Polymers of biodegradable and biocompatible nature are widely used for sustained/controlled drug delivery of the drug. While the use of natural and synthetic polymers alone cannot be able to fulfill all the requirements of particular delivery system. Hence, natural polymers after suitable treatment are widely used in the pharmaceutical market just because of their lower cost, lesser toxicity, biodegradable and biocompatible property. The safety margin of the natural polymer is also high. But in comparison with synthetic polymers, the physicochemical properties of natural polymers are poor. So, combining the physical and chemical properties of two different polymers may provide a significant advantage in the drug delivery system and it can also be achieved by combining the synthetic and natural polymer. Such types of combinations are very helpful in sustaining the release of the drug (s) which has a short half-life.
Recently, the controlled drug delivery system is the most popular system of the drug delivery which minimize the risk of toxicity by maintaining the release of drug from its dosage form and target site specificity of the formulation. Interpenetrating polymer networks (IPNs) are also most popular and rising biomaterial for the novel drug delivery.
An IPN is a simple structure of two or more polymers in which they are combined partially with each other by a bonding between them. The bond is not too strong viz. the bonding between the polymers are not covalent. The bonds between polymers in IPNs can be easily broken when it come in contact with a solvent medium or chemical. The formation of IPN is happened by the combination of two polymers at a specific temperature so the phase separation is impossible at that condition at the normal temperature or it can be happened by the influence of another chemical or solvent. The properties of both the polymer used in IPN are combined and also can be provide a synergistic effect.