Chemical sterilization with ethylene oxide gas offers the advantage of effective treatment at ambient temperature and is useful for hydrolytically unstable polymers. Nevertheless, its popularity is decreasing due to the well-known toxicity

and flammability of ethylene oxide. High-energy radiation sterilization method has the advantage of high efficiency, negligible thermal effects. Polymers exhibiting high heats of polymerization tend to cross-link upon radiation, indicating an apparent increase in mechanical stability with increasing radiation doses [39, 40]. Radiation cross-linking does not involve the use of chemical Inhibitors,research,lifescience,medical additives and therefore retaining the biocompatibility of the biopolymer. Also, the modification and sterilization Inhibitors,research,lifescience,medical can be achieved in a single step and hence it is a cost-effective

process to modify biopolymers having their end use specifically in biomedical application. 5.3. Large Scale Production The major challenge of research and development of IPNs for drug delivery is large scale production. There is always a need to scale up laboratory or pilot technologies for eventual commercialization. Inhibitors,research,lifescience,medical It is easier to modify IPNs at laboratory scale for improved performance than at large scale. Maintaining concentration and composition of polymers at large scale is also a challenge. Despite the number of researches and patents for IPN drug delivery technologies, commercialization is still at its early Inhibitors,research,lifescience,medical stage. This is partially due to the fact that most of the research studies are carried out by researchers in academia. Nevertheless, greater effort is needed to bring IPN based drug delivery systems from the experimental level to the pilot scale production and extend their practical applications. This can be achieved by addressing several aspects, which include boosting the selectivity without compromising biocompatibility and stability, optimizing Inhibitors,research,lifescience,medical polymer modification techniques, using the proper

engineering configurations, understanding the mechanism of transport, and using cost-effective materials and methods. 6. Preclinical Studies with IPNs A preclinical study is a stage of research that the IWP-2 begins before clinical trials (testing in humans) and during which important feasibility, iterative testing, and drug safety data is collected. The main goals of preclinical studies are to determine a product’s ultimate safety profile. IPNs based on poly(acrylic acid) and gelatin were evaluated for in vivo biodegradation and release of gentamicin sulphate by Changez et al. [41] In vivo degradation studies demonstrated that the degradation and drug release depend on the composition of hydrogels. It was observed that the rate of in vivo degradation of hydrogels was much lower than in vitro degradation.