J. Chromatogr. A 1217(8), 1395-1398 (2010). TLC of atenolol, propranolol and salbutamol and their enantiomers by using different modes of loading/impregnating the Cu(II) complexes of L-proline, L-phenylalanine, L-histidine, N,N-dimethyl-L-phenylalanine, and L-tryptophan on silica gel with 1) the Cu(II)-L-amino acid complex as chiral mobile phase additive, 2) ascending development of plain commercial plates in the solutions of Cu complex, and 3) using a solution of Cu(II)acetate as mobile phase additive for the commercial TLC plates impregnated by development with the amino acid solutions. Detection by exposure to iodine vapor. The detection limit was 0.18 µg for each enantiomer. For the best method performance the Cu(II)cation has to be involved.

J. Chromatogr. A 1218 (19), 2661-2667 (2011). Investigation of the performance of highly anisotropic nanostructured thin film ultrathin-layer chromatography (UTLC) media with porosity and architecture engineered using the glancing-angle deposition (GLAD) process. The anisotropic structures resemble nanoblades, producing channel-like features that partially decouple analyte migration from development direction, offering new separation behaviours. Study on GLAD-UTLC plate performance in terms of migration distance, plate number, retention factor and a figure of merit specific to GLAD-UTLC, track deviation angle, showing that migration distances increase with porosity by a factor of two for all feature orientations (up to a maximum of 22 mm) over the range of porosities considered in this study. Plate numbers approaching 1100 are observed for GLAD-UTLC plates when the nanoblade features are aligned with the development direction. The theoretical model describing mobile phase flow in anisotropic GLAD-UTLC media was in good agreement with experimental results. The plates provide channel features that reduce transverse spot broadening while providing the wide pores required for rapid migration and high separation performance, which may enable a greater number of parallel separations on miniaturized GLAD-UTLC plate formats. The small sizes should also make them compatible with the office chromatography concept in which office peripherals (inkjet printers and flatbed scanners) replace conventional TLC instruments.

62nd Indian Pharmaceutical Congress Abstract No. F-259 (2010). Health drinks usually contain several phytopharmaceuticals with immunomodulatory and antioxidant activities. TLC of gallic acid on silica gel with toluene – ethyl acetate – methanol – formic acid 15:15:1:4. The gallic acid content was established and the identity of the gallic acid zone in sample and standard was confirmed by UV spectra comparison.

J. Pharm. Sci. & Res. 2(2), 143-148 (2010). TLC of salbutamol sulphate (SS), bromhexine hydrochloride (BH), and etofylline (ET) in fixed dose formulation on hand-made silica gel plates with methanol – n-hexane 2:1. All three compounds were well separated with hRf values of 25 for SS, 71 for ET and 91 for BH. Detection at 254 nm as well as by exposure to iodine vapors. For spectophotometric quantification the bands of the selected drug in sample and standard mixture were scraped off, suspended in methanol, and the absorbance was measured at the maximum absorbance wavelength of each compound.

62nd Indian Pharmaceutical Congress Abstract No. F-249 (2010). TLC of risperidone and trihexyphenidyl hydrochloride on silica gel with methanol – chloroform – glacial acetic acid 160:40:0.1. Quantitative determination by absorbance measurement at 254 nm. The linearity was in the range of 20-60 µg/band and 10-30 µg/band for risperidone and trihexyphenidyl hydrochloride, respectively. The recovery was 99.4-99.9 % for both drugs.

Acta Chromatographica 20(4), 637-642 (2008). Specific separation of thiamine hydrochloride from riboflavin, nicotinic acid, calcium D-pantothenate, pyridoxine hydrochloride, cyanocobalamin, and ascorbic acid by TLC on silica gel with dioxane – water 1:1. Detection under UV light. Examination of the effect of impurities (metal cations and inorganic anions) on the chromatography of thiamine hydrochloride. The detection limit for thiamine hydrochloride was 0.09 µg/zone and the relative standard deviation of the hRf value of thiamine hydrochloride in five analyses was 14.9 %.

Acta Chromatographica 20(4), 709-719 (2008). HPTLC of trigonelline and 4-hydroxyisoleucine from Fenugreek seeds (Trigonella foenum-graceum) on silica gel with n–butanol – methanol – acetic acid – water 8:3:2:2. Detection by spraying with ninhydrin reagent. Quantification by densitometry at 266 nm for trigonelline, and at 395 nm for 4-hydroxyisoleucine. The linearity was in the range of 100-1000 ng/band for trigonelline and 50-500 ng/band for 4-hydroxyisoleucine, respectively, with r=0.9992 and 0.9986 respectively. The average recovery at three different levels was 99.4 % for trigonelline and 99.1 % for 4-hydroxyisoleucine.

Acta Chromatographica 21(3), 443-452 (2009). HPTLC on silica gel with ethyl acetate – hexane 3:17. Detection and quantification by densitometry at the maximum absorbance wavelength of 250 nm. The linearity was in the range of 60–260 ng/zone with r=0.9997. The limits of detection and quantification were 20 and 60 ng/zone, respectively. The precision and repeatability of the method were found to be 0.8 and 1.1 %, respectively. Recovery ranged from 97.9-100.1 %. The maximum zerumbone content in the rhizome was 1.81 %.