In: Anatomy and Physiology
Describe a drug delivery system that is responsive to external stimuli and how it works.
Stimulus controlled Drug Delivery System (DDS) are used nowdays to deliver drugs to the targeted organs. External stimulus like temperature, light, pH can be used to control the drug release from the drug delivery systems. The drug release from DDS depends upon the type of polymer being used i.e the drug carriers to the target sites and selective delivery of drugs.
Temperature sensitive polymer like Poly N isopropylacrylamide is used in some DDS, this polymer has phase transition temperature at which the properties of system change and solubility of drug embedded in the polymer also changes. Due to change in temperature the drug starts to release from the membrane of the system and enters the target site to show it's therapeutic actions. The permeation rate of the drug from the DDS depends upon the temperature changes. The drug is mixed with polymers to form DDS like liposomes. These temperature sensitive liposomes based upon thermosensitive polymers are used in chemotherapy for some tumors.