STIMULI-INDUCED PULSATILE OR TRIGGERED RELEASE DELIVERY SYSTEMS IN DEVELOPMENT OF NOVEL DRUG DELIVERY DEVICES FOR BIOACTIVE COMPOUNDS

Many vital functions are regulated by pulsed or triggered release of bioactive substances at a specific site and time. Thus it is important to develop new drug delivery devices to achieve pulsed delivery of a certain amount of drugs in order to mimic the function of the living systems to minimize the undesired side effects. This review will cover methods that have been developed to control drug delivery profile with different polymeric systems. The pulsed or triggered delivery systems are designed to alter their rate of drug delivery in response to stimuli such as changes in a specific molecule, a magnetic or electric field, temperature, light or mechanical forces. Such systems are suitable for the release of therapeutics that benefit from non-linear plasma concentrations. In this article, several types of drug delivery systems which cause the pulsed or triggered release of bioactive compounds due to certain external stimuli, mostly focuses on thermally-, electrically- and magnetically- induced release are described in detail. These system have the potential to improve the quality of life for patients undergoing therapy with a variable dosing regime. The recent patents on various delivery systems which release the active compounds only with the external stimuli are described in detail. While newer and more powerful drugs continue to be developed, increasing attention is being given to the methods by which these active substances are administration.