Analytical Methods 2, 521-531 (2010). An HPTLC method for determination for paliperidone in formulation as well as for in vitro release studies has been developed. HPTLC on silica gel with methanol - ethyl acetate 4:1. The hRf value was 54. Quantification was performed by densitometric evaluation at 254 nm. The method was linear in the range of 100-600 ng/band. The method was suitable for estimation of the drug in mucoadhesive microemulsion formulations, as well as for solubility and diffusion studies.

Asian Journal of Chemistry 23(1), 469-470 (2011). Several herbal formulations were analyzed for gallic acid contents. Tablets were powdered, subjected to hydrolysis by refluxing with 10 % HCl, filtrated and extracted with chloroform. Acidic aqueous extracts were concentrated and the residue was taken up in methanol. TLC on silica gel with ethyl acetate - formic acid 85:11. Gallic acid was observed at an hRf value of 89. Densitometric quantification of gallic acid at 272 nm. The method was linear in the range of 100-3000 ng/band. The method was suitable for analysis of formulations without interference from excipients. Gallic acid contents of different tablet samples varied from 0.06-0.15 % w/w.

Microbiol. Res.166, 87-98 (2011). Two-dimensional TLC of phospholipids from Legionella bozemanae on chloroform - methanol - water 14:6:1 in the first dimension and chloroform - methanol - glacial acetic acid 13:5:2 in the second dimension. Lipids were detected by spraying with concentrated sulfuric acid or by exposure to iodine vapor. The following phospholipids were identified: phosphatidylcholine, phosphatidyl-N,N-dimethylethanolamine, phosphatidylethanolamine, phosphatidyl-N-monomethylethanolamine, phosphatidylglycerol and diphosphatidylglycerol.

Analytical Chemistry - An Indian Journal 8(3) (2009) (without page number). A TLC method has been developed for determination of lacidipine in presence of its photodegradates. TLC on silica gel with toluene - acetone - methanol - 25 % ammonia 30:10:3:1. Densitometric evaluation at 284 nm. The chromatographic method was compared with a derivative spectrophotometric method and vierordt’s method and was found suitable for analysis of lacidipine in bulk drug as well as in dosage form.

Analytical Chemistry - An Indian Journal 9(2) (2010) (without page number). An HPTLC method has been reported for estimation of beta-sitosterol in whole plant powder of Tridax procumbens. HPTLC on silica gel with toluene - ethyl acetate - glacial acetic acid 40:10:1. Methanolic extracts of the plant material were used. For detection the plate was sprayed with anisaldehyde - sulfuric acid reagent. Densitometric quantification at 550 nm. The method was linear in the range of 10.0-70.0 µg/band. The plant material was found to contain 0.04 % of beta-sitosterol. The proposed method was suitable for routine quality control of plant as well as quantification of beta-sitosterol .

J. Sep. Sci. 33, 3794-3799 (2010). HPTLC of caffeine (1), theobromine (2) and theophylline (3) in different types of tea on silica gel with chloroform - dichloromethane - isopropanol 4:2:1. Quantitative determination by absorbance measurement at 254 nm. The hRF of (1), (2) and (3) was 65, 45 and 56, respectively. Limits of detection and quantification were 22 and 45 ng for (1), 23 and 46 ng for (2) and 22 and 43 ng for (3), respectively. The intra-day and inter-day precisions had a %RSD lower than 2.55 % (n=6) for all substances. Recoveries (by standard addition) were between 95.1-101.5 % for all the three methylxanthine derivatives. The values of LOD and LOQ obtained are similar with those obtained by HPLC.

J. Planar Chromatogr. 23, 265-269 (2010). TLC of the epimers of cefaclor on silica gel (impregnated with beta-cyclodextrin by development with 1:9 aqueous beta-cyclodextrin solution - methanol) with chloroform - ethyl acetate - glacial acetic acid - water 4:4:4:1 with chamber saturation. Chromatograms were developed at 5 °C and dried at room temperature. Quantitative determination by absorbance measurement at 274 nm. The limit of detection was 0.24 and 0.27 µg/band for the epimers at hRf 26 and 33, respectively. The limit of quantification was 0.74 and 0.83 µg/band, respectively. The recovery was between 100.0 and 100.8 % and the precision between 0.7 and 1.7 %.

Journal of Pharmacy Research 2(5), 789-791 (2009). TLC of harmaline in methanolic leaf extracts of Passiflora foetida on silica gel with chloroform - acetone - diethylamine 5:4:1. The hRf value of harmaline was 76. Densitometric quantification at 351 nm. The plant was found to contain 0.75 % w/w of harmaline. The method was linear in the range of 1-10 µg/band.