Abstract G-28, IPC (2005). HPTLC of rosuvastatin on silica gel with chloroform - methanol - toluene 3:1:1. Quantitative determination by absorbance measurement. The hRf value of rosuvastatin was 53, recovery rate was between 98-102 %, LOD was 8 ng/spot and LOQ 26 ng/spot.

Hosp. Pharm. (Zhongguo Yiyuan Yaoxue Zazhi) 25 (9), 894-896 (2005). TLC of the extracts on silica gel plates with acetone - ethanol - hydrochloric acid 10:6:1. Detection by spraying with potassium iodobismuthate solution. Identification by comparison with the standard. Quantification by densitometry at 510 nm. Validation of the method by investigation of linearity range (2.2 µg - 10.8 µg, r = 0.9994); precision (RSD = 1.05 %, n = 5); reproducibility of five time assay towards the same sample (RSD = 0.31 %); and standard addition recovery (98.1 %, RSD = 2.15 %, n = 5). The results for five real life samples are given.

J. Planar Chromatogr. 18, 34 -38 (2005). Considering the latest technical and methodological developments, modern high-performance thin-layer chromatography, also known as planar chromatography, is a reliable and powerful analytical technique, in full compliance with current good-manufacturing practice (cGMP). With the proper equipment TLC is the method of choice when many samples must be analysed at low cost per sample. Advantages of HPTLC are shown in the analysis of botanicals: 1) Identification (separation of Stephania tetrandra root extracts with tetrandrine as standard on silica gel with toluene - ethyl acetate - methanol -ammonia 100:100:50:3; detection under UV at 254 and 366 nm, under white light after derivatization with iodine, and under UV at 366 nm after derivatization with anisaldehyde. 2) Semi-quantitative assessments in process control and stability tests (separation of fatty acids of Saw Palmetto products on RP-18 by two fold development with dichloromethane - acetic acid - acetone 2:4:5. 3) Quantitfication of marker compounds, like curcumin measured at 366 nm/>400 nm on silica gel with toluene - acetic acid 4:1. 4) Choice of stationary phase (separation of flavonoids on conventional TLC plates and on HPTLC plates with formic acid - water - ethyl methyl ketone - ethyl acetate 10:10:30:50 and detection with natural products reagent; switching to HPTLC reduced analysis time to a quarter and gave sharper bands). 5) Choice of mobile phase; 6) Derivatization and 7) Chromatogram evaluation.

J. Planar Chromatogr. 18, 57-60 (2005). HPTLC of the organic components of composite modified double-base (CMDB) propellants (with nitroglycerine, carbamite, diethyl phthalate, dibutyl phthalate, 2-nitrodiphenylamine as standards) on silica gel with chloroform - cyclohexane 7:3. Detection under UV light at 254 nm. Densitometric scanning in absorbance mode at 210 nm. Comparison of the UV spectra of the separated compounds with those of the standards.

J. Liq. Chrom. & Rel. Technol. 26, 3453-3462 (2003). HPTLC of caffeine and acetaminophen on silica gel in a saturated twin-trough chamber with ethyl acetate - glacial acetic acid 19:1. Quantification at 254 nm. Diphenhydramine, pseudoephedrine, and acetaminophen were well separated from the caffeine zone. Precision (relative standard deviation) was 1.19 %; limit of detection was 0.2 µg for caffeine and 0.08 µg for acetaminophen; precision of duplicate samples (RSD) ranged from 0.95 to 7.56 %.

Chromatographia 64 (1-2), 101-104 (2006). TLC of metformin and glyburide in three different formulations of Glucovance®, on silica gel with water - methanol - ammonium sulfate 4:2:1. Rf value of metformin was 0.43 and of glyburide 0.64. Quantitative determination by absorbance measurement at 237 nm. The linear regression data for the calibration plot showed a good relationship with r = 0.99581 and 0.99982 for metformin and glyburide, respectively. The method was validated for precision and recovery. The limits of detection and quantification were 25 and 84 ng/spot for metformin and 12 and 41 ng/spot for glyburide, respectively. Stability study has been carried out for samples and standard solutions.

Indian Drugs 42 (9), 592-596 (2005). HPTLC of rutin in Ginkgo biloba from a solid dosage form, on silica gel with n-butanol - n-propanol - chloroform - acetic acid-water 4:1:2:1:1 containing 1 % formic acid. Quantitative determination by absorbance measurement at 254 nm. Rf value of rutin was 0.24. The method was linear in the range of 30-70 ng/µL. No interference was observed from excipients present in solid dosage form.

J. Planar Chromatogr. 19, 371-377 (2006). HPTLC of five isoflavone products and 2-phenylchromone as reference standard on silica gel, pre-washed with acetonitrile, in an unsaturated chamber, twice with chloroform or dichloromethane. Determination by absorbance measurement at 280 nm. Preparative layer chromatography on silica gel. A new device for isolation of sythesis products in sub-milligram amounts was successfully employed.