Comparative in vitro effects of liposomal amphotericin B, amphotericin B-deoxycholate, and free amphotericin B against fungal strains determined by using MIC and minimal lethal concentration susceptibility studies and time-kill curves.

Multilamellar liposomal amphotericin B (L-AmB) was generally less active in vitro against yeast strains than was amphotericin B-deoxycholate or free amphotericin B, although continual agitation of the broth disproportionately increased the activity of L-AmB. Time-kill studies also demonstrated a slower onset of action of L-AmB and supported the hypothesis that liposomes may act as reservoirs for free amphotericin B, which is the active moiety.