Chromatogr. Res. Int. 10, 1-11 (2014). HPTLC of artemisinin of Indian Artemisia annua L. was performed on HPTLC foil silica gel with n-hexane - ethyl acetate 3:1 in a twin-trough chamber up to a migration distance of 85 mm. Detection with anisaldehyde sulphuric acid reagent followed by heating at 110 °C for 10–15 min. Quantitative determination of artemisinin by densitometry at 540 nm. The hRf value of artemisinin (pink colored) was 28. The linearity was between 400 to 2800 ng/spot with a correlation coefficient of 0.9975. The precision (%RSD) was ≤3.3% (n=3). The LOD and LOQ were 40 ng/zone and 80 ng/zone, respectively. Recoveries were between 74 and 105 % for 0.6 mg/mL. Artemisinin content was highest in the leaf extract; no artemisinin was detected in the root extract.

Phytochemistry 105, 68-78 (2014). HPTLC bioautography of antifungal compounds in the roots of Morinda tormentosa on silica gel with petroleum ether - ethyl acetate 1:1, detection at UV 254 and UV 366 nm. The plates were incubated overnight at 37 ºC, after solidification of 20 mL of C. albicans suspension distributed over the plate. Bioautograms were sprayed with an aqueous solution of methyl thiazolyl tetrazolium chloride (2.5 mg/mL), followed by incubation at 37 ºC for 6h. Clear inhibition zones were observed against a purple background.

J. Chinese Modern Med. & Pharm. 20 (31), 54-56 (2013). Paracetamol and chlorphenamine maleate granule are an anti cold medicine effective for cold induced nasal congestion, headache, sore throat, fever, etc. Artificial bezoar is one of the main ingredients and bilirubin is the key effective component in the medicine. For quality control, TLC of the extracts and bilirubin on silica gel with isooctane – ethyl acetate – glacial acetic acid 11:5:3, detection under white light. Quantitative determination of bilirubin by UV spectrophotometry. Demonstration by applying to real life samples from three pharmaceutical factories indicated that the method was suited for the quality control of the medicine.

J. Planar Chromatogr. 28, 223-228 (2015). HPTLC of beta-amyrin in the leaves of five different Ficus species (F. carica, F. nitida, F. ingens, F. palmata and F. vasta) on silica gel with toluene - methanol 9:1. Detection with p-anisaldehyde reagent followed by heating. Quantitative determination by absorbance measurement at 550 nm. Precisions (intra- and inter-day) were 1.6-1.8 % and 1.7-1.8 % respectively (n=6). The hRF value was 58. Linearity was between 100 and 900 ng/zone. The LOD and LOQ were 32 ng and 96 ng/zone, respectively. Recoveries were 97.6-98.3 %.

Journal of Pharmacognosy and Phytochemistry 4 (2), 1-4 (2015). HPTLC of petroleum ether and ethanol extracts of aerial parts of Blumea lacera D.C. (Asteraceae), collected in the Gorakhpur district, with chloroform - benzene - formic acid 15:5:3. Evaluation in daylight revealed 11 zones, at least 9 of them at hRf between 3 and 47. The ethanol extract was purified by washing with water, chloroform and ethyl acetate successively, and then by fractionation on a silica gel (60-120 mesh) column; the benzene subfraction yielded, after exposure to iodine vapor, one yellow zone (hRf 41), identified (by IR, NMR and MS) as 3,5-dihydroxy-3’-methyl-6,7,4’-trimethoxyflavanone.

Phytochem. Anal. 26, 97-104 (2015). HPTLC of gymnemagenin in the leaves of Gymnema sylvestre on silica gel with toluene - chloroform - methanol 5:8:3. Detection by spraying with vanillin-sulfuric acid reagent, followed by heating at 110 °C for 10 min. Quantitative determination by absorbance measurement at 610 nm. The hRF value of gymnemagenin was 46. Linearity was in the range of 400-3000 ng/zone. LOD and LOQ were 0.07 and 0.55 ng/zone, respectively. Intra-day and inter-day precisions were below 2 % (n=3). Average recovery was 93 %.

J. Chromatogr. A, 1421, 184-202 (2015). An overview of instrumentation for HPTLC. As an instrumental technique, HPTLC has many advantages compared with high performance column chromatography (HPCC). For instance, HPTLC uses separate devices for each unit operation, usually at or close to atmospheric pressure, and affords higher flexibility supporting on-line or off-line operations, while HPCC requires a fully integrated instrument platform with high pressure capability. The unit operations of HPTLC are defined as sample application, development and evaluation with derivatization as an optional step, and several samples are separated simultaneously in general practice. The diversity of equipment for each operation contributes to the flexibility of HPTLC analysis and supports manual, semi-automated or full-automation of the separation process. Instrument platforms affect performance, repeatability, sample detectability, and time management of analysis. The current trend in HPTLC is to make the unit operations independent of the user. Review on current state-of-the-art in instrumental HPTLC for sample application, development, derivatization, photodocumentation, densitometric evaluation, and hyphenation with spectroscopic detectors with an emphasis on the variety and performance of commercially available systems. Some suggestions for best practices and avoidance of common mistakes are included.

J. Planar Chromatogr. 28, 386-390 (2015). HPTLC of gallic acid (1) and berberine (2) in a polyherbal formulation on silica gel with toulene – ethyl acetate – formic acid – methanol 24:18:8:1 for (1) and ethanol – water – formic acid 90:9:1 for (2). Quantitative determination by absorbance measurement at 273 and 366 nm for (1) and (2), respectively. The hRF values for (1) and (2) were 58 and 76, respectively.