Soluplus ® , Eudragit ® , HPMC-AS foams and solid dispersions for enhancement of Carvedilol dissolution rate prepared by a supercritical CO 2 process

Abstract

The present work is aimed towards designing advanced materials by means of sustainable processes. In that sense, the utilization of supercritical CO 2 (scCO 2 ) for processing of pharmaceutical polymers (Soluplus ® , Eudragit ® , and hydroxypropyl methylcellulose acetate succinate), alone and with an addition of cardiovascular drug Carvedilol, was explored. Employed single-step static scCO 2 process (pressure of 30 MPa and temperature of 100 °C for 2 h) enabled fabrication of solvent-free polymeric foams and Carvedilol solid dispersions with controlled microstructure and average pore diameter of 101–257 μm suitable for application in the pharmaceutical industry. ScCO 2 did not remain in the foams after processing or affected the polymer composition, while Carvedilol formed hydrogen bonds with the polymers. Carvedilol was molecularly dispersed in the fabricated solid dispersions and its transition from the crystalline to amorphous form was complete. Korsmeyer-Peppas model was successfully used for the mathematical description of Carvedilol dissolution from solid dispersions. The dissolution rate of Carvedilol in acidic medium was significantly enhanced by its dispersion in tested polymers using the proposed high-pressure method.