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MICROBIOLOGICAL ASSAY OF JOSAMYCIN
Author(s) -
Bergan Tom,
Øydvin Bjorg
Publication year - 1972
Publication title -
acta pathologica microbiologica scandinavica section b microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0365-5563
DOI - 10.1111/j.1699-0463.1972.tb00134.x
Subject(s) - josamycin , chemistry , incubation , bioassay , chromatography , micrococcus luteus , incubation period , antibiotics , biochemistry , biology , erythromycin , escherichia coli , gene , genetics
A sensitive bioassay for josamycin was obtained by an agar cup procedure using Micrococcus luteus CQ , 70 ml Mueller Hinton Medium (Difco) per 14 cm diameter plates, 5 hours prediffusion, and over night incubation at 37°C. This procedure allows measurements in the range of 0.01–4.0 μ/ml josamycin base. Josamycin activity was enhanced by high pH values. NaCl and NaHCO 3 had little influence on josamycin activity, whereas CaCl 2 was markedly inhibitory. Josamycin base was relatively stable in acid milieu. No inactivation was found after 6 weeks in serum at —70°C, or for 3 hours either in a pH 7.0 phosphate buffer solution or in a simulated intestinal fluid T. S. of the United States Pharmacopeia (USP XVIII). Only 35 per cent inactivation was found after 3 hours storage at room temperature in a simulated gastric fluid (USP XVIII).