Influence of polymer ratio and surfactants on controlled drug release from cellulosic microsponges.

Microsponge refers to a highly cross-linked particle system with a capacity to adsorb (like a dry sponge) pharmaceutical materials. There are various methods available to prepare microsponge formulations, in this study we used quasi emulsion-solvent diffusion method with a combination of hydrophobic (ethyl cellulose) and hydrophilic (hydroxypropyl methylcellulose) polymers mediated via Tween 80 and polyvinyl alcohol. Various ratios and amounts of the polymers and surfactants were used to prepare microsponge formulations using ketoprofen as a model drug and extensively characterised. Our results, for the first time, indicate successful and optimised formulation with desired pharmaceutical characteristics using a combination of hydrophobic and hydrophilic polymers.