TLC in pharmacy: erythromycin. Deutsche Apotheker Zeitung 131, 2710-2711 (1991). TLC of erythromycin on silica with methanol – ethyl acetate 9:1. Visualization by spraying with ammonium-8-anilinonaphthaline-1-sulfonate, heating at 80 °C for some min and under UV 365 nm or by spraying with K2Cr2O7 – sulfuric acid reagent, heating at 90 °C for some min; observation under day light.

J. Planar Chromatogr. 7, 297-300 (1994). TLC for rapid and simple control of the purity of tetracyclines on silica with dichloromethane - methanol - water 60:35:5 for chlortetracycline and dichloromethane - methanol - water 59:35:6 for the other tetracyclines. Before use the plates were sprayed with a 10% solution of disodium EDTA, the pH of which had been adjusted with a 40% solution of sodium hydroxide to pH 8.0 for tetracycline, chlortetracycline, and demeclocycline and to pH 9.0 for oxytetracycline, doxycycline, and metacycline. Visualization and semi-quantitative assessment under UV 365 nm.

J. AOAC Int. 79, 1263-1268 (1996). TLC separation of erythromycin, tylosin and 11 other drugs (oxytetracycline, chlortetracycline-HCl, furazolidone, nitrofurazone, nitrofurantoin, sulfathiazole, sulfadiazine, sulfamerazine, amprolium, olaquindox, ronidazole) on silica with chloroform - methanol 10:1 with traces of NH3. Detection under UV 254 and 366 nm; also spraying with 10 % sulfuric acid in ethanol and heating at 120°C for 3 min.

Part III: Quantitation and evaluation of cephalosporins. J. Planar Chromatogr. 12, 114-119 (1999). Scanning densitometry for direct quantitation of cefoxitin, cefpirome, cefotaxime, cefoperazone, cefepime, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, cefotetan, cephalothin, and cefazolin on reversed-phase hydrocarbon-impregnated HPTLC silica gel plates without prior solvent elution. The samples remained as a single spot centered about the point of application, thereby facilitating direct quantitation by densitometry at different wavelengths.

J. Planar Chromatogr. 15, 187-191 (2002). TLC of flumequine and doxycycline on silica gel with and without a concentrating zone (after predeveloping with hexane and acetone) with 0.05 M citric acid - methanol - 2-propanol 1:3:1. Detection under UV 366 and 254 nm and by densitometry at 360 nm (for doxycycline) and at 325 nm (for flumequine). Bioautography by dipping the developed plates in a nutrient medium inoculated with Bacillus subtilis spore suspension and incubated overnight at 28°C. The plates were then sprayed with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) solution and incubated for approximately 30 min.

J. AOAC Int. 88, 1555-1561 (2005). HPTLC of chloramphenicol on silica gel in a horizontal developing chamber (36 applications per plate) using n-hexane -ethyl acetate 7:13. Quantitative determination by absorbance measurement at 280 nm. Mean recovery was 95.8 %, and the coefficient of variation was 5.8 %. The detection limit was 3 ng, and the quantitation limit 10 ng.

J. Chromatogr. B 877 (29), 3719-3723 (2009). HPTLC of gemifloxacin mesylate in human plasma, extracted with chloroform - acetic acid 59:1, on silica gel with ethyl acetate – methanol - ammonia 8:4:3. The hRf value of gemifloxacin mesylate was 33. Quantification by densitometry at 254 nm. The calibration curve was established in the range of 50 to 600 ng/spot. Recovery of gemifloxacin mesylate was between 80.0 and 86.2 %. The stability of gemifloxacin mesylate in plasma was confirmed with samples submitted to three cycles of freeze–thawing at -20 °C, and with samples stored on the bench for 12 h.

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.