Ethylcellulose microparticles: a review.

Ethylcellulose (EC) based microencapsulated drug delivery systems are being extensively studied throughout the world for achieving extended drug release and protecting the core substance from degradation. The in vitro evaluation of EC microcapsules have elucidated that their particle characteristics are very useful to control drug release behavior, since these enable drugs to be released at a certain controlled release rate based on the characteristics of drug-EC linkage. This review encompasses microencapsulation techniques, core substances and other fundamentals involved in the preparation and characterization of EC microcapsules. EC microcapsules can be considered as mini-osmotic pumps. The release kinetics for EC microcapsules can be fine-tuned by altering osmolality of the dissolution medium or formulations and EC film mechanical characteristics by selecting appropriate EC molecular weights (viscosity), EC substitution grades, coating weights, and pore formers.