J. Liq. Chrom. & Rel. Technol. 26, 2709-2717 (2003). HPTLC of betamethasone on silica gel with chloroform - methanol - water 36:10:1. Quantitation by densitometry at 245 nm. The method was tested for linearity, homogeneity, detection limit, accuracy, and working range. Mean recovery 99.2-100.1%. Selective, precise, and accurate procedure.

J. Pharm. Biomed. Anal. 36, 23-31 (2004). An HPTLC method is reported for stress degradation studies of guggulsterone in gum-resin exudates of comniphora mukul. The degradation was carried out under different ICH prescribed stress conditions, followed by development of a stability indicating HPTLC method. Separation on silica gel with toluene - acetone 9:1 after pre-washing with methanol. Quantitative determination by absorbance measurement at 250 nm. Guggulsterone E and Z showed Rf values of 0.38 and 0.46 respectively. The proposed method allows separation of the drug from its degradation products and hence is suitable for stability studies.

Br. using gymnestrogenin as reference. Indian J. Pharm. Sci. 66 (2), 242-244 (2004). HPTLC of gymnestrogenin in Gymnema sylvestre on silica gel with chloroform - methanol 9:1. Quantitative determination by absorbance measurement at 293 nm. Linearity was in the range of 4-10 µg. A gymnestrogenin content of 1.11 % was found in the test sample. Average percentage recovery was 99.1 ±0.27. The proposed method is precise and sensitive and can be used for detection, monitoring, and quantification of gymnestrogenin in Gymnema sylvestre.

56th IPC 2004, Abstract No. GP-46. Stability indicating HPTLC determination of cefuroxime axetil in bulk drug and in formulations on silica gel with chloroform - methanol 23:2. Quantitative determination by scanning at 278 nm. The sample was subjected to acidic, and alkali hydrolysis, oxidation and photo degradation. The degraded products were well separated. The method was validated for accuracy, precision, linearity, specificity, ruggedness, and recovery (98 - 100 %).

IPC 56th 2004, Abstract No. G-18. Curculigo Orchioides (Amary llidaceae) is used in various ayurvedic formulations. The rhizomes contain about 5.78 % total phenolis, gallic acid being the major component of the alcoholic extracts. HPTLC of gallic acid on silica gel with toluene - ethyl acetate - glacial acetic acid 25:15:1. The Rf valueof gallic acid was 0.19, the linearity range of 150-750 ng/spot. Rhizomes were found to contain 2.54 % gallic acid, formulations contained 5.13 % gallic acid, recovery was 99.5 %.

J. Planar Chromatogr. 18, 443-449 (2005). TLC of six 2-[1-(4-alkylpiperazinyl)]benzothiazoles, two 2-[4-(1-alkyl)piperidinyl]benzothiazoles, three 2-(N,N’-dimethyl-1,2-ethanediamino)benzothiazoles, and 2-[1-(4-aminopiperidinyl)]benzothiazole on RP-18 in a saturated horizontal chamber with mixtures of acetone and aqueous Tris (tris(hydroxymethyl)-aminomethane) buffer (pH 7.4). The organic modifier (acetone) content varied from 40 to 85 % in 5 % increments. Detection under UV.

J. AOAC Int. 88, 1530-1535 (2005). HPTLC of ciprofloxacin and degradation products (an ethylenediamine compound, a desfluoro compound, a by-compound, and fluoroquinolonic acid) on silica gel with chloroform - methanol - 25 % ammonia 43:43:14. Quantitative determination by densitometric analysis at 330 nm for fluoroquinolonic acid and at 277 nm for the other compounds. The method showed high sensitivity (limit of detection 10 to 44 ng), a wide linearity range (3 to 20 µg/mL), and good precision (2.32 to 6.46 % relative standard deviation) and accuracy (recovery rates 98.6 to 101.5 %) for individual constituents.

Abstract G-5, IPC (2005). HPTLC of telmisartan and hydrochlorothiazide on silica gel with chloroform - methanol - toluene 2:5:5 with chamber saturation for 30 min. Detection by spraying with ninhydrin reagent. Quantitative determination by absorbance measurement at 272 nm. The linearity was in the range of 250-500 ng/spot for telmisartan and 200-700 ng/spot for hydrochlorothiazide, recovery was 99-101 %. Accuracy, precision and linearity of the method were established.