Microencapsulation of self-microemulsifying system: improving solubility and permeability of furosemide.

The primary goal of this study was to formulate Ca-pectinate microcapsules with self-microemulsifying core to enhance the solubility and permeability of BCS class IV drug furosemide. An Inotech IE-50R encapsulator equipped with a concentric nozzle was utilized to transform liquid self-microemulsifying system (SMES) to solid microcapsules. Self-microemulsifying core was optimized with respect to drug loading capacity and encapsulation efficiency and evaluated for its impact on furosemide permeability through rat small intestine and Caco-2 cell monolayers. Retention of the core phase was considerably improved (up to 70-80%) by optimization of the SMES and microcapsules' drying process. Incorporation of furosemide in self-microemulsifying core of microcapsules resulted in improved permeability and drug release characteristics in comparison to microspheres (without SMES in the core). The obtained results illustrate the prospective use of microcapsules with self-microemulsifying core for the delivery of compounds with poor biopharmaceutical properties via the oral route. Copyright (c) 2009 Elsevier B.V. All rights reserved.