EFFICACY OF NS-718, A NOVEL LIPID NANOSPHERE-ENCAPSULATED AMPHOTERICIN-B, AGAINST CRYPTOCOCCUS-NEOFORMANS

In vitro and in vivo efficacies of NS-718, a lipid nanosphere-encapsul ated amphotericin B (AMPH-B), have been studied. Of the tested AMPH-B formulations, NS-718 had the lowest MIC for Cryptococcus neoformans. I n a murine model, low-dose therapy (0.8 mg/kg of body weight) with NS- 718 showed higher efficacy than that with AmBisome. High-dose therapy (2.0 mg/kg) with NS-718 was much more effective than those with Fungiz one and AmBisome. In mice treated with a high dose of NS-718, only a f ew yeast cells had grown in lung by 7 days after inoculation. A pharma cokinetic study showed higher concentrations of AMPH-B in lung followi ng administration of NS-718 than after administration of AmBisome. Our results indicated that NS-718, a new AMPH-B formulation, is a promisi ng antifungal agent for treatment of pulmonary cryptococcosis and coul d be the most effective antifungal agent against C. neoformans infecti ons.