Green processes in drug delivery systems

The release rate of a therapeutic agent from a drug delivery system can be manipulated by altering the dissolution rate of the drug material as well as adjusting the cross linking density between the polymers entrapping it. The present study investigates these two parameters employing environmentally benign concepts. First, the dissolution of terephthalamide crystals and hydroquinone-terephthalamide cocrystals were monitored using a particle size analyzer. The ability to control the dissolution rate of hydroquinone using crystal engineering was demonstrated. The factors determining the crystal dissolution rate are discussed. Second, the crosslinking density of drug entrapment polymers, such as polyethylene glycol (PEG) and polyvinyl alcohol (PVA) was controlled via photo-activated crosslinking using a novel epoxy thymine crosslinking agent. The effect of the crosslinking density on the mechanical properties of the polymer was achieved by either varying the UV-irradiation time or changing the ratio of crosslinking agent in the polymer system.