was 99.4-99.9 % for both drugs.

CBS 106, 2-4 (2011). TLC of milk samples on silica gel with dichloromethane - methanol - isopropanol - 25 % aqueous ammonia 3:3:5:2 in the horizontal DS chamber. Bioautography detection with Bacillus subtilis using the Chrom Biodip Antibiotic Kit and by dipping in a broth of Escherichia coli. Detection by spraying with an aqueous tetrazolium salt (MTT) solution of 0.2% and evaluation under daylight. With the E. coli assay the limit of detection for ciprofloxacin was 25 µg/kg, which is lower than with the Chrom Biodip test, while for enrofloxacin it was slightly higher (75 µg/kg).