59th Indian Pharmaceutical Congress F-55, 402, (2007). HPTLC of metformin hydrochloride on silica gel with methanol - chloroform - ammonium acetate 6:3:1. Densitometry at 236 nm. The method has a range from 100 - 300 ng/zone. The limit of detection and quantification was 25 ng and 100 ng/zone, respectively. The method was applied for analysis of metformin hydrochloride in multi-component formulations containing glipizide, gliclazide and glibenclamide as well as in serum.

Chromatographia 67 (3-4), 259-267 (2008). Investigation of saturated aqueous solutions of 28 different salts used as potential mobile phases for salting-out TLC, on silica gel, of a series of four mixed bis-aminocarboxylato cobalt(III) complexes. Confirmation of three alkali metal chlorides, and four alkaline earth metal chlorides, for linear dependences previously established on different adsorbents with (NH4)2SO4 solutions by linear regression analysis of chromatographic data obtained for fifteen mixed aminocarboxylato Co(III) complexes (four series) with solutions of ammonium chloride. Comparison of separation achieved with different salts. Li+, Mg2+, and Ca2+ chlorides are most suitable.

J. Planar Chromatogr. 21, 295-298 (2008). HPTLC of a test compound [1-(4-hydroxyphenylazo)-2-napthol] on RP-18 (prewashed with methanol) with acetonitrile - water - buffer (pH 4.8) in the desired volume ratio in a horizontal developing chamber saturated for 15 min. Quantitative determination by absorbance measurement with a diode array TLC scanner. The retention-composition relationship obtained with TLC is similar to those of pressurized planar electrochromatography and HPLC in the modifier concentration range 60-80 % but deviates substantially at higher modifier concentrations.

J. Pharm. Biomed. Anal. 47, 841-846 (2008). HPTLC of iridoid glycosides in the aerial part of Gambhari (Gmelina arborea) with iridoid gycoside 6-0-(2”, 3”- dibenzoyl)-o-L-rhamnopyranosylcatalpol as a chemical marker for the standardization of G. arborea plant extracts on silica gel with chloroform - methanol 4:1. Quantitative determination by absorbance measurement at 240 nm and at 430 nm after derivatization with vanillin - sulfuric acid reagent. The linear working range was between 1000-5000 ng/spot with a good correlation coefficient of 0.994.

IPA Convention, 2010, RA-PO 35. HPTLC of citicoline sodium in tablet formulation on silica gel with chloroform - methanol - water 3:7:3. The compound was well resolved with an hRf value of 53. Densitometric measurement at 280 nm. The method was linear in the range of 300-900 ng/band. HPLC analysis was performed on RP18 column using 1 % formic acid - methanol 19:1. Results obtained with either method were comparable.

E-Journal of Chemistry 7(2), 341-348 (2010). HPTLC of nebivolol hydrochloride and hydrochlorothiazide on silica gel with ethyl acetate - methanol - 25 % ammonia 17:2:1 with chamber saturation. The hRf value of hydrochlorothiazide was 21 and of nebivolol 41. Densitometric evaluation at 285 nm. The method was linear in the range of 200-1000 ng/band for nebivolol and 500-2500 ng/band for hydrochlorothiazide. The recovery was 98.9-102.4 %. Comparison of the HPTLC method with a RP-HPLC method and a UV spectroscopic method gave comparable results. The HPTLC method is suitable for routine quality control.

Quim. Nova. 34, 330-334 (2011). TLC of rosmarinic acid in preparations of Rosmarinus officinalis on silica gel with acetone – formic acid – methylene chloride 50:17:170. Detection under UV 366 nm. Quantitative determination by solid state differential pulse voltammetry (DPV). Linearity was between 0.694x10-3 to 0.526x10-3 mol/L. The limits of detection and quantification were 1.2x10-5 and 3.6x10-5 mol/L, respectively. The intermediate/interday/intraday precisions were 3.03 % and 2.2 %, respectively. Recovery (by standard addition) was 96.3 % for rosmarinic acid. The method presented high recovery levels compared to an HPLC method.

Journal of Environmental Science and Health, Part B 46, 557-568 (2011). Review on techniques and applications of TLC and HPTLC for separation, detection, qualitative and quantitative determination and preparative isolation of pesticides. Covered are sample preparation techniques, stationary phases, sample application, mobile phases, development methods using different chambers, detection under UV or by derivatization with various reagents, identification based on hRf values or by online HPTLC-MS, quantification by scanning densitometry or videodensitometry, preparative layer chromatography and thin-layer radiochromatography. Various applications are described. In the review period especially forensic analyses of human and animal samples for pesticides were numerous. The identification and quantification of components from plant extracts with pesticide activity is also reviewed and it is expected that this area will be especially active in the future given the large amount of ongoing worldwide research on phytochemical compounds.