(Substanzidentifikation in der Dioden-Array Dünnschichtchromatographie). GIT Fachz. Lab. 658-660, (2003). HPTLC of codeine, tramadol, flupirtine and lidocaine on silica gel with ethyl acetate - methanol - NH3 17:2:1. Quantitation by densitometry between 198 and 610 nm. The UV spectra of the separated substances are used for the identification.

60th Indian Pharmaceutical Congress PA-211 (2008). HPTLC of triamcinalone acetonide on silica gel aluminum foil with toluene - ethyl acetate - ammonia 33:67:1 %.The hRf value of triamcinalone acetonide was 38. Quantitative determination by absorbance measurement at 240 nm. The method was linear in the range of 100-2000 ng/spot; recovery was 99.5 %. The stability indicating method has been successfully applied to forced degradation studies of triamcinalone acetonide (acid, alkali, hydrogen peroxide, photo degradation thermal and neutral hydrolysis) and resolved degradation products and excipients from triamcinalone acetonide.

J. AOAC Int. 92, 1373-1381 (2009). TLC of rabeprazole sodium and its degradation products on silica gel with isopropanol - 30 % ammonia 40:1 with chamber saturation. Quantitative determination by absorbance measurement at 284 nm.

60th Indian Pharmaceutical Congress PA-216 (2008). HPTLC of isomers of bupropion HCl on silica gel with quinine sulphate - methanol - water 13:20:12 (quinine sulphate served as a chiral selector). Evaluation under UV 366 nm. Linearity was in the range of 10-100 µg/spot for d(+)- and l(-)-isomers of bupropion. The isomer ratio was 80 % d(+)-bupropion and 20 % l(-)-bupropion.

J. Planar Chromatogr. 22, 355-358 (2009). TLC of atorvastatin calcium and fenofibrate on silica gel, prewashed with methanol, with toluene - methanol - triethylamine 35:15:1 in a twin trough chamber saturated for 25 min at room temperature and relative humidity of 60 +/- 5 %. Quantitative determination by absorbance measurement at 258 nm. The limit of detection and quantification for atorvastatin calcium was 25 and 77 ng/zone, respectively and for fenofibrate 292 and 886 ng/zone, respectively.

Abstract No. F-159 61st IPC (2009). HPTLC of telmisartan and amlodipine besylate on silica gel with tetrahydrofuran - dichloroethane - methanol - 25 % ammonia 30:10:5:2. Both compounds were well resolved with hRf values of 22 and 45 for telmisartan and amlodipine besylate respectively. Densitometric evaluation at 326 nm. The method was found to be linear in the range of 1200-7200 ng/band for telmisartan and 400-1400 ng/band for amlodipine besylate.

J. Liq. Chromatogr. Relat. Technol. 33, 179-190 (2010). TLC of salicylic acid and its derivatives, namely acetylsalicylic acid, salicylanilide, salicylaldehyde, salicylamide, salicylhydroxamic acid, methyl salicylate, phenyl salicylate, 3,5-dinitrosalicylic acid, 2,5-dihydroxysalicylic acid, 3-aminosalicylic acid, 4-aminosalicylic acid, and 5-aminosalicylic acid, on RP8, RP18 and HPTLC on RP18 and cyano phase with methanol - water; the content of methanol in mobile phase was gradually varied by 5 % from 20-100 %. Development in a chamber saturated for 15 min. Quantitative determination by scanning densitometry in absorption mode at the respective absorption maximum. The hRf values were recalculated on the RM values. The chromatograms were repeated in triplicate and mean hRf values were calculated. The results indicate that the chromatographic parameter of lipophilicity determined on RP8 and cyano phase may be used as a measure of lipophilicity of the investigated salicylic acid and its derivatives.

J. Serb. Chem. Soc. 74(6), 677-688 (2009). An NP-TLC method has been reported to study the lipophilicity of 5 ACE inhibitors (lisinopril, quinapril, fosinopril, enalapril, cilazapril and their metabolites). TLC on silica gel with several non-aqueous mono and binary solvent systems. Binary mobile phases demonstrated a decrease in hRf values of all 5 ACE inhibitors, i.e. increased retention with increased amounts of the less polar component in the mobile phase. Metabolites usually exhibited stronger retention, i.e. lower hRf values than the corresponding ACE inhibitor. This is probably due to a different interaction with silica gel because of two carboxylic groups in the structure of the metabolites, whereas ACE inhibitors contain only one carboxyclic group. Results obtained on NP-TLC were compared with those by RP-TLC and no significant difference was found regarding lipophilicity.