Stability of four antifungal antimicrobics in vitro.

The stability of amphotericin B, amphotericin B methyl ester, 5-fluorocytosine, and miconazole was assessed under conditions encountered in bioassay and susceptibility testing in vitro. Although the amphotericins were labile as compared with other drugs, tests should be reliable with all four antimicrobics in view of the rapid action of the polyenes and the relatively slow action of 5-fluorocytocine and miconazole.