Role Of Novel Polymer In Drug Delivery System

This review focus on the role of polymers used in pharmaceutical drug delivery of therapeutic agents. The polymers are used as carriers for delivery of drug at target site. Biodegradable polymers are widely used in delivery of drugs at specific site of the body because they can be degraded at constant rate of drug release. Natural polymers are also used for drug delivery at predetermined rates. The release mechanism of the drug from these polymers is by Degradation, Diffusion and Swelling. For controlled drug delivery of the therapeutic agents, they are used in pharmaceutical industry as binders, as film coating to mask the unpleasant taste, to enhance the drug stability and to modify the release characteristics of the drug. Polymers are being used extensively in drug delivery due to their surface and bulk properties. They are being used in drug formulations and in drug delivery devices. These drug delivery devices may be in the form of implants for controlled drug delivery. Polymers used in colloidal drug carrier systems, consisting of small particles, show great advantage in drug delivery systems because of optimized drug loading and releasing property. Polymeric nano particulate systems are available in wide variety and have established chemistry. Nontoxic, biodegradable and biocompatible polymers are available. Some nano particulate polymeric systems possess ability to cross blood brain barrier. They offer protection against chemical degradation. Smart polymers are responsive to atmospheric stimulus like change in temperature; pressure, pH etc. thus are extremely beneficial for targeted drug delivery. Some polymeric systems conjugated with antibodies/specific biomarkers help in detecting molecular targets specifically in cancers. Surface coating with thiolated PEG, Silica-PEG improves water solubility and photo stability. Surface modification of drug carriers e.g. attachment with PEG or dextran to the lipid bilayer increases their blood circulation time. Polymer drug conjugates such as Zoladex, Lupron Depot, On Caspar PEG intron are used in treatment of prostate cancer and lymphoblastic leukemia. Polymeric Drug Delivery systems are being utilized for controlled drug delivery assuring patient compliance.