Polymer grafting and applications in pharmaceutical drug delivery systems - a brief review

Abstract

Selection of proper polymer system is a critical step involved in the formulation of dosage form. Type of polymer/s incorporated in pharmaceutical formulation majorly decides the stability of formulation and drug itself, mechanism, and rate of drug release. Pharmaceutical and biological therapeutics are suffered from disadvantages such as short half-lives, poor bioavailability, and physical and chemical instability. Delivery of drugs to target site at a specific concentration for a specific time can be successfully achieved by the use of suitable polymer/s. Thus, it is not necessary that available polymer till the date should have all ideal properties with respect to above. This makes a demand of tailored polymers with desired features and introduces concept of grafting for making new polymers to be used in dosage forms. Grafting can be achieved by various techniques described herein and can be analyzed by various modern analytical techniques including infrared, NMR, X-ray diffractometer, and differential scanning calorimeter. These grafted polymers offer many applications in terms of site drug/biological carrying capacity, tailored physicochemical properties based dosage form modifications and with desired features, and also to deliver therapeutics at specific sites. Considering these advantages, a number of applications of grafted polymers developed and many patents were filed in this area till the date. This review highlights the basic concept of grafting and its various techniques and their significant pharmaceutical applications.