The stability of amphotericin B in 5%, 10%, 15%, and 20% dextrose injection was investigated. The dextrose solutions were prepared in triplicate from sterile water for injection and 70% dextrose injection and placed in empty 50-mL polyvinyl chloride bags. The pH of each solution was determined before amphotericin B was added to a concentration of approximately 100 micrograms/mL. The bags were stored at 15-25 degrees C and protected from light. Three 1-mL samples were taken from each bag at various times up to 24 hours. One sample was analyzed for precipitation and color and pH changes. Two samples were analyzed in duplicate by stability-indicating high-performance liquid chromatography. No visual changes were observed, and pH did not change substantially. The mean amphotericin B concentration was greater than 90% of the initial concentration at each sampling time. However, the drug concentration in 3 of the 27 samples from the admixtures with 10% dextrose injection and 5 of the 27 samples from the admixtures with 20% dextrose injection fell below 90% of the initial concentration. Amphotericin B 100 micrograms/mL was stable in 5%, 10%, 15%, and 20% dextrose injection when stored for up to 24 hours at 15-25 degrees C and protected from light.