MICROBIOLOGICAL ASSAY METHODS OF CEFOTETAN (YM09330) CONCENTRATIONS IN BODY FLUIDS

• Published in: CHEMOTHERAPY Vol. 30; no. Supplement1; pp. 98 - 105
• Main Authors: KOMIYA, MASAYUKI, KIKUCHI, YASUHIRO, TACHIBANA, AKIO, YANO, KUNIICHIRO
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Chemotherapy 1982
• ISSN: 0009-3165; 1884-5894
• DOI: 10.11250/chemotherapy1953.30.Supplement1_98

The microbiological assay methods for antibiotic concentration in body fluids after treatment of cefotetan (CTT, YM09330), a new semisynthetic cephamycin antibiotic, were discribed. The suitable conditions for the assay of the concentration resulted from using of E.coli NIHJ as the test organism and sensitivity test agar as the medium, in which 1% of over-night precultured Trypticase soy broth inoculated with the test organism was added. For the determination of the antibiotic concentration in biological specimens, three assay methods, thin-layer cup, thin-layer disc and agar well method, gave the suitable long-range standard curves and revealed good sensitivity. Cefotetan standard curve was not markedly influenced by pH of the medium and of the diluent buffer solution. By the thin-layer disc method, the detectable concentrations of cefotetan were, at the lowest, 0.2μg/ml for 1/10M phosphate buffer pH 7.0, and 0.78μg/ml for human plasma, Consera and Moni-trol I when used as the diluent for the standard solution. The inhibition zone sizes of cefotetan dissolved in human plasma, Consera and Moni-trol I were smaller than those in phosphate buffer solution at pH 7.0. However, the standard curves of cefotetan using human plasma and Consera as the diluent showed almost the same figure. The concentrations of cefotetan in urine and bile detected by the bioassay method were in good agreement with those obtained by HPLC method. Cefotetan was stable in phosphate buffer solution at pH 7.0, human plasma and human urine at-20°C over a period of 30 days. In rat bile, cefotetan was unstable somewhat at 4°C but was stable during 7 days storage at-20°C.