5.SMART CONTROLLED RELEASE POLYMERS AS BACKBONE OF PHARMACEUTICAL DRUG DELIVERY SYSTEM: OLD WINE INTO NEW BOTTLE WITH CHALLENGES AND PROMISES
This review addressed the role of polymer in efficient delivery of active pharmaceutical ingredients. Polymers are the strength of pharmaceutical drug delivery system by controlling the release rate and solving the troubles related with API such as solubility, bioavailability and stability. Polymers play vital role in drug delivery of immediate release dosage form (tablet, capsule) and modified release dosage form (gastro retentive dosage form). Biodegradable polymers pay more attention in drug delivery because of their biocompatible, biodegradable and non-toxic character additionally it show constant release rate of drugs. Now-a-days, synthetic biodegradable polymers are preferred more because they solve the trouble regarding with natural polymer such as lot to lot variation, microbial contamination and uncontrolled rate of hydration. Smart polymers show change in response with altered environmental conditions such as pressure, pH, temperature, change in concentration and ionic strength. In this review, we have included various aspects of polymers and discussed drug release mechanism such as degradation, diffusion and swelling. The recent advances in polymeric drug delivery system include molecularly imprinted polymer (MIPs) also discussed. In addition, this review also include role of various synthetic and natural plant derived biodegradable polymers functional in drug delivery.