POLYMERS : USED IN DRUG DELIVERY SYSTEMS

Abstract

Now -a -days Polymers have extended use in the formulation of tablets and capsules. These are also used in targeted drug delivery systems. These are advantageous in drug targeting by prolonging drug release time. By targeting Pharmaceutical drugs using different polymers makes possible to guarantee local or systemic drug delivery to the site. Mostly, polymers are strongly hydrophilic in nature leading to premature drug release. To overcome this problem some polysaccharides, such as inulin, guar gum, pectin have been chemically modified to increase their hydrophobicity. These polymers play an important role in targeting the drugs to their specific site and used in tablets and capsules. The drug is released by losing strength and tensility of polymers when acted by different polysaccharides. Different microcapsules are also prepared by using selected polymers of cellulose, such as cellulose acetate, cellulose acetate phthalate and hydroxypropyl methylcellulose phthalate. The influence, of different drug, polymer ratios and combination of polymers, on particle size, yield, and release kinetics is imperative. Cellulose acetate is a non-toxic cellulose polymer and it is insoluble in acidic and alkaline fluids and having superior film forming properties. It is extensively used as a coating material and matrix binder for tablets and capsules. It has threshold pH of 6 and expected to use as a carrier in the colonic drug delivery of drugs.