Microspheres of Gelatin and Poly(ethylene glycol) Coated with Ethyl Cellulose for Controlled Release of Metronidazole

Abstract

A novel type of metronidazole (MN) loaded ethyl cellulose (EC) coated blend microspheres of gelatin (GE) with poly(ethylene glycol) (PEG) were prepared by the water-in-oil (w/o) emulsion method and cross-linked with glutaraldehyde (GA) to achieve an encapsulation efficiency of 68%. The microspheres were characterized by Fourier transform infrared spectroscopy (FTIR) to understand the chemical interactions between the drug and the polymer matrix. Differential scanning calorimetry (DSC) was used to investigate the molecular level drug dispersion into the polymer matrix as well as surface coating onto the microspheres, while scanning electron microscopy (SEM) was employed to investigate the surface morphology. The diffusion coefficient, Dv, and solvent front velocity, u, based on volume expansion of the microspheres were calculated from the dynamic swelling data of the matrixes to obtain insights into the transport phenomenon that showed a non-Fickian trend. In vitro release of MN was dependent on the extent...