Modified Release Delivery Systems
INTRODUCTION Modified release drug delivery systems are rapidly gaining importance in the pharmaceutical industry. The ability to effectively control the rate of drug release as well as the location of drug released are important factors to consider to maximize the therapeutic benefit of a drug. This is especially important in the delivery of protein and other biological therapeutics, which typically have a short circulation half-life that can be extended with modified release technology. Spatiotemporal control offers better patient compliance with less-frequent dosing and decreased systemic side effects that come with better dose control. This is also very applicable to drugs like chemotherapeutics, which can potentially be delivered in such a way that meter drug dosing local to the cancer and not the entire patient, thus minimizing the debilitating side effects of the drug. Additionally, control of drug distribution could enable physicians to use more potent doses that would be toxic if given systemically. This chapter will examine drug delivery systems that can modulate drug concentration, and provide an overview of device designs and parameters that can be tuned to achieve the desired release schedule.