Planta Med. 77, 548 (2011). HPTLC of forskolin and extracts from rhizomes of Coleus forskohlii on silica gel with toluene - methanol 12:1. The hRf value of forskolin was 27. Anisaldehyde-sulfuric acid reagent was used for spraying followed by heating of the plate at 105 °C for 5 min. Quantitative determination by densitometric scanning in absorbance mode at 545 nm.

J. Ethnopharmacol. 137, 341-344 (2011). HPTLC of quercetin (1) and kaempferol (2) in the leaves of Argyreia speciosa on silica gel with toluene - ethyl acetate 93:7. Quantitative determination by absorbance measurement at 254 nm. The hRf values of (1) and (2) were 32 and 75, respectively and their amount was found to be 0.6 % and 0.2 %, respectively.

J. Planar Chromatogr. 24, 242-247 (2011). HPTLC of E-guggulsterone (EG), Z-guggulsterone (ZG), 11-keto-ß-boswellic acid (11-KBA), and 3-acetyl-11-keto-ß-boswellic acid (A-11-KBA) in pharmaceutical formulation on silica gel with n-hexane - chloroform - ethyl acetate - methanol 10:3:3:1 in a twin-trough chamber with saturation for 15 min at room temperature (25 +/- 2 °C) and relative humidity of 60 +/- 5 %. Quantitative determination by densitometry in absorbance mode at 254 nm. The hRf values were 28, 39, 61, 68 for 11-KBA, A-11-KBA, EG, and ZG, respectively. The linearity range was 10-90 ng/band for EG and ZG, and 50-450 ng/band for 11-KBA and A-11-KBA. The repeatability of measurement of peak area and of sample application (%RSD) were 1.1 and 1.3 % for EG, 1.4 and 1.5 % for ZG, 0.5 and 1.1 % for 11-KBA, and 1.1 and 1.1 % for A-11-KBA, respectively. The mean intra-day and inter-day precsions (%RSD) were 1.0 and 1.1 % for EG, 1.1 and 0.9 % for ZG, 0.7 and 0.8 % for 11-KBA, and 1.1 and 1.3 for A-11-KBA. The method precisions (%RSD) were 1.3, 1.3, 1.1, and 1.3 % and the recoveries (by standard addition) were 96.9, 97.4, 97.6 and 97.2 % for EG, ZG, 11-KBA and A-11-KBA, respectively.

J. of Chromatogr. A 1248, 169-177 (2012). Purified oligomers of hyalobiuronic acid are indispensable tools to elucidate the physiological and pathophysiological role of hyaluronan degradation by various hyaluronidase isoenzymes. Establishment and validation of a novel sensitive, convenient, rapid, and cost-effective HPTLC method for the qualitative and quantitative analysis of small saturated hyaluronan oligosaccharides consisting of 2–4 hyalobiuronic acid moieties. HPTLC on amino phase with 1-butanol - formic acid - water 3:5:2 or 3:4:1. Detection 1) by spraying with orcinol in various concentrations of sulfuric acid; 2) by dipping into the reagent of orcinol in 10 % sulfuric acid and Morgan–Elson reagent; 3) by illuminating with white light and UV 366 nm after heating. The simple reagent-free in situ derivatization of 3) resulted in a detection limit of 7–19 pmol/band and LOQ of 37–71 pmol/band depending on the analyzed saturated oligosaccharide. Identification of the analytes by TLC-ESI-MS. The validated HPTLC method, as an alternative to sequential techniques such as HPLC and CE, can easily be automated and is applicable to the analysis of multiple samples in parallel.

CBS 107, 5-7 (2011). HPTLC of coenzyme Q10 in toluene extracts of soft gel capsules on silica gel (pre-washed by development from both sides with methanol) with toluene in the horizontal developing chamber from both sides. Detection under UV 254 nm. The hRf value of coenzyme Q10 is 20. Quantitative absorption measurement at 282 nm, evaluation via peak height. Linearity was in the range of 20-50 ng/band. Polynomial calibration ranged 20-150 ng/band. The parallel analysis of 60 samples (10 samples each from 6 batches) and 12 standards required only 86 min. The test for content uniformity was performed with 10 samples according to the European Pharmacopoeia and the USP 34 and the requirements were met.

CBS 109, 13-15 (2012). HPTLC-AMD of tolyltriazoles and by-products after ozone treatment of water samples, on LiChrospher silica gel (pre-washed with 2-propanol and dried at 120 °C for 30 min) by automated multiple development (AMD) using a 22-step gradient from methanol - formic acid 200:1 over dichloromethane to n-hexane. Detection under UV 254 nm and by spraying with 2,4-dinitrophenylhydrazine reagent, evaluation under white light. Densitometric measurement at 190, 200, 220, 240, 260, 280, and 300 nm before derivatization and at 380, 400, and 420 nm after derivatization. Coupling of HPTLC with HPLC-QTOF/MS using the TLC-MS Interface offline with water - acetonitrile 1:1 with 5 mmol ammonium acetate as extraction solvent and a flow rate of 0.2 mL/min.

J. Planar Chromatogr. 27, 181-185 (2014). HPTLC of plumbagin in the root of Plumbago zeylanica on silica gel with n-butanol - chloroform - petroleum 2:3:1. Quantitative determination by absorbance measurement at 268 nm. The hRF value for plumbagin was 58. Linearity was in the range of 225-675 ng/zone. The intermediate/interday/intra-day precision were below 2 % (n=3). The LOD and LOQ were 30 and 90 ng/zone, respectively.

J. Planar Chromatogr. 27, 47-51 (2014). HPTLC of clotrimazole in vaginal tablets on silica gel with toluene - acetone 3:2. Quantitative determination by absorbance measurement at 215 nm. The hRF value for clotrimazole was 27. Linearity was in the range of 1000-2400 ng/zone. The intermediate/interday/intra-day precisions were below 1.3 % (n=6). Recovery was between 99.1 and 100.1 %.