Evaluation of the hyperbranched polymer Hybrane H1500 for production of matricial controlled-release particles by hot-melt extrusion

Extrudates of the hyperbranched polymer Hybrane H1500 prepared by hot melt extrusion, with five particle sizes (from <250 μm to 1.5–2.0 mm) and three drug content (10, 20 and 30%) of acetaminophen or caffeine, were evaluated in this study as potential multiparticulate controlled release systems. Hybrane H1500 extrudates (of very low porosity), experienced a very slow hydration, with a limited swelling capacity, and they do not behave as true gels when fully hydrated. Hot melt extrusion provokes the conversion of the acetaminophen into an amorphous state inside the extrudates, whereas for those containing caffeine, some crystals remain for the highest drug proportions (20 and 30%). From both drug extrudates a wide range of dissolution profiles are obtained. Drug release rate depends mostly on extrudate particle size, and in those extrudates containing caffeine, a slight effect of the drug proportion is observed. Dissolution profiles’ kinetic analysis suggests that drug release is controlled by the diffusion of the drug through the polymeric hydrated structure, although this mechanism is only clearly and efficiently displayed for the greatest extrudate particles (1.5–2.0 mm).

Figure optionsDownload high-quality image (191 K)Download as PowerPoint slide