Coated Interpenetrating Blend Microparticles of Chitosan and Guar Gum for Controlled Release of Isoniazid

Abstract

This work reports on the novel development of IPN microparticles of chitosan (CS) and guar gum (GG) that are enteric coated with NaAlg and magnesium aluminum silicate (MAS) for controlled release of isoniazid. The matrices have been characterized by X-ray diffraction (XRD) to understand drug distribution, DSC for thermal stability, and Fourier transform infrared spectroscopy (FTIR) for investigating the chemical interactions of drug with the matrices. Surface morphology was investigated by scanning electron microscopy. These microparticles exhibited encapsulation efficiencies from 47 to 58%. Equilibrium swelling as well as in vitro release trends of the formulations studied in pH 1.2 and 7.4 buffer media showed the dependence of drug release on cross-linking, blend ratio of the matrix and coating, all of which affected the release time of drug from 1 to 4 h up to 50 h. The coated microparticles have reduced the burst release in gastric media to enhance in intestinal media.