Interpenetrating polymer network blend microspheres of chitosan and hydroxyethyl cellulose for controlled release of isoniazid.

Glutaraldehyde crosslinked interpenetrating polymer network (IPN) blend microspheres of chitosan (CS) and hydroxyethyl cellulose (HEC) were prepared in the form of microspheres (66-82 microm dia) and investigated for the controlled release (CR) of isoniazid (INH), an antituberculosis drug. Microspheres were characterized by X-ray diffraction (XRD) to study the uniform distribution of drug in the matrices, differential scanning calorimetry (DSC) and thermogravimetry (TGA) to study thermal stabilities of IPN blends. Fourier transform infrared (FTIR) spectroscopy was used to understand chemical interactions and to assess the IPN structure. Scanning electron microscopy (SEM) was employed to investigate the morphology of microspheres. Drug-loaded microspheres were produced in spherical shapes with encapsulation efficiency ranging from 50 to 66%. Equilibrium swelling measured in pH 7.4 buffer solution as well as in vitro release of drug in pH 1.2 and 7.4 buffer solutions indicated the dependence of drug release on crosslinking as well as blend composition of the IPN matrix. Copyright 2010 Elsevier B.V. All rights reserved.