Anal. Chim. Acta, 572 (2), 237-242 (2006). Presentation of a stability-indicating method for simultaneous determination of the steroidal hormones levonorgestrel and ethinyloestradiol both in bulk drug and in low-dosage oral contraceptives by HPTLC on silica gel with hexane - chloroform - methanol 4:12:1. The hRf value of levonorgestrel was 65 and of ethinyloestradiol 43. The compounds were well separated from their degradation products. Quantitative determination by absorbance measurement at 225 nm. Linearity of levonorgestrel and ethinyloestradiol was 200–800 and 40–160 ng/spot, respectively.

Phytochem. Anal. 20, 154-158 (2009). TLC of the purgative constituents of rhubarb (sennoside A and sennoside B) on silica gel with 1-propanol - ethyl acetate - water - acetic acid 40:40:30:1. After drying detection by spraying with 10 % sulfuric acid and heating. For the eastern blotting assay the developed TLC plate was dried and sprayed with isopropanol - methanol - water 1:4:16. Transfer by using a PVDF membrane sheet for further treatment.

Chinese J. Modern Appl. Pharm. 25 (1), 66-69 (2008). TLC of Qufu Zhuanggu capsule extracts on silica gel with 1) n-hexane - ethyl acetate 4:1; 2) benzene - ethyl acetate 9:1; 3) chloroform - methanol 19:1; 4) cyclohexane - ethyl acetate 5:2; 5) n-hexane - acetone 3:1. Detection 1) under UV 365 nm; 2) by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the spot were visualized; 3) by treatment with ammonia vapors for 10 min; 4) by spraying with 20 % HClO4 in ethanol. Identification by comparison of the chromatograms with those of the standard psoralen.

Abstract No. 9192, IHCB (2009). HPTLC of betulinic acid in hydro alcoholic extracts of Nelumbo nucifera rhizome and seed, on silica gel with chloroform - methanol - formic acid 49:1:1. Detection by spraying with anisaldehyde reagent. Quantitative determination by absorbance measurement at 420 nm. The method was linear in the range of 2-10 ng/spot, recovery was 98.1-98.4 %.

J. Chromatogr. A 1216 (42), 7102-7107 (2009). HPTLC of co-trimoxazole tablets (combination of sulfamethoxazole and trimethoprim) on silica gel with toluene – ethyl acetate – methanol 100:57:43. Detection under UV 254 nm. The hRf values were 30 and 61 for trimethoprime and sulfamethoxazole, respectively. Quantification by densitometry at UV 254 nm. Cochran's criterion test indicated homoscedasticity of variances for the calibration data. The F-tests for lack-of-fit indicated that straight lines were adequate to describe the relationship between spot areas and concentrations for each compound. Repeatability and precision (%RSD) was 1.0 and 0.8 % for sulfamethoxazole as well as 1.3 % and 1.6 % for trimethoprim, respectively. Recovery was 99.0 % and 99.7 % for sulfamethoxazole and trimethoprim, respectively.

60th Indian Pharmaceutical Congress PA-230 (2008). HPTLC of amlodipine besylate (AB) and telmisartan (TMS) on silica gel with ethyl acetate - 1,4-dioxane - methanol - 25 % ammonia 30:3:6:3. The hRf value was 16 for TMS and 33 for AB. Quantitative determination by absorbance measurement at 323 nm. The method was linear in the range of 100-500 µg/mL (TMS) and 200-1000 µg/mL (AB), average recovery was 100.2-100.4 %.

Abstract No. 91334, IHCB (2009). Standardization of Tinospora cordifolia extract by HPTLC of syringic acid on silica gel with chloroform - methanol 8:1. The hRf value of syringic acid was 53. Quantitative determination by absorbance measurement at 254 nm.

Abstract No. F-272, 61st IPC (2009). HPTLC of wedelolactone on silica gel with toluene - ethyl acetate 9:1. Quantitative determination by fluorescence measurement at 366 nm. The method was linear in the range of 500-8000 ng/mL. Recovery was in the range of 100.2-101.0 %. The plant material was extracted using percolation, maceration, hot solvent extraction, supercritical fluid extraction, microwave assisted extraction, ultra sonication, and an orbital shaker. Quantification of wedelolactone in the extracts showed highest levels for Soxhlet extraction and lowest levels for supercritical fluid extraction.