Abstract No. F-320, 62st IPC (2009). HPTLC of ezetimibe on silica gel with ethyl acetate - toluene - methanol - formic acid 10:10:1:1. Quantitative determination by absorbance measurement at 231 nm. The method was linear in the range of 301-3610 ng/band. Recovery was 99.3-100.4 % The drug was exposed to different stress conditions (acid, base, oxidative, thermal) and all degradation products were well resolved from the main compound.

J. Planar Chromatogr. 23, 18-22 (2010). TLC of amphotericin B on silica gel with chloroform - methanol - borate buffer (pH 8.3) 4:5:1 in a chamber pre-saturated for 20 min. Detection under UV 366 nm. The hRf of the main component was 46, and of the minor component 31. Quantitative determination by absorbance measurement at 385 nm. Direct bioautography with Candida albicans proved to be the most sensitive method, with a detection limit of 0.8 ng per spot. For densitometric evaluation of plates at 385 nm ten times more substance is required.

International Journal of ChemTech Research 2(1), 89-96 (2010). A micellar thin layer chromatographic method has been reported for identification of ketoprofen in drug formulation and spiked urine samples, followed by quantification of the drug by HPLC both in formulation and spiked urine samples. TLC on amino layer with a micellar mobile phase of 0.5 % aqueous solution of sodium dodecyl sulphate -Triton X100 - acetone 16:10:3. The drug was extracted from spiked urine samples with ethylene dichloride containing 10 % each of isomyl alcohol and diethyl ether, then the organic phase was evaporated and the residue was taken up in acetonitrile. Derivatization by exposure to iodine vapor and by spraying with Dragendorffs reagent. The hRf value of ketoprofen was 50.

J. Chromatogr. A 1218 (19), 2722-2731 (2011). Review on the features of TLC in the different areas of pharmaceutical analysis, like in-process and intermediate control, illustrated by impurity testing of active ingredients and final products, as well as its application in pharmaceutical research and development. Based on examples reported in the last five years it is shown that TLC is still a very popular and frequently used analytical method in the pharmaceutical industry, although there is a tendency in current pharmacopoeias for favouring HPLC.

J. of Chromatogr. Sci. 49, 129-135 (2011). TLC on silica gel with ethyl acetate – chloroform – formic acid – triethyl amine 70:30:1:1. Detection and quantification by densitometry. Good correlation between the integrated peak area of the studied drugs and their corresponding concentrations was found in different ranges.

J. Liq. Chromatogr. Relat. Technol. 34, 1850-1869 (2011). HPTLC of pipazethate (1) and its degradant 10H-pyrido[3,2-b][1,4] benzothiadiazine-10-carboxylic acid (2) on silica gel with chloroform - diethylamine - methanol 94:1:5. Quantitative determination by absorbance measurement at 225 nm. The hRf values of (1) and (2) were 35 and 28, respectively. Linearity was between 2-9 µg/zone for (1) and 1-6 µg/zone for (2). Limits of detection and quantification were found to be 53 and 180 ng/zone for (1), and 40 and 130 ng/zone for (2), respectively. Recoveries (by standard addition) were 100.1 % for (1) and 99.5 % for (2). Comparable results were obained with a validated HPLC method.

J. Planar Chromatogr. 25, 426-432 (2012). HPTLC of shanzhiside methyl ester (1) and barlerin (2) on silica gel with chloroform - methanol 4:1. Quantitative determination by absorbance measurement at 240 nm. The hRf of compounds (1) and (2) were 30 and 48, respectively. Linearity was in the range of 200-1000 ng/zone. Limits of detection and quantification were found to be 13 and 22 ng/zone for (1) and 18 and 31 ng/zone for (2), respectively. Recovery was found to be 99.2-99.5 % for (1) and 98.9-99.2 % for (2), respectively. The method showed comparable results to a validated HPLC method.

J. Planar Chromatogr. 26, 5-13 (2013). HPTLC of polystyrenes with molecular weight from 1920 to 520000 Da on silica gel with cyclohexane - tetrahydrofuran 39:11. The method allowed different ranges of molecular weight to be separated as a function of mobile phase composition using slight variations of cyclohexane and tetrahydrofuran. Comparison with other techniques for molecular weight distribution analysis is also discussed.