J. Sep. Sci. 34, 2397-2404 (2011). HPTLC of 23 newly synthesized N-substituted 2-alkylidene-4-oxothiazolidines on RP-18 with 1) methanol - water, 2) acetonitrile - water, and 3) tetrahydrofurane - water. A quantitative structure-retention relationship study allowed to understand the chromatographic behavior of similar compounds.

J. Planar Chromatogr. 24, 491-496 (2011). HPTLC of pentose, hexose and disaccharides in pharmaceutical formulations on silica with aqueous micellar bile salt, sodium deoxycholate in acetonitrile 1:5 with chamber saturation. This mobile phase provided the best separation of the 22 phases tested. Detection by spraying with ethanolic orcinol solution.

J. Liq. Chromatogr. Relat. Technol. 32, 3049-3055 (2009). HPTLC of cinoxacin (1), pipemidic acid (2), ofloxacin (3), and pefloxacin (4) on silica gel with buffer solution (pH 5.5) - methanol 4:1 and acetonitrile - water - acetic acid, 3:20:2. Detection by dipping into various visualization agents. The detection limits for (1) to (4) were 0.1, 0.1, 0.5, and 0.75 µg/zone, respectively. Best detection conditions for (1) and (2) were obtained by dipping in Janus blue and immediate evaluation, and for (3) and (4) by dipping in Cresol red followed by heating at 120 ºC for 10 min for (3) and (4).

J. Planar Chromatogr. 24, 236-241 (2011). HPTLC of levodopa (LEV), carbidopa CAR), and entacapone (ENT) in a combined dosage form on RP-18 (prewashed with methanol) with acetonitrile - n-butanol - water - triethylamine 1:19:2:0.002, pH adjusted to 3.6 with phosphoric acid, in a twin-trough chamber saturated with mobile phase for 25 min. Quantitative determination by densitometry in absorbance mode at 282 nm. The hRf values were 46, 64, and 87 for LEV, CAR, and ENT, respectively. Linearity was between 300-1500 ng/zone for LEV, 200-1000 ng/zone for CAR, and 200-2000 ng/zone for ENT. The intra-day and inter-day precision was below 1.8 % RSD for all drugs. The recovery for LEV, CAR, and ENT (n = 3) was between 101.0 and 102.4 %.

J. Planar Chromatogr. 24, 121-124 (2011). HPTLC of kurarinone and sophoraflavanone G in the roots of Sophora flavescens on silica gel with chloroform - methanol 10:1 with chamber saturation for 30 min at 20 °C. Quantitative determination by absorbance measurement at 285 nm. The intra-day and inter-day %RSD were 1.9-2.0 % and 2.2-2.4 %, respectively. Instrument precision and repeatability of the method were 0.4-0.6 and 1.81-1.84 %, respectively. Average recovery was 96.3-103.4 % for kuraninone and 96.8-102.9 % for sophoraflavanone G. The limits of detection and quantification were 27 and 80 ng/band for kurarinone and 12 and 36 ng/band for sophoraflavanone G. Linearity was in the range of 200-1200 ng/band for kurarinone and 90-550 ng/band for sophoraflavanone. The hRf value was 31 and 50 for kurarinone and sophoraflavanone, respectively.

J. AOAC Int. 94, 1422-1426 (2011). HPTLC of eleutherosides B, E, and E1 in the fruits and leaves of E. senticosus and five other species of Eleutherococcus species after extraction with SPE, on silica gel in the horizontal chamber with saturation for 20 min, with a two-step development with 1) chloroform - methanol - water 70:30:4 and 2) chloroform - methanol - toluene - ammonium hydroxide 9:6:3:2. Detection by immersion in Liebermann-Burchard reagent for 1 s and heating at 110 °C for 10 min. The hRf values for the eleutherosides E, B, and E1 were 43, 53, and 66, respectively.

J. Planar Chromatogr. 24, 172-175 (2011). HPTLC of arjunolic acid on silica gel, prewashed with methanol, with chloroform - toluene - ethanol 4:4:1 in a twin-trough chamber saturated with mobile phase for 15 min. Detection by spraying with anisaldehyde reagent followed by heating at 110 °C for 5-7 min. Quantitative determination by densitometry at 600 nm. Linearity was between 50 and 500 ng/band. The hRf value was 28. The inter-day, intra-day, and inter-analyst precision was (%RSD, n = 6) 0.2-0.5, 0.3-0.4, 0.2-0.9 %, respectively. The recovery was in the range of 98.1-101.8 %. The robustness (%RSD, n = 3) was 0.2-2.1 %. LOD and LOQ were 18 and 50 ng/band, respectively.

J. Planar Chromatogr. 24, 520-523 (2011). HPTLC of streptomycin and amoxicillin, ampicillin, cefixime, cephalexin, cloxacillin, co-trimoxazole, doxycycline, erythromycin, gentamycin, metronidazole, tetracycline on titanium(IV) silicate coated plates with 0.5 M potassium bromide and ethanol 9:1 in a twin-trough chamber. Detection by spraying with a fresh 2 % solution of sodium carbonate and 5 % sodium nitroprusside dihydrate in 1 % acetaldehyde 1:1 or iodine solution (2 g iodine and 3 g potassium iodide in 100 mL water). Quantitative determination by densitometry in absorbance mode at 359 nm. The recovery was 97.9 %. LOD and LOQ were 2 and 12 ng/zone, respectively.