Nanonized itraconazole powders for extemporary oral suspensions : role of formulation components studied by a mixture design

Itraconazole (ITZ) nanocrystal-containing powders were prepared through the combined use of high pressure homogenization (HPH) and spray drying (SD). These powders were intended as base materials for the preparation of extemporary oral suspensions of the drug. The role and the effect of stabilizers on the size of re-dispersed particles were studied using a mixture design and a Scheffé model relating the dried nanosuspension composition to the mean particle diameters. The homogenization process required a surface active agent (Tween 20) to obtain the efficient comminution of itraconazole micronized powder. SD was carried out on ITZ nanosuspensions after addition of a cellulose derivative (Methocel® E5) that allowed the prompt re-dispersion of nanoparticles under "in use" conditions. The powders obtained by drying of homogenized systems showed in vitro dissolution profile faster than that of the micronized drug, suggesting a potential ameliorated GI absorption of itraconazole released from the nanosuspensions.