Phytochem. Anal. 19, 236-243 (2008). HPTLC of curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3) in the rhizome of Curcuma longa L. on silica gel with toluene - acetic acid 4:1 for curcuminoid separation and n-hexane - ethyl acetate - acetic acid 16:5:1 for quantification of total curcuminoid content. Quantitative determination by absorbance measurement at 254 nm. To determine the free radical-scavenging activity of individual compunds, the plate was dipped into a 0.5 mM solution of 1,1-diphenyl-2-picrylhydrazyl (DPPH radical) in methanol for 5 s, dried in darkness at room temperature and heated at 60 °C for 30 s. Quantitative determination by absorbance measurement at 517 nm as negative peaks. The hRf values were 50, and 25 for (1) and (3), respectively. Linearity was between 80 and 250 ng/spot for (1), 40 and 280 ng/spot for (2), and 85 and 270 ng/spot for (3). The limits of detection and quantification were 20 and 60 ng/spot for (1), 10 and 30 ng/spot for (2), and 25 and 75 ng/spot for (3). Recoveries were 99.0 %, 96.9 %, and 95.8 %, (reference value 80 %), respectively. The intermediate/interday/intra-day precision for (1), (2), and (3) was 3.15 %, 3.00 %, and 2.85 %, (n=6), respectively. For the free radical-scavenging activity, linearity was between 70 and 400 ng for (1), 50 and 550 ng for (2), and 60 and 250 ng for (3). The limits of detection and quantification were 40 and 70 ng for (1), 25 and 50 ng for (2), and 45 and 60 ng for (3). The intermediate/interday/intra-day precision for (1), (2), and (3) was 6.50 %, 2.30 %, and 1.50 % (n=6), respectively.

Sci. Cult. 74 (1-2), 22-30 (2008). Bio-organic molecules such as oxygenated dibenzo-a-pyrones, their aminoacyl conjugates, and polyprenylbenzo-quinones have earlier been reported as transducers of energy in animals and human cells and were now found in four samples of meteorites. HPTLC on silica gel 60 with 1) n-butanol - acetone - acetic acid - water 7:7:2:4 for amino acids, followed by detection with ninhydrine reagent and densitometric evaluation at 610 nm; 2) n-butanol - acetic acid - water 3:1:2 for sugars, followed by detection with p-anisidine reagent and densitometric evaluation at 380 nm; and 3) chloroform - methanol 9:1 for dibenzopyrones, followed by densitometric evaluation at 240 nm and 360 nm.

60th Indian Pharmaceutical Congress PA-206, (2008). HPTLC of (-)hydroxy citric acid in fruits of Garcina Gummigutta on silica gel with n-propanol - water - acetic acid 50:50:1 in a twin-trough chamber saturated for 10 min. Quantitative determination by absorbance measurement at 210 nm. The method was linear in the range of 100-1000 ng/spot. Recovery was 99.8-100.9 %.

Ind. J. Pharm. Sci. 70(2), 233-236 (2008). HPTLC of duloxetine hydrochloride (in bulk drug and in tablet dosage form) on silica gel with chloroform - methanol 8:1. Quantitative determination by absorbance measurement at 235 nm. The method was linear in the range of 40-200 ng/spot. The method was suitable for routine quality control.

J. Pharm. Res. 6(4), 205-207 (2007). HPTLC of itraconazole on silica gel with toluene - acetone - triethylamine 30:30:1. Quantitative determination by absorbance measurement at 270 nm. The hRf value of itraconazole was 62. Linearity was between 200 and 600 ng. The percent drug estimated from the market formulation was found to be 99.6 and 100.2 by peak height and peak area respectively. The percent recovery of the drug (by standard addition method) was between 99.4 and 100.3.

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.

CBS 101, 12-13 (2008). During a drug substance stability study a mass imbalance was discovered in light degraded samples. HPTLC on silica gel first with ethyl acetate - heptane, then, after drying, with tetrahydrofuran in a horizontal developing chamber. Detection under UV 254 nm and by densitometry at 240 nm. During another project differences in color between batches of a drug substance were observed. HPTLC on amino phase with methanol in a horizontal developing chamber. Detection under white light and under UV 366/>400 nm.

Ind. J. Pharm. Sci. 70(2), 251-255 (2008). HPTLC of olanzapine and fluoxetine on silica gel with methanol - toluene 2:1. Quantitative determination by absorbance measurement at 233 nm. The method was linear in the range of 100-800 ng/spot for olanzapine and 1000-1200 ng/spot for fluoxetine. Recovery was 99.4-100.4 % for both compounds. Forced degradation studies (acid, base, oxidation, photolyses and thermal) revealed that all the degradation products were well resolved from the principal compound. The method was suitable for routine quality control.