Abstract No. F-235, 61st IPC (2009). HPTLC of olanzapine on silica gel with methanol - ethyl acetate 4:1. The hRf value was 35. Quantitative determination by absorbance measurement at 285 nm. The method was linear in the range of 100-600 ng/band. The method was suitable for analysis of formulations and in-house prepared mucoadhesive microemulsions.

60th Indian Pharmaceutical Congress PG-264 (2008). HPTLC of quercetin in acetone extracts of Psidium guajava leaves on silica gel with toluene - acetone - formic acid 38:10:5. Quantitative determination of quercetin by absorbance measurement at 364 nm. The correlation coefficient was 0.9847. There was a good correlation between peak area and corresponding concentration of quercetin. The proposed HPTLC method provided a good resolution of quercetin from other constituents present in acetone extract of tender leaves of Psidium guajava and can be used for the quantification of quercetin.

60th Indian Pharmaceutical Congress PA-223 (2008). HPTLC of curcumin, demethoxycurcumin and bis-demethoxycurcumin on silica gel with chloroform - methanol 19:1. The hRf values were 25, 38, and 61 for bis-demethoxycurcumin, demethoxycurcumin, and curcumin respectively. Quantitative determination by absorbance measurement at 420 nm. The method was linear in the range of 50-400 ng/spot (curcumin), 10-150 ng/spot (demethoxycurcumin), and 5-40 ng/spot (bis-demethoxycurcumin). Recovery was in the range of 99.2-100.5 % for all three compounds.

J. Planar Chromatogr. 22, 293-296 (2009). TLC of verbascoside, forsythoside B, caffeoyl-malic acid and plant (Ballota nigra, B. hirsuta, and B. rupestris) extracts on silica gel with formic acid - acetic acid - water - ethyl acetate 15:15:36:134. Quantitative determination by fluorescence measurement at 395 nm. It was observed that amounts of phenylpropanoids in Ballota nigra leaves increase during the main and secondary flowering periods in June.

J. Liq. Chromatogr. Relat. Technol. 31, 2673-2685 (2008). TLC of dehydroepiandrosterone on silica gel with chloroform - acetone 17:3 with chamber saturation for 30 min. Detection by dipping into 0.05 % aqueous solutions of visualizing agents (methylene violet, gentian violet, janus blue, methylene blue, malachite green, rhodamine B) and methanolic chloramine T/methanolic sulfuric acid solution. Quantitative determination by densitometry at 200 nm (before derivatization and for methylene violet), 657 nm (gentian violet), 487 nm (janus blue), 488 nm (malachite green), 580 nm (rhodamine B), and 361 nm (chloramine T). LOD was 0.29 µg/zone (without visualizing agent, with chloramine T and with rhodamine B), 4.19 µg/ zone with methylene violet, 1.10 µg/zone with gentian violet, 2.14 µg/zone with janus blue, and 4.19 µg/zone with malachite green, all with an application volume of 5 µL.

J. Planar Chromatogr. 23, 35-39 (2010). HPTLC of ß-carotene on silica gel (prewashed with methanol) with petroleum ether - hexane - acetone 2:3:1 in a saturated twin-trough chamber. Quantitative determination by absorbance measurement at 450 nm. Linearity was between 100 and 600 ng/band. LOD and LOQ were 0.11 and 0.37 ng/band, respectively. Average intra-day precision and inter-day-precision were 0.54 % and 0.50 %, respectively.

J. Planar Chromatogr. 23, 134-136 (2010). TLC of sertraline on silica gel (prewashed with methanol) with chloroform - ethyl acetate - triethylamine 25:15:1 in a twin-trough chamber previously saturated for 10 min at room temperature. Quantitative determination by absorbance measurement at 279 nm. The hRf for sertraline was 40. Intra-day precision and inter-day precision was 99.84 % RSD and 99.92 % RSD, respectively. A good linear relationship between response (peak area) and amount was obtained over the range 2.7-7.9 µg/band.

Densitometric analysis of flecainide in tablets. J. Planar Chromatogr. 23, 65-69 (2010). TLC of some antiarrhythmic compounds (disopyramide phosphate, verapamil hydrochloride, flecainide acetate, mexiletine hydrochloride, and tocainide hydrochloride) on RP8 and RP18 silica gel with organic-aqueous mobile phases containing citrate or acetate buffers at different pH in a horizontal chamber. The best separation of individual and mixed drug standards was achieved with tetrahydrofuran - citrate buffer (pH 4.45) 3:7. Flecainide acetate was identified and quantified by UV densitometry at 225 and 310 nm. Linear relationships were obtained between peak height or peak area and amount in the range 6.0 to 12.0 µg/spot, the correlation coefficient r was 0.990. Precision (RSD 1.1-5.9 %) and accuracy (96.2-103.6 %) were satisfactory.