Ultrasonic atomization and polyelectrolyte complexation to produce gastroresistant shell-core microparticles

In this study ultrasound-assisted atomization technique was combined with two-stages polyelectrolyte complexation to produce enteric shell-core microparticles encapsulating a non-steroidal, anti-inflammatory gastrolesive active ingredient indomethacin. In particular, a solution of the anionic biopolymer alginate, containing indomethacin, was sprayed in fine droplets which were complexed with a cationic (meth)acrylate copolymer, Eudragit((R)) E 100, which, in turn, was complexed by the anionic copolymer Eudragit((R)) L30D-55. The first complexation stage was applied to achieve a high drug encapsulation efficiency; the second one to assure good gastroresistance feature. The novel protocol has been found more effective in terms of loading, encapsulation efficiency, and enteric properties during in vitro release tests, than conventional procedures which involved alginate cross-linking by charged ions. Furthermore ultrasonic atomization-polyelectrolytes complexation preparation approach was performed using mild conditions, aqueous solutions, in the absence of organic solvents and chemical cross-linkers. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42976.