34] Microsealed drug delivery systems: Fabrications and performance

Abstract

The Microsealed Drug Delivery (MDD) system is a drug delivery system fabricated from a biocompatible elastomer by microdispersion of the drug reservoir, as immobilized microscopic spheres, in the cross-linked polymer matrix. Several methods of fabrication are discussed. Several physical shapes and sizes of controlled-release drug delivery devices can be fabricated from this MDD system for various biomedical applications. For example, a bandage-type transdermal therapeutic system, called Nitrodisc system, is developed from the MDD system for transdermal-controlled administration of nitroglycerin for 24-hr continuous medication in patients suffering from angina pectoris. On the other hand, for subcutaneous controlled drug administration, a cylinder-shaped subdermal implant is fabricated also from the MDD system for easy subcutaneous implantation and the controlled release of deoxycorticosterone acetate in rats at zero-order rates for duration of up to 129 days for cardiovascular pharmacology studies. The chapter presents two examples of the many controlled-release drug delivery devices that can be fabricated from the patented MDD system.