Abstract No. C-47, 61st IPC (2009). HPTLC of piperine and vasicine in polyherbal cough formulations on silica gel with dioxane - toluene - ethyl acetate - methanol - 25 % ammonia 15:20:10:10:3. Quantitative determination by absorbance measurement at 304 nm. The method was validated for accuracy, precision, LOD, LOQ, linearity and specificity and was found to be linear in the range of 2-10 µg/band for both vasicine and piperine.

J. Planar Chromatogr. 23, 70-74 (2010). Descripton of a selective and simple HPTLC method for quantification of oenothein B on the basis of the free gallic acid and total gallic acid content after acid hydrolysis. HPTLC of gallic acid on silica gel with benzene - methanol - acetic acid 90:16:8 in a glass chamber previously saturated with the mobile phase vapor for 20 min. Quantitative determination by absorbance measurement at 570 nm after derivatization with 1 % ethanolic iron(III) chloride solution. Average recovery of the active ingredient was in the range 95.4-104.6 %. Linearity was in the range of 440-2200 ng/band. The correlation coefficient r was 0.9991, LOD/LOQ were120/360 ng/band; repeatability (RSD) was 3.0 % and intermediate precision 1.0 %; intraday precision (RSD, n = 6, 440-2200 ng/band) was 3.8 to 5.2 % and interday precision 4.3 to 5.7 %. Both, precision and accuracy, were within acceptable limits for routine drug analysis (</= 15 %).

Encyclopedia of Chromatography Third Edition 1, 2319-2322 (2009). The author describes the techniques and instruments for the detection and quantification of radiolabeled substances in thin-layer radiochromatography (TLRC) or radio-TLC. In detail, film autoradiography, liquid scintillation counting (LSC), storage phosphor imaging and in situ radioactivity scanning are described. The instruments for these methods are highly automated providing significant advantages in radiopharmaceutical purity determination, metabolism studies and many other investigations.

International Journal of ChemTech Research 1(4), 1079-1086 (2009). TLC of wedelolactone, quercetin, and jatamansone in a polyherbal formulation. The formulation (oil) was extracted with methanol, the supernatant was concentrated under vacuum and used for chromatographic analysis. TLC on silica gel with toluene - acetone - formic acid 11:6:1 for wedelolactone, toluene - ethyl acetate - methanol 44:50:6 for quercetin and petroleum ether - acetone 3:1 for jatamansone. The hRf value of jatamansone was 34, of wedelolactone 56, and of quercetin 47. Densitometric evaluation at 254 nm, 285 nm and 366 nm for quercetin, jatamansone, and wedelolactone respecticely. The method was linear in the range of 500-2500 ng/band for wedelolactone, 3000-8000 ng/band for quercetin and 2000-6000 ng/band for jatamansone. The polyherbal oil formulation contained 1.62 %, 0.24 % and 0.11 % of wedelolactone, quercetin, and jatamansone respectively.

Indian Drugs 47(3), 55-56 (2010). An HPTLC method is described for estimation of n-valeric acid in Valeriana officinalis (Valerianaceae). Methanolic extracts of the plant were subjected to chromatographic analysis on silica gel with toluene - ethyl acetate 3:1. Densitometric evaluation at 254 nm. The method was linear in the range of 500-1500 ng/band with a recovery between 98.4-104.1 %. The plant extract was found to contain 1.13 % of n-valeric acid.

Scholars Research Library 2(1), 489-494 (2010). HPTLC of montelukast sodium and levocetirizine dihydrochloride on silica gel with toluene - chloroform - methanol - glacial acetic acid 6:20:10:1 in a twin trough chamber with chamber saturation for 25 min. The hRf value of levocetirizine was 64 and of montelukast 89. Densitometric evaluation at 302 nm. The method was linear in the range of 200-3200 ng/band for montelukast and 400-1200 ng/band for levocetirizine. The recovery was 99.9-100.0 %.

J. Planar Chromatogr. 23, 270-276 (2010). TLC of essential oils (obtained from different sage species by vapor destillation) on silica gel at -10 +/- 0.5 °C with toluene - ethyl acetate 19:1 in sandwich chamber saturated with mobile phase for 15 min. Quantitative absorbance measurement at 340 nm and 254 nm. After densitometry mass spectrometric analysis was performed using a TLC-MS Interface for direct elution of a given band from the plate.

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.