Controlled release of lidocaine and diclofenac from chitosan particles

Abstract

Chitosan was used for controlled release of drug models, lidocaine and diclofenac. Chitosan/surfactant/polyanion particles were prepared with polyanion as the coacervation crosslink agent. The drug loaded chitosan particles were characterized for particle size, morphology, drug loading efficiency and in vitro release, which were found dependent on the factors of chitosan concentration, drug concentration and polyanion types. the particle size of chitosan/surfactant/polyanion particles were increased with the chitosan concentration in range of 10-30 micrometers. Two different methods were used for drug loading, incubation can loaded drug more than incorporation. The maximum loading efficiencies of drug were 80% for lidocaine and 70% for diclofenac, using incubation method. The loading efficiency was significantly decreased by the increase of initial drug concentration. In vitro release study at pH 7.4 showed a release profile consisting of an initial burst in the first 30 minutes and a continuous slow release for 8 hours for both drug models.