Studies showed that when the concentration of AmB in mixtures prepared with IL containing 20% soybean oil was reduced to 0.6 mg/ml, a precipitate was observed in all mixtures with more than 30 ml of IL/100 ml of the total volume.
With mixtures prepared with IL containing 10% soybean oil and having a final AmB concentration of 1.2 mg/ml, a precipitate was observed in all mixtures containing more than 30 ml of IL/100 ml of the total volume; when the concentration of AmB was 0.6 mg/ml, a precipitate occurred in mixtures with more than 40 ml of IL/100 ml of the total volume.
The observation by Trissel that the precipitate consists of particles greater than 10 μm in size suggests that even without centrifugation, certain AmB-IL mixtures might be unsafe for human administration. It has also been suggested that the formation of these aggregates might result in decreased antifungal activity.
