Part 1. Thin-layer chromatographic tests. (Hungarian). Acta Pharmaceutica Hungarica 60, 197-204 (1990). TLC of chloropromazine, levomepromazine, promethazine and trifluoperazine on silica with cyclohexane - benzene - diethylamine 75:15:10 (first dim.), cyclohexane - acetone - diethylamine 80:10:10 (second dim.) or methanol - 25% NH3 90:10, on aluminiumoxide with benzene - acetone 95:5 or 85:15. Visualization under UV 254 nm.

J. Planar Chromatogr. 4, 218-222 (1991). HPTLC of metoprolol (1-(isopropylamino)-3-[4-(2-methoxyethyl)phenoxy]-2-propanol, 1-(isopropylamino)-3-[4-(2-hydroxyethyl)phenoxy]-2-propanol on silica with three consecutive developments in chloroform – dichloromethane – benzene – cyclohexane 7:65:13. resp. with two consecutive developments in chloroform – dichloromethane – benzene 6:3:1. Developing chamber was protected from light by covering with aluminium foil. Silica gel HPTLC plates were impregnated with BHT prior to spotting by dipping into a solution of BHT (0.5-4.5%) in acetone. Quantification by fluorescence scanning at 323/>400 nm.

J. Planar Chromatogr. 6, 337-340 (1993). HPTLC of sulfameter (4-amino-N-(5-methoxy-2-pyrimidynyl)benzenesulfonamide), sulfamethoxazole and sulfisoxazole on (prewashed) silica with chloroform - ethyl acetate 4:6, horizontal development. Quantification by densitometry at 270 nm (absorbance).

Eastern Pharmacist 37, 179-180 (1994). HPTLC of anti-anxiety drugs amitriptyline and clordiazepoxide in tablets on silica (prewashed with methanol) with ethyl acetate - methanol - diethylamine 190:10:1. Quantification by densitometry at 245 nm. Recovery 100.8 - 102%.

J. Planar Chromatogr. 8, 314 - 318 (1995). Analysis of chloramphenicol-monosuccinate and gentamycin as example of the use of quantitative TLC for quality control of freshly produced drugs and those stored long-term. - TLC of chloramphenicol-monosuccinate sodium on silica with n-butyl acetate - acetic acid 24:1; quantification by densitometry at 280 nm. TLC of gentamycin on silica with the lower layer of a mixture of chloroform - methanol - NH3 conc. (after shaking) 1:1:1. Detection after derivatization with fluorescamine; quantification by densitometry (fluorescence) at 366 nm. Convenient, fast, cost-effective, simple screening procedure.

by thin-layer chromatography.) (Chinese). J. Chinese Trad. Patent Med. (Zhongchengyao) 17 (4), 1-3 (1995). TLC on silica with the upper phase of benzene - ethyl formate 4:1. Detection by exposure to NH3 vapor. Discussion of the dosage form by comparison of the chromatograms.

J. Planar Chromatogr. 10, 303-304 (1997). HPTLC of diltiazem (3-(acetyloxy)-5-[2-(dimethylamino)ethyl]-2,3-dihydro-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one) and desacetyldiltiazem on silica with chloroform - cyclohexane - toluene - diethylamine 30:20:20:3. Detection under UV 254 nm. Quantification by densitometry at 240 nm (absorbance). RSD of 2.2 and 0.9% (for two samples containing 0.23 and 0.68% of DAD); recovery (450 ng of D) was 99.7%; repeatability was 1.7%. Also published in Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 1-4 (1997).

HPTLC with ultraviolet absorption densitometry on preadsorbent layers. Acta Chromatographica No. 7, 124-128 (1997). HPTLC on silica with ethyl acetate - acetic acid 19:1 in a vapor-equilibrated, paper-lined chamber, and on RP-18 with methanol - 0.5 M sodium chloride solution 11:9. Detection and quantification under UV 254 nm. Detection limit 0.25 µg. Recoveries and standard deviation are typical for those obtained for routine use of the method in a pharmaceutical laboratory. The TLC method involves very low solvent usage on a per sample basis compared to HPLC, leading to savings in purchase and disposal costs, and the ability to analyze multiple samples on a single plate containing only three standard zones permits very high sample throughput. Use of both NP- and RP-TLC provides excellent confirmation of qualitative and quantitative results.