Comparison Drug Release from Simple and Layered Matrix Systems Containing Hydroxypropyl Methylcellulose

Abstract

Objective: The aim of this investigation was to compare the release behavior of propranolol HCl from simple matrix and layeredtablets containing HPMC and phytowax as matrix component using direct compression technique.Method: The test of drug release was performed in distilled water during 26 hrs using a dissolution apparatus and thereafter thedissolution profile fitting to different mathematical equations was carried out using least square fitting with a nonlinear computerprogram, Scientist for Windows, version 2.1.Results: Covering both planar surfaces of drug-loaded middle layer was able to attain a more sustainable drug release than asimple matrix which composed the same amount of matrix component. Additionally, the near-zero order release could beobtained for the first system whereas the drug release from simple matrix tablet was diffusion-controlled. As the number oramount of coating layer, and amount of matrix component in middle layer were increased, the drug release was noticeablyprolonged. Drug release from layered tablets was influenced by hydrodynamic force and incorporated diluents.Conclusion: Effective near-zero order controlled release of hydrophilic drug was obtained from three-layered matrix tabletscomprising HPMC as main matrix component. Modulation of drug release could be conducted by addition or increasing amountof water soluble substances into the matrix component of three-layered tablets.Key words: drug release, comparison, simple layered-matrix, layered-matrix, hydroxypropyl methylcelluloseThai Pharm Health Sci J 2008;3(2):219-228§