The stability of itraconazole in an extemporaneously compounded oral liquid formulation was studied. A suspension was prepared from the beads contained in commercially available 100-mg itraconazole capsules and sufficient Simple Syrup, NF, to make a final volume of 60 mL. The final concentration of itraconazole in the suspension was 40 mg/mL. Three identical volumes of each suspension were prepared and stored in 2-oz capped, amber glass prescription bottles and refrigerated at 4 degrees C (range, 2-6 degrees C). Immediately after preparation and at 7, 14, 21, 28, and 35 days, samples were visually inspected and assayed in duplicate by high-performance liquid chromatography; the pH of the samples was also determined. On day 35, the mean +/- S.D. percentage of initial itraconazole concentration remaining in the three suspensions was 95.3 +/- 2.2%. The color, odor, and pH of the samples did not change appreciably over the study period. Itraconazole 40 mg/mL in an oral liquid compounded from simple syrup and beads from capsules, stored in amber glass bottles, was stable for 35 days at 4 degrees C.