Trends Anal. Chem. 69, 114-122 (2015). The review discusses methods for the identification of bulk drugs and the active ingredients in formulations. The paper describes a general scheme for the profiling of related organic impurities in drugs involving the use of chromatographic techniques, including TLC.

Food Sci. Technol. Campinas. 35, 598-604 (2015). TLC of phosphatidylglycerol (1), phosphatidic acid (2), phosphatidylethanolamine (3), phosphatidylinositol (4), phosphatidylcholine (5) and lysophosphatidylcholine (6) in the seeds of flaxseed (Linum usitatissimum) on silica gel with chloroform - acetone - methanol - acetic acid - water 10:4:2:2:1. Detection by exposure to iodine vapours and evaluation in daylight. Solid phase extraction was performed to characterize the phospholipid composition during flaxseed development.

J. AOAC Int. 98, 1226-1233 (2015). HPTLC of three phosphodiesterase type 5 inhibitors, sildenafil (1), vardenafil (2), and tadalafil (3), and eight of their analogs, hydroxyacetildenafil (4), homosildenafil (5), thiohomosildenafil (6), acetildenafil (7), acetaminotadalafil (8), propoxyphenyl (9), hydroxyhomosildenafil (10), hydroxyhomosildenafil (11) and hydroxythiohomosildenafil (12) in finished products on silica gel with TBME - methanol - ammonia 28% 20:2:1. Detection under 254 and 366 nm UV light and by absorbance measurement at 232 nm. LOD was 30 ng/zone for all substances. Confirmation by HPTLC-ESI-MS. The method was successfully_x000D_ applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl, hydroxyhomosildenafil, or dimethylsildenafil).

J. Planar Chromatogr. 29, 239-246 (2016). HPTLC of ziprasidone and its 5 impurities on silica gel with toluene – methanol – glacial acetic acid 15:1:1. Qualitative analysis by absorbance measurement at 250 and 320 nm. The hRF values of ziprasidone and its impurities were 19, 11, 16, 7, 41 and 33, respectively. The retention behavior of ziprasidone and its five impurities was investigated by employing the experimental design and quantitative structure–retention relationship. See also J. Liq. Chromatogr. Relat. Technol. 39, 271-276 (2016).

Planta Medica 82(3), 238-243 (2016). Pure 6-gingerol was submitted to sulfation either with purified human sulfatases (SULT1A1, SULT1A2, SULT1A3, SULT1B1, SULT1C2, SULT1C3, SULT1C4, SULT1E1, SULT2A1, SULT2B1a, SULT2B1b, SULT4A1, and SULT6B1) or with cytosol of human organs (lung, liver, small intestine, kidney), in presence of [35S]-marked 3’-phosphoadenosine 5’-phosphosulfate, and, after centrifugation (13000 rpm, 3 min), the supernatant was analyzed by TLC on silica gel with acetic acid – n-butanol 2:1. The plate was dried with a hair-drier. Detection by autoradiography on an X‑ray film; the radioactive band corresponding to the [35S]-sulfated 6-gingerol (hRf 76) was cut out and eluted with 0.5 mL water into a glass vial for liquid scintillation counting. The strongest 6-gingerol-sulfating activity was exhibited, among the enzymes tested, by SULT1A1 (followed by SULT1C4, SULT1A3, SULT1E1, SULT1A2 and SULT1B1, the other sulfatases being inactive), and, among the organ cytosols, by the small intestine (followed by liver, lung and kidney). The same procedure was applied to detect, after spin filtration, the same [35S]-sulfated 6-gingerol produced from 6-glycerol and [35S]-sulfate in presence of plate-cultured human cells HepG2 (hepatoma) and Caco-2 (colon adenocarcinoma); the amount of the produced sulfated form clearly depended on the gingerol concentration.

CBS 113, 13-15 (2014). HPTLC of glycosylceramide Glc-d18:2 h16:0 from wheat germ and standards squalene, cholesteryl oleate, glyceryl trioleate, linoleic acid, ß-sitosterol, and ß-sitosterol glucoside on silica gel in the AMD 2 with a 18-step gradient modified from Opitz et al. (Chromatographia 73 (2011) 559), methanol replaced ethanol, and the mobile phase composition was changed slightly (pre-conditioning with 4 M acetic acid before each step, drying time 1.5 min, development duration 3 h and solvent consumption 200 mL). Detection by dipping in copper sulfate phosphoric acid reagent for 20 s and heating at 130 °C for 15 min revealed grey-brown bands. Densitometry evaluation by absorbance measurement at 546 nm. For Glc-d18:2 h16:0, regression analysis showed a polynomial relationship with coefficients of determination (R2) from 0.995 to 0.999 (n=3, 50 - 1000 ng/band). LOD (S/N 3) and LOQ (S/N 10) of Glc-d18:2_x000D_ h16:0 were 10 ng/band and 50 ng/band, respectively (n = 6).

J. Braz. Chem. Soc. 27, 1067-1077 (2016). HPTLC for the kinetic study involving the conversion of 2,3-dichloro-6,7-dinitroquinoxaline (1) into 2-chloro-6,7-dinitro-3-pyrrolidinoquinoxaline (2) and then into 6,7-dinitro-2,3-dipyrrolidinoquinoxaline (3) on silica gel through monosubstitution of a chlorine group with one equivalent of pyrrolidine. First, for obtaining calibration sets, 1 μL of solutions containing compounds (2) and (3) in chloroform with concentrations ranging from 1.0 to 8.0 mM were applied separately on chromatographic plates. In the kinetic study, 100 μL of a solution of compound (1) in chloroform (0.32 M) was added to 100 μL of pyrrolidine in chloroform (1 M eq). 10 μL of the reaction media taken at different times (30, 60, 90, 120, 180, 240, 300, 600, 1200 and 1800 s) was applied onto the TLC layer and separated with chloroform. All the final chromatograms were directly scanned to generate their digital image. Detection by absorbance measurement at 411 nm for (2) and 331 nm for (3). Kinetics profile was constructed for reagent (2) consumption and product (3) formation.

J. of China Pharm. 23 (8), 26-28 (2014). Compound Pipajiegeng ointment is a herbal TCM preparation for chronic cough, upper respiratory tract inflammation, and bronchitis. For quality control, TLC (1) of Eriobotrya japonica Thunb., on silica gel with chloroform – ethyl acetate – methanol – water 16:38:22:9, detection by spraying with 5 % phosphomolybdic acid in ethanol and heating at 105 °C until the zones are visible; (2) of Pericarpium Papaveris, on 2 % NaOH-containing silica gel with toluene – acetone – ethanol - ammonium hydroxide 20:19:3:1, detection by spraying with 5 % potassium iodobismuthate solution and viewing in daylight; (3) of Platycodon grandiflorus (Jacq.) A. DC., on 0.3 % NaOH-containing silica gel with cyclohexane – chloroform – methanol 15:11:1, detection by spraying with 25 % phosphomolybdic acid in ethanol and heating at 105 °C until the zones are visible; (4) of menthol, on silica gel with n-hexane – ethyl acetate 9:2, detection by spraying with 5 % vanillin in sulfuric acid – ethanol 4:1 and heating until the zones are visible. Quantification of morphine by HPLC.