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.

J. Liq. Chromatogr. Relat. Technol. 31, 1925-1942 (2008). HPTLC of benzo[a]pyrene, benzo[b]fluoroanthene, benzo[k]fluoroanthene, benzo[ghi]perylene, fluoroanthene, 2-methylanthracene, and indeno[1,2,3-cd]pyrene on silica gel impregnated with caffeinesolution (by dipping in a solution of 2 g caffeine in 120 mL acetonitrile for 20 min, followed by drying for 15 min at 120 °C) with isopropyl acetate - acetonitrile 7:3 in a twin trough chamber at -20 °C. For fluorescence enhancement the plates were dipped in a solution of paraffin - n-hexane 1:1 and dried for 1 min in cold air. Quantitative determination by fluorescence measurement at 366/>400 nm. The method can be applied for control of the limit levels of the six polycyclic aromatoc hydrocarbons in water. The limits of quantitation were 0.08-0.44 ng/band depending on the substance. Linearity showed coefficients of correlation = 0.9920. The recoveries by stir bar sorptive extraction (n = 3) were between 87-100 % depending on the substance. The whole procedure was optimized to reach a sample throughput of 30 water samples, inclusive sample preparation by stir-bar sorptive extraction (SBSE), per 8-hour day.

Food Chem. 114, 1413-1420 (2009). HPTLC of methanolic fractions of stingless bee honey samples and commercial samples from Apis mellifera (European honey bee) on silica gel with a five step development with two different mobile phases: ethyl acetate - formic acid - acetic acid - water 100:11:11:27 and toluene - ethyl acetate - acetic acid 10:9:1. Detection by fluorescence measurement at 400 nm and absorbance measurement at 240 nm, after fluorescence induction at 365 nm with a mercury vapor lamp. Detection of flavonoids by spraying with an aqueous solution of 4 % aluminium sulphate. Flavonoids and coumarins were identified by comparison with commercial standards.

J. Planar Chromatogr. 22, 65-71 (2009). Presentation of two simple and rapid HPTLC methods for early detection of the effects of herbicides using two different groups of plant biomarkers, which were developed as field tests (Herbicide Weed Response test - HWR-Test). Phytochemical changes can be detected before any morphological changes are visible on the plants. These changes are defined as biomarkers and can be detected by HPTLC-screening. After overall identification of the phytochemical biomarker pattern, two different biomarker groups, carbohydrates and amino acids, were detected using modified reagents for color reactions. Evaluation under daylight and videodensitometric analysis of digital images by VideoScan software. The screening method was previously described [H. W. Ravn, M. Hjorth, L. Lauridsen, P. Kudsk, S. K. Mathiassen, L. Mondolot, Bull. Environ. Contam. Toxicol. 75, 236-245 (2005)].

Acta Chromatographica 21 (1), 83-93 (2009). HPTLC of quetiapine fumarate on silica gel with toluene - methanol 4:1. The hRf value of quetiapine fumarate was 37. Quantitative determination by absorbance measurement at 254 nm. There was no chromatographic interference from tablet excipients. The drug is susceptible to treatment with acid and alkaline hydrolysis, oxidation, and photodegradation. The method was able to separate the degradation products from the pure drug, it can be used for stability tests.