RADIATION FORMATION OF HYDROGELS FOR DRUG-DELIVERY

Using N-vinylpyrrolidone as polymer of choice, it has been pointed out that radiation formation of hydrogels in aqueous solutions proceeds according to the radical mechanism. Both in the processes of polymerization and crosslinking, the main role is played by indirect effect, i.e., these processes are initiated by intermediate products of radiolysis of water. In the presence of oxygen in the irradiated solutions, the process of gel formation is accompanied by the reactions leading to the scission of polymer main chain. Analysing the course of gel formation the use of modified Charlesby equation was suggested. This equation has an universal character. In order to calculate the values of the yield of radiation crosslinking a new method was used. It allows to obtain results without previous determination of the molecular weights of polymer to be crosslinked.