Authors: R.C. Dutta, B. Rai
Affilation: Tata Research Development and Design Centre, India
Pages: 281 - 284
Keywords: hydrogels, cotrolled drug delivery, molecular dynamics, cross-linking density
Traditionally, a drug is administered initially at a higher dosage so as to repeat the next dose after several hours or days. This, besides being un-economical, results in side effects. Recently, there has been an increased attention on the methods of continuous administration of drugs in a controlled fashion. One of the promising methods of accomplishing this is to incorporate a drug in the polymer matrix. Cross-linked polymeric gels like hydrogels are currently being evaluated as carriers in controlled delivery system. The cross-linking density is an important parameter to engineer a given hydrogel. Experimental estimation of cross-linking density is expensive and time consuming. Several theoretical models have also been developed to model the diffusion of molecules in hydrogels. However, application of these theoretical relations is limited. Molecular dynamics (MD) simulations offer a paradigm to explore various phenomena occurring at pico/nanosecond time scales. MD simulations also possess an inherent advantage over continuum modeling in addressing nano-scale interactions between drug and polymer networks which are crucial for designing customized gels. In this paper we report on the effect of cross-linking ratio on diffusivity of drug molecules in polymeric hydrogels as studied through MD simulations.