The rate of drug release from polymer matrix-based sustained release formulations is often controlled by the thickness of a gel layer that forms upon contact with dissolution medium. The effect of formulation parameters on the kinetics of elementary rate processes that contribute to gel layer formation, such as water ingress, polymer swelling and erosion, is therefore of interest. In the present work, gel layer formation has been investigated by magnetic resonance imaging (MRI), which is a non-destructive method allowing direct visualization of effective water concentration inside the tablet and its surrounding. Using formulations with Levetiracetam as the active ingredient, HPMC as a hydrophilic matrix former and carnauba wax (CW) as a hydrophobic component in the matrix system, the effect of different ratios of these two ingredients on the kinetics of gel formation (MRI) and drug release (USP 4 like dissolution test) has been investigated and interpreted using a mathematical model.

Department of Chemical Engineering Institute of Chemical Technology Prague Technická 5 166 28 Prague 6 Czech Republic

Zentiva k s U Kabelovny 130 Prague 10 Czech Republic

References provided by Crossref.org

Investigation of Dissolution Mechanism and Release Kinetics of Poorly Water-Soluble Tadalafil from Amorphous Solid Dispersions Prepared by Various Methods

The Combined Use of Imaging Approaches to Assess Drug Release from Multicomponent Solid Dispersions