Preparation and in vitro Release Mechanisms of Modified Pectin Matrix Tablets for Colon-Targeted Drug Delivery

Abstract

To deliver bioactive components to the colon, an oral, colon-targeted, microparticle delivery system was developed based on pectin. Pectin was modified by mechanical activation, resulting in controllable release properties, as well as dramatic decreases in solubility. Mechanically activated pectins (MAP) were characterized by Fourier transformed infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H-NMR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The FTIR and 1H-NMR analyses revealed that after mechanical activation, the hydrogen bonds between pectin molecules were broken, and intermolecular crosslinking was decreased. The DSC analysis indicated that the thermal stability of pectin was decreased by mechanical activation. The SEM revealed that MAP particles were smaller, more uniform, and had smoother surfaces than unmodified pectin. An in vitro release assay and the study of drug release kinetics demonstrated that bovine serum albumin (BSA) release from MAP-containing matrix tablets was controllable. The results demonstrated that at a suitable pectin content and hydrophobicity level, matrix tablets prepared with MAP can exhibit good colon-targeted drug release.

Keywords

• Pectin; Matrix tablet; Colon; Mechanical activation; Releasing property