Establishing Design Space for Tramadol HCl Release from Hydrophilic Matrix Tablets

Abstract

The aim of this study was establishing design space for robust formulation of hydrophilic extended release matrix tablets with tramadol hydrochloride as highly soluble, high dose drug. In the first part of the study, linear relationship between slope of Higuchi's model (K-h) and tablet surface/tablet volume (SA/V) ratio was confirmed varying drug loading in the range between 27.78 and 55.56% (w/w). Established relationship was tested in the second part of the study using different tablet shapes and sizes. Compression force was varied between 160 MPa and 300 MPa as critical process parameter, while drug loading and polymer concentration were recognized as critical input material attributes. High correlation was established between experimentally observed drug release profiles and drug release profiles predicted using K-h-SA/V relationship. Design space was established, where drug release could be accurately predicted for any drug loading/polymer content/compression force in the investigated range.