Description

Polymers are macromolecules formed by the combination of many repeated subunits such as monomers and smaller molecules. The word “polymer” has obtained from a Greek word “poly” and “mer,” which mean “many parts.” Polymers are one of the most useful versatile materials and have been used in day-to-day lives. Though, the biomedical relevance of polymers was made only from last 3 decades. The combination of polymer with pharmaceutical sciences led to a strong quantum bond formation in requisites of design and formulation of novel drug delivery systems (NDDSs). The natural polymers are mainly concerned in the field of pharmaceutical sciences because of their low cost, flexibility, low toxicity, renewability, biodegradability and can be easily modified. The naturally obtained polymers are commonly regarded as safe and found to be useful for oral consumption in pharmaceutical and food industries. The natural polymers are biogenic in nature and their biological characteristics and resemblance to the extracellular fluid matrix make them suitable for the drug delivery system. Moreover, the presence of chemically reactive sites on the natural polymers leads to addition of new functional groups to adjust the physical and chemical properties and thus endowing the formation of new material with remarkable functions. Additionally, various types of natural polymeric materials also could be incorporated with other synthesized or pure materials to make new hybrid materials.

The natural polymers have various applications and significance in drug delivery like controlled release, emulsification, solubilization, suspension, bioadhesion, thickening, gelling, viscosity enhancer, mechanical strengthening and encapsulation etc. The natural polymers are more preferred as compared to synthetic polymers because of many advantages.

Apart from numerous advantages there are some disadvantages of natural polymers that need to be overcome. These include batch to batch variation, microbial contamination, uncontrolled rate of hydration, slow process, heavy metal contamination and limited ability to tailor for specific properties.