VISCERAL LEISHMANIASIS IN THE BALB C MOUSE - A COMPARISON OF THE EFFICACY OF A NONIONIC SURFACTANT FORMULATION OF SODIUM STIBOGLUCONATE WITH THOSE OF 3 PROPRIETARY FORMULATIONS OF AMPHOTERICIN-B/

In this study, treatment efficacies of a nonionic surfactant vesicle f ormulation of sodium stibogluconate (SSG-NIV) and of several formulati ons of amphotericin B were compared in a murine model of visceral leis hmaniasis. Treatment with multiple doses of AmBisome, Abelcet, and Amp hocil (total dose, 12.5 mg of amphotericin B/kg of body weight) result ed in a significant suppression of parasite burdens in liver (P < 0.00 05) and spleen (P < 0.0005) compared with those of controls, with Abel cet having the lowest activity, Only AmBisome and Amphocil gave signif icant suppression of parasites in bone marrow (compared to control val ues, P < 0.005). Tn the acute-infection model, single-dose treatments of SSG-NIV (296 mg of Sb-V/kg), SSG solution (296 mg of Sb-V/kg), or A mBisome (8 mg of amphotericin B/kg) were equally effective against Liv er parasites (compared to control values, P < 0.0005), SSG-NIV and AmB isome treatment also significantly suppressed parasites in bone marrow and spleen (P < 0.005), with SSG-NIV treatment being more suppressive (>98% suppression in all three sites). Free-SSG treatment failed to s uppress spleen or bone marrow parasites. Infection status influenced t reatment outcome. In the chronic-infection model, the AmBisome single- dose treatment was less effective in all three infection sites and the SSG-NIV single-dose treatment was less effective in the spleen. The r esults of this study suggest that the antilcishmanial efficacy of SSG- NIV compares favorably with those of the novel amphotericin B formulat ions.