Swelling, Dissolution and Disintegration of HPMC in Aqueous Media

Abstract

This paper contains the work on monitoring the swelling, dissolution, and disintegration processes for hydroxypropyl methylcellulose (HPMC) tablets fabricated under 400, 1000, 2000 kg/cm2 pressures. The density and porosity of tablets of three grades of HPMC (6, 40, 4000 mPa.s viscosity of 2 wt% aqueous solution at room temperature) were measured to identify the effect of different physical/chemical properties on the swelling and the subsequent processes involved. The process observations were conducted at human body temperature of 37°C to understand drug release. The cumulative swelling curve showed that particle size and their distribution in HPMC powder, and density and porosity of the formed tablets have influence on the swelling kinetics. The strength and thickness the gelated layer formed during the swelling process influenced by the chemical structure of HPMC ultimately determined the behavior during the swelling, dissolution and disintegration of the HPMC tablets. The possible mechanism leading to these changes was proposed. The detailed kinetic simulation of the integrated process was also discussed, which seemed to follow power-law formulations.