Paper chromatographic determination of chlortetracycline.
Chlortetracycline was successfully separated from its degradation products and from other tetracyclines on a paper chromatogram previously impregnated with a mixture of edetate disodium and urea solution in pH 5.0 McIlvaine buffer. Chlortetracycline separation from its degradation products and from both tetracycline and oxytetracycline was attributed primarily to the complexation of these antibiotics with urea and edetate on the chromatogram. The separated spots were located under UV light, and their Rf values were calculated. Chlortetracycline recovery from the paper chromatogram was satisfactory (98.3 +/- 0.002%). The developed method was successfully applied to the determination of chlortetracycline in various dosage forms. In addition, the method was adequate for monitoring chlortetracycline hydrochyloride stability in aqueous solutions.