Influence of structural variations on drug release from lipid/polyethylene glycol matrices

Different combinations of monoacid triglycerides and polyethylene glycol powders of different molecular weights were successfully extruded below their melting temperatures as a basis for oral dosage forms. The incorporated polyethylene glycols exhibiting different mean molecular weights were compared with respect to their effect on the dissolution rate for a model drug, and a mean molecular weight of 10,000 resulted in the most advantageous characteristics (fastest dissolution). Triglycerides with different fatty acid chain lengths provided additional options for the extrusion temperature which is beneficial for temperature sensitive active pharmaceutical ingredients. To obtain stable extrudates with desirable and reproducible dissolution characteristics a good understanding of the underlying processes during processing and storage is mandatory.