Development of Enzalutamide Solid Dispersion Loaded Tablet with Enhanced Solubility

Abstract

The objective of this study was to develop a novel enzalutamide tablet formulation with enhanced solubility and bioavailability, and inhibited recrystallization. Kollidon VA64 was selected as a soluble polymer for preparing enzalutamide solid dispersions. Solid dispersions with different enzalutamide to Kollidon VA64 weight ratios were prepared via solvent evaporation method. The enzalutamide solid dispersion consisting of enzalutamide and Kollidon VA64 at a weight ratio of 1:1, exhibited an excellent dissolution rate and potent inhibition of recrystallization. Enzalutamide solid dispersions were characterized by scanning electron microscopy, powder X-ray diffractometry, differential scanning calorimetry, and in vitro dissolution studies. The 1:1 solid dispersion exhibited excellent productivity, an elevated dissolution rate, and recrystallization inhibition. Therefore, enzalutamide solid dispersion loaded tablets were prepared and their dissolution was evaluated compared to a commercial product (Xtandi® soft capsule). The selected tablet formulation containing enzalutamide solid dispersion exhibited a higher dissolution rate in pH 1.0 solution than did the Xtandi® soft capsule, and prevented recrystallization of the enzalutamide. This research suggests that enzalutamide-containing solid dispersion tablets could be the most effective method to date for improving the dosing compliance of Xtandi® soft capsules, improving the dissolution rate of enzalutamide, and preventing recrystallization.