Abstract
The effect of a new penicillin derivative, aminocyclohexyl penicillin (AC PC) was studied with the results which may lead to the following conclusion.
1) Sensitivity of various clinically isolated organisms: The minimal inhibitory concentration of AC PC was measured by an agar plate dilution method. The MIC of AC PC against 80 strains of coagulase positive staphylococcus aureus isolated from otorrhoea was distributed over a range of 0.39 to≥100 mcg/ml, with a peak being observed particularly at 6.25 mcg/ml. While, that of AC PC inhibited in most of agar cultures of proteus mirabilis, klebsiella pneumoniae and escherichia coli, except pseudomonas aeruginosa, against while the MIC of AC PC ranged from 25 to≥100 mcg/ml.
2) Concentration in blood: The maximal level reached 16 mcg/ml on the average one hour after a single oral administration of AC PC 500 mg to 3 healthy adults, and the level was still 0.3 mcg/ml four hours after the oral administration.
