Effects of Sterols on the Therapeutic Efficacy of Liposomal Amphotericin B in Murine Candidiasis

Incorporation of amphotericin B (AMP-B) into phospholipid vesicles (liposomes) has been shown previously to decrease AMP-B toxicity while retaining the antifungal efficacy of the drug. In this report, the role of sterols in the formulation of liposomes as well as in their effectiveness in the treatment of murine candidiasis have been investigated. The presence of ergosterol or cholesterol at different lipid ratios did not augment the encapsulation efficiency of AMP-B as compared with vesicles containing phospholipids alone. There was no significant difference in the survival time of mice infected with Candida albicans treated with sterol-containing vesicles compared with those treated with sterolfree vesicles. These findings suggest that the sterol-free liposomes might be of advantage for delivering AMP-B because of its simple formulation, lack of toxicity, and ease of preparation.