Chromatographia 67 (5-6), 487-490 (2008). Simultaneous determination of escitalopram oxalate and clonazepam in a combined tablet dosage form by HPTLC on silica gel aluminum plates with toluene - ethyl acetate - triethylamine 14:7:6. Quantification by densitometry at 258 nm.

J. Pharm. Res. 6 (4), 233-235 (2007). HPTLC of ofloxacin and satranidazole on silica gel with n-butanol - ethanol 5:5 containing 4 % ammonia. Densitometric analysis at 320 nm. The hRf value of ofloxacin and satranidazole was 54 and 83 respectively. Linearity was between 200 and 1000 ng/spot for ofloxacin and between 300 and 1500 ng/spot for satranidazole. Recovery was 99.1 - 99.8 % for both compounds.

Isolation of the enantiomers. Chromatographia 68 (11-12), 1048-1051 (2008). TLC resolution of the enantiomers of the racemic drugs ketamine and lisinopril on silica gel with 1) ethyl acetate - methanol - water 3:1:1 and enantiomerically pure tartaric acid and (-)-mandelic acid as chiral impregnating reagents, for ketamine; and 2) acetonitrile - methanol - water - dichloromethane 14:2:2:1 with (+)-tartaric acid as the impregnating agent for lisinopril and using (+)-tartaric acid as mobile phase additive; and 3) acetonitrile - methanol - (+)-tartaric acid (0.5 % in water, pH 5) - acetic acid 70:10:11:7 which enabled successful resolution of the enantiomers of lisinopril. Investigation of the effects of temperature, pH, and the amount of chiral selector. Detection with iodine vapour. Isolation and identification of the separated enantiomers. The LOD was 0.25 and 0.27 µg for each enantiomer of ketamine with (+)-tartaric acid and (-)-mandelic acid, respectively, whereas 0.14 and 0.16 µg for each enantiomer of lisinopril with (+)-tartaric acid (both conditions) and (-)-mandelic acid, respectively.

Ind. J. Pharm. Sci. 69 (6) 841 - 844 (2007). HPTLC of artesunate on silica gel with toluene - ethyl acetate - acetic acid 20:80:2. Detection by treatment with vanillin reagent (1 % vanillin in 5 % ethanolic sulphuric acid) leads to pink zones which are stable for more than a day. Quantitative determination by absorbance measurement at 520 nm. The hRf value for artesunate was 44. Linearity was between 100 and 600 ng per spot. Recovery (by standard addition method) was 98.9 - 99.9 % for tablets and injections.

Chromatographia 68 (9-10), 855-859 (2008). HPTLC of moclobemide on silica gel with benzene – methanol – 40 % ammonia 70:30:1. Quantification by absorbance measurement at 238 nm. The degradation products reached under acidic, basic, and oxidising conditions were well resolved from the pure drug. Linearity was in the range of 50–600 ng/band, with a determination coefficient r2 of 0.9967 ± 0.51. LOD and LOQ, determined experimentally, were 10 and 30 ng/band, respectively. The method was used to investigate the kinetics of alkaline degradation, the Arrhenius plot was constructed and the activation energy calculated.

J. Liq. Chromatogr. Relat. Technol. 31, 1943-1958 (2008). TLC of salicylanilide on silica gel and silica gel mixed with Kieselguhr (with and without brilliant green as a detection reagent) with chloroform in a chamber saturated for 30 min. Detection without a reagent and by treatment with a 50 mg/100mL aqueous solution of brilliant green. Quantitative determination by absorbance measurement at 597, 305, and 268 nm. Proposition of a new index to evaluate objectively the visualizing effects of detected substances on thin layer using a densitometric method. The limit of detection, detection index, broadening index, modified contrast index, densitometric visualizing index, and linearity range were used to evaluate the visualizing effects of salicylanilide.

using HPLC, HPTLC and densitometry. Phytochem. Anal. 19, 550-559 (2008). HPTLC of the leaves of Lawsonia inermis L., on silica gel with ethyl acetate – formic acid – water 82:9:9 followed by drying at 110 °C for 15 min. Detection by spraying with diphenylborinic acid aminoethylester 0.5 % in ethyl acetate, followed by drying and dipping into macrogol reagent (1 g polyethylene glycol 400 in 20 mL dichloromethane). Quantitative determination by absorbance measurement at 337 nm. Chemical fingerprint was used for quality evaluation of herbal products and detection of adulteration. Comparison with an HPLC method gave comparable results.

Chem. 18(1), 667-672 (2006). HPTLC of mefenamic acid and drotaverine HCl in tablets on silica gel with methanol - toluene - triethylamine 10:75:2. Quantitative determination by absorbance measurement at 241 nm. The hRf values were 31 and 47 for mefenamic acid and drotaverine HCl, respectively. The method was validated in terms of accuracy, precision, specificity, ruggedness. Linearity was between 3800 and 8400 ng for mefenamic acid and 1200 and 2700 ng for drotaverine HCl. The recovery (by standard addition method) was in the range of 99.1-100.9 % for both compounds. The method could be used for routine analysis of these compounds and their combined dosage form.