Mathematical model of a hybrid dispersed network-membrane-based controlledrelease system

A mathematical model with an exact solution is presented For the controlled release of a drug from a hybrid dispersed network-membrane based system. B oth hollow fiber and Rat membrane device geometries are considered. The res ervoir is loaded with a drug dispersed in a liquid phase. This reservoir is bounded by a microporous membrane, the pores of which are filled with liqu id immiscible with the reservoir phase liquid. The drug dissolves from the solid network into the reservoir liquid and migrates through the reservoir toward the microporous membrane. At the interface between the reservoir and the pore, the solute partitions between the reservoir and the pore liquid phases, before diffusing outward through the membrane pore. Experimental re sults are in close agreement with the release profiles predicted by the mat hematical model. Parametric studies reveal the interaction between system p arameters and the controlled release behavior. The presence of a dispersed drug phase in the reservoir results: in the release of drug for an extended time. The release rate of the drug may be controlled by its rate of diffus ion through the membrane pores or by its rate of dissolution into the reser voir liquid. (C) 2001 Elsevier Science B.V. All rights reserved.