J. Planar Chromatogr. 24, 77-81 (2011). HPTLC of belleric acid on silica gel, prewashed with methanol, with toluene - ethyl acetate - methanol - formic acid 15:15:7:1 in a saturated chamber at 22 °C and 65 % relative humidity. Quantitative determination by absorbance measurement at 205 nm. Average recovery was 98.7-100.9 %. Linearity was between 250 and 1250 ng/zone. Repeatability and intermediate precision (%RSD) were 1.2 and 1.5 %, respectively. LOD and LOQ were 49 and 148 ng/zone, respectively. The hRf value of belleric acid was 35.

J. Planar Chromatogr. 24, 337-343 (2011). TLC of tenoxicam and pyridine-2-amine on silica gel with ethyl acetate - toluene - butylamine 2:2:1 with chamber saturation for 15 min at room temperature. Quantitative determination by absorbance measurement at 288 nm. The hRf value was 52 and 64 for tenoxicam and pyridine-2-amine, respectively. Linearity was between 35-1820 mg/mL for tenoxicam and 10-500 mg/mL for pyridine-2-amine. LOD and LOQ were 0.9 and 2.6 mg/band for tenoxicam and 0.1 and 0.3 mg/band for pyridine-2-amine. The recovery was 99.0-99.9 % for tenoxicam and pyridine-2-amine. The %RSD did not exceed 1 % at any level.

Chromatographia 75 (9-10), 449-456 (2012). Proposal of application of OPLC and TLC techniques with micellar mobile phases to evaluate the lipophilicity of 21 newly synthesized 1,2,4-triazoles, compounds of potential importance in medicine or agriculture as fungicides. The separation of the compounds 1) by micellar TLC on cyano phase with buffered SDS – tetrahydrofuran 4:1 in a sandwich chamber; 2) by micellar OPLC on cyano phase with buffered SDS - tetrahydrofuran 4:1 in off-line mode; 3) by reversed-phase TLC on RP-8 phase with buffered solutions of acetonitrile and tetrahydrofuran in concentrations varied in the range of volume fraction from 0.3 to 0.7, in constant steps of 0.1. Detection by densitometric scanning at UV 200 nm, or by means of a video camera at UV 254 nm. Application also of micellar HPLC technique on RP-8 column eluted with buffered SDS - acetonitrile 4:1, whereas in OPLC and TLC, cyano phases were applied, which allowed the use of micellar effluents in planar chromatography measurements. Determination of the micellar parameters log km and comparison with extrapolated R M0 values determined from reversed-phase TLC experimental data, as well as with log P values (Alog Ps, AClog P, Alog P, Mlog P, KowWin, xlog P2 and xlog P3) calculated from molecular structures of solutes tested. Application of principal component analysis (PCA) and linear regression showed the results of considerable similarity between partition and retention parameters as alternative lipophilicity descriptors, and indicated micellar chromatography as a suitable technique to study lipophilic properties of organic substances.

J. Liq. Chromatogr. Relat. Technol. 35, 2548-2564 (2012). HPTLC of tocopherol acetate in pharmaceutical preparation on silica gel with chloroform - cyclohexane 11:9. Quantitative determination by absorbance measurement at 272 nm. The hRf values for tocopherol acetate and its related substance were 47 and 38, respectively. Limits of detection and quantification were 50 and 150 ng/zone, respectively. The intermediate/inter-day/intra-day precision was below 1.4 % (n=3). Recovery was between 99.8 and 101.5 %, respectively. A better separation of tocopherol acetate was obtained using NP-TLC technique than by RP-TLC technique.

Chinese J. of Veterinary Drugs 46 (5), 29-31 (2012). TCM is more and more important in veterinary medicine. It has been found that some medicines were illegally mixed with certain chemicals harmful to the animal body. Rapid screening of the additives illegally mixed in Astragalus polysaccharides injection by TLC on silica gel with 1) chloroform – methanol – acetone – ammonia 9:2:1:0.05 and 2) ethyl acetate – ethanol 1:1. Detection 1) under UV 254 nm; 2) by spraying with 5 % potassium iodobismuthate solution and evaluation in daylight; 3) by exposure to iodine vapor for a few minutes and evaluation under UV 254 nm. Identification of lincomycin, enrofloxacin, novalgin, 4-acetamino phenol, moroxydine hydrochloride, and ribavirin by comparison of the fingerprint with individual standards, with detection limits of 2.0, 0.5, 1.0, 0.5, 1.0, and 4.0 mg/mL, respectively. The method was applied to 25 batches of market samples and the results were compatible with those obtained by HPLC.

Ethnomed. Ethnopharm. (1), 53-54 (2012). Cissus hexangularis Thorel ex Planch is a TCM herb. Its dried rattan is effective in relieving rheumatic pains and invigorating the circulation of blood, and is often used in drug preparations against rheumatism, pain or numbness, lumbar muscle degeneration and traumatic injury. TLC of the extracts and standards resveratrol and bergeninum on silica gel with chloroform – ethyl acetate – formic acid 30:20:1, detection by spraying with a solution of vanillin - ethanol - sulfuric acid 10:200:1.

J. Chil. Chem. Soc. 57, 1033-1035 (2012). HPTLC of propanolol hydrochloride (1) and flunarizine dihydrochloride (2) in combined dosage form on silica gel with methanol - toluene - ammonia 14:6:1. Quantitative determination by absorbance measurement at 267 nm. The hRf of compounds (1) and (2) were 63 and 48, respectively. Linearity was in the range of 800-4800 ng/zone for (1) and 200-1200 ng/zone for (2). Limits of detection and quantification were 25 and 75 ng/zone for (1) and 16 and 48 ng/zone for (2), respectively. Intermediate/intra-day/inter-day precision was below 2.0 % (n=6). Recovery for both (1) and (2) was between 99.3 and 100.9 %.

J. Planar Chromatogr. 25, 81-84 (2012). HPTLC of atorvastatin (1) and ezetimibe (2) on silica gel with methanol - toluene - chloroform - triethylamine 2:16:1:1. Quantitative determination by absorbance measurement at 259 nm. The hRf values of compounds (1) and (2) were 7 and 37, respectively. Linearity was in the range of 500-1500 ng/band for both (1) and (2). Intermediate/inter-day/intra-day precision was below 2 % (n=3). Mean recovery was 99.7 % for both active agents.