Abstract GP-74 IPC (2005). HPTLC of etoricoxib in tablets on silica gel with toluene - 1,4 dioxane - methanol 17:2:1. Quantitative determination by absorbance measurement at 235 nm. Linearity range was 500-1500 ng/spot. For stability studies the sample was subjected to acid and alkali hydrolysis, thermal, oxidaline and photo degradation. The peaks of all the degraded products were well resolved with significant different Rf values. The method was validated for different parameters and found suitable for routine quality control.

Indian J. Pharm. Sci. 67 (2), 182-186 (2005). HPTLC of atorvastatin calcium in its commercial single component tablet formulations (10 mg/tablet), on silica gel with benzene-methanol 7:3. The Rf value was 0.46. Quantitative determination by absorbance measurement at 281 nm. The method was validated in terms of linearity (200-600 ng/spot), precision (intraday variation: 0.25 - 1.01 %, interday variation: 0.21 - 0.88 %), accuracy and specificity. The LOD for atorvastatin calcium was 40 ng/spot, the LOQ was 200 ng/spot. The proposed method was successfully applied to determine atorvastatin calcium content of 10 individual tablet units of two market formulations after extracting atorvastatin calcium with methanol. All formulations were compliant with USP specifications (RSD less than or equal to 6 %) of the content uniformity test. The proposed HPTLC method can analyse ten or more formulation units simultaneously on a single plate and provides a faster and cost effective quality control tool for routine analysis of atorvastatin calcium formulation.

Chem. Pharm. Bull. 53, 691-693 (2005). HPTLC of trans-resveratrol in the roots of Polygonum cuspidatum and in dosage forms on silica gel with chloroform – ethyl acetate – formic acid 25:10:1. Quantitative determination by absorbance measurement at 313 nm. Linearity of determination of trans-resveratrol is between 0.5 and 3.0 µg with a correlation coefficient of 0.9989. LOD is 9 ng, and LOQ is 27 ng. The average percentage recovery is 99.9 - 100.7 %.

Anal. Sci. 22, 743-745 (2006). HPTLC of gatifloxacin and ornidazole on silica gel with n-butanol – methanol 8:1 and 1 drop ammonia with chamber saturation for 45 min. Quantitative determination by absorbance measurement at 302 nm. Linearity of determination of gatifloxacin is 100 – 500 ng and of ornidazole 250 – 1250 ng, with a correlation coefficient of more than 0.9850. The intra-day and inter-day coefficients of variation are found to be in the range of 0.68 - 2.58 % and 0.37 - 3.62%, respectively.

Pharmazie 61, 556-558 (2006). Preparative TLC of two benzofurans euparin, friedelin, and beta-sitosterol on silica gel with petroleum ether - ethyl acetate 20:1. Detection under UV light.

Indian Drugs 44 (3), 205-208 (2007). HPTLC of frusemide (= furosemide) and spironolactone on silica gel with toluene - acetonitrile - glacial acetic acid 70:30:2, with chamber saturation for 15 min at room temperature. Development over 8 cm, followed by air drying. Quantitative determination by densitometry at 254 nm. Linearity was between 8 - 32 ng/µL and 20 - 80 ng/µL for frusemide and spironolactone respectively. The method was validated for accuracy and precision. The limit of detection and quantification for frusemide was 3 ng/µL and 8 ng/µL respectively, and for spironolactone 2 ng/µL and 6 ng/µL, respectively. Recovery by standard addition was 99.4-101% for both compounds.

J. Chinese Trad. Patent Med. (Zhongchengyao), 27 (8), 900 - 903 (2005). TLC of Shajun Zhiyang lotion on silica gel with 1) benzene - ethyl acetate - isopropanol - methanol - ammonia 12:6:3:3:1; 2) benzene - ethyl acetate 30:1; 3) ethyl acetate. Detection 1) under UV 365 nm; 2) by spraying with 5% vanillin in H2SO4 solution and heating at 105 °C. Identification by fingerprint techniques. Quantification of matrine by HPLC.

Indian Drugs 44(10), 734 (2007). HPTLC of valdecoxib on silica gel with toluene - ethyl acetate 1:1. Quantitative evaluation by densitometry at 262 nm. Valdecoxib was well separated from rofecoxib. Linearity was between 800 and 1000 ng/zone. Recovery was 98.9 %.