Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

Abstract

The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for theophylline as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks.

Novi kopolimerni hidrogelovi na bazi 2-hidroksietil metakrilata (HEMA) i itakonske kiseline (IK) su dobijeni gama ozračivanjem, u cilju ispitivanja njihove potencijalne primene u sistemima za kontrolisano otpuštanje aktivnih materija. Ispitan je uticaj sadržaja IK u P(HEMA/IK) hidrogelovima na bubrenje i sposobnost otpuštanja aktivnih materija, kao i uticaj različitih lekova - teofilina (TF) i fenetilin hidrohlorida (FE) na profil otpuštanja iz P(HEMA/IK) gelova, u in vitro uslovima. Difuzioni eksponenti bubrenja i otpuštanja lekovitih supstanci pokazuju da se mehanizmi upijanja pufera, kao i otpuštanja lekovitih supstanci mogu opisati Fikovim zakonom difuzije. Prema tome, kinetika bubrenja i brzina otpuštanja zavise od stepena bubrenja gelova. Kopolimerni hidrogelovi sa većim sadržajem itakonske kiseline brže otpuštaju lekove. Teofilin se brže otpušta iz gelova u odnosu na fenetilin hidrohlorid, jer je u pitanju molekul manje molske mase, kao i postojanje slabijih interakcija molekula TF sa P(HEMA/IK) kopolimerima.