CBS 120, 14-15 (2018). The drugs cefixime trihydrate (CEFI) and azithromycin dihydrate (AZI) were subjected to hydrolytic degradation (with water, 0.5 N HCl or 0.5 N NaOH), oxidative degradation (with 3 % and 30 % hydrogen peroxide), thermal degradation (heated at 100 °C and 200 °C for 1 h and 2 h) and photolytic degradation (exposed to fluorescent cold white light and UV light). HPTLC of CEFI, AZI, and the degradation samples on silica gel with ethyl acetate – methanol – acetone –_x000D_ toluene – ammonia 2:10:14:1:1 to the migration distance of 80 mm. Detection of AZI by immersion into sulfuric acid reagent (1:4 in ethanol) and heating at 100 °C for 5 min. Evaluation under UV 254 nm, UV 366 nm, and white light. Quantitative determination by absorbance measurement at 235 nm for CEFI and 530 nm for AZI. Linearity was in the range of 500–2500 ng/zone for CEFI and 50–250 ng/zone for AZI. The LOD and LOQ (ng/zone) for CEFI were 58 and 175, respectively, and for AZI 3 and 10, respectively. Precision (%RSD) was <2 %. In the forced degradation studies, CEFI degraded to 4 major products under different stress conditions. AZI showed only one additional peak upon acid and neutral hydrolysis.

R.E. KAISER (Ed). Proc. of the 3rd Int. Symp. on Instr. HPTLC, Würzburg, IfC, Bad Duerkheim (1985), 277-280. Optimization of the instrumentation of quantitative HPTLC for the analysis of antibiotics by off-line use of an autosampler, a TLC scanner and a computer.

J. Microchem. 33, 209-215 (1986). TLC of daunomycin hydrochloride, adriamycin hydrochloride and their combination with dimethylsulfoxide and ascorbic acid on HPTLC silica with butanol - acetic acid - water 4:1:5 and propanol ethyl acetate - water 7:1:2. Detection by UV 254 nm.

J. Chromatogr. 403, 343-349 (1987). TLC on silica with 1. ethyl acetate - methanol - 25 % NH3 85:10:5, 2. ether - methanol - 25 % NH3 90:9:2, 3. dichloromethane - methanol - 25 % NH3 90:9:1.5, and 4. diisopropyl ether - methanol - 25 % NH3 75:35:1. Detection by drying at 110 °C for 5 min., spraying with 4-methoxybenzaldehyde - sulfuric acid - ethanol 1:1:9 and heating again for 1 min.

J. Chromatogr. 490, 395-403 (1989). TLC on silica with ethanol - water 85:5. Fluorescence enhancement by spraying with acetic acid solution and dipping into paraffin. Quantification by densitometry. Detection limit, 1 ng/mL.

Phytochemical Analysis 2, 199-203 (1991). TLC of antifungal compounds and crude plant extracts on silica with chloroform - methanol 7:3; HPTLC on diol with chloroform - methanol 98:2 and on RP-18 with chloroform - methanol 8:2. After development, the inocolum of agar with Candida albicans culture was distributed over the plate at 35°C. The bioautograms were sprayed after 12h incubation with an aq. solution of thiazolyl blue (2.5mg/mL). Clear inhibition zones can be observed against a purple background. Method also suitable for the search for antibacterial compounds as shown with Bacillus subtilis as test organism.

J. of Natural Products 55, 1441- 1446 (1992). TLC of fungal fermentation broth on silica with dichloromethane - methanol 92:8. Detection under UV 254 nm or by spraying with vanillin reagent. Isolation of trichothecene derivatives by prep. centrifugal TLC on silica with ethyl acetate - hexane 4:1.

Chinese J. Pharm. Ind. (Zhongguo Yiyao Zazhi) 26, 21-34 (1995). TLC on silica treated with 0.3 mol/L NaOH and 0.01 mol/L KH2PO4, with methanol - chloroform - NH3 2:1:1. Detection by spraying with a solution containing ninhydrin, 50 mL ethanol and 10 mL acetic acid. Quantification by densitometry at 410 nm.