MAGNETICALLY MODULATED RELEASE FROM IMPLANTABLE DEVICES.

In the past few years, there have been many recent advances in the development of polymeric drug delivery systems. However, nearly all of these systems release drugs at decreasing, or at best, constant rates. There has been no way to increase release rates on demand, nor any way to externally control drug administration once the release process from the implanted polymer matrix has commenced. The necessity of enhanced delivery by demand is manifested in hormonal delivery of substances such as insulin. In diabetes, augmented delivery of insulin is required for short periods associated with meals. Recent studies in our laboratory suggest the feasibility of delivering insulin and other macromolecues at increased rates on demand. The polymeric device consists of small magnetic beads embedded in the polymer matrix along with the drug. Release rates can be enhanced when desired by an oscillating external magnetic field. In this study we report the function in vivo of this magnetically modulated system.