抄録
Antibacterial activity, stability of solution and clinical effect of new antibiotic, PIPC were evaluated. The results obtained are as follows.
1) In vitro antibacterial activity: The minimal inhibitory concentration (MIC) of PIPC was measured by an agar plate dilution method using heart infusion agar. PIPC revealed an excellent, broad spectrum antibacterial activity against 13 standard strains of various bacteria. PIPC had same antibacterial spectrum like those of other penicillin antibiotics. The MIC of PIPC against 60 strains of Staphylococcus aureus isolated from otorrhea was distributed over range of 0.78 to 50 μg/ml, with a peak being observed particularly at 3.13μg/ml. The MIC of PIPC was 1.56 to≥100μg/ml against Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae. The MIC against 60 strains of Pseudomonas was 1.56 to ≥100μg/ml, showing its peak at 6.25μg/ml.
2) Stability of PIPC solution: As to the stability of 10 mg/ml of PIPC there was no change in its color, pH and antibacterial activity when the solution was kept at 5°C and 37°C for 12 days.
3) Results of clinical treatment: When administration of PIPC was applied locally in 32 cases of the acute or chronic purulent otitis media, it was good in 22 cases, fair in 2 cases and poor in 8 cases. When the cases in which it was good and fair were considered together, the rate of effectiveness was 75 percent. No side effect was observed when PIPC solution was locally used.
