A stability study of chloramphenicol in topical formulations

Abstract

Abstract The stabilities of several chloramphenicol preparations have been investigated at ambient temperatures. The B.P.C ointment and eye ointment were stable over 2 years. The remainder retained more than 90% of their potencies after the following periods: ear drops B.P.C., 2 years, Drug Tariff cream, 5 months and eye drops B.P.C., 3 to 4 months. 15% hydrolysis occurred after autoclaving the eye drops, and 3 to 4% after heating with a bactericide. The latter sterilization process is recommended. Two assay procedures were employed, one estimating residual chloramphenicol by ultraviolet spectrophotometry after separation from decomposition products by thin layer chromatography and the other determining the main degradation product (1-p-nitrophenylpropan-1,3-diol-2-amine) colorimetrically.