Crosslinked poly(ethylene oxide) for drug release systems

摘要

AbstractThree types of poly(ethylene oxide) (PEO)‐ based hydrogels have been synthesized and studied for drug release applications: γ‐irradiated high molecular weight PEO, biodegradable polyether‐polyester networks with malic acid as crosslinker of poly(ethylene glycol)s and amphiphilic PEO‐based polyureas crosslinked with multifunctional isocyanates. Varying the length of the PEO chain and the type of the crosslinker, hydrogels with different swelling properties, loading capacities and release characteristics were obtained. A large number of pharmaceuticals(acebutolol. HCl, diclofenac. Na, procaine. HCl, phenobarbital.a, propranolol, etc.) were tested for a sustained release in different media (pH=1.2, 6.5, 7.4). Most of them # gave reasonable retarded release profiles for 8 hours when incorporated before the γ‐irradiation crosslinking of PEO. While amphiphilic hydrogels were found to be suitable for hydrophobic solutes, the biodegradable PEO‐based polyester ones affected predominantly the release of water‐soluble drugs. No pH effect was found for the γ‐irradiated PEO as a carrier in contrast to the strong pH dependence for the degradable