Establishment of a Molding Procedure to Facilitate Formulation Development for Co-extrudates

Simone Eder, Michela Beretta, Andreas Witschnigg, Ioannis Koutsamanis, Karin Eggenreich, Johannes G. Khinast, Gerold Koscher, Amrit Paudel, Klaus Nickisch, Maika Friedrich, Eleonore Froehlich, Eva Roblegg*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Co-extrusion offers a number of advantages over conventional manufacturing techniques. However, the setup of a co-extrusion line is cost- and time-intense and formulation development is challenging. This work introduces a novel procedure to test the applicability of a co-extruded reservoir-type system at an early product development stage. We propose vacuum compression molding (VCM), a fast procedure that requires only small material amounts, for the manufacturing of cylindrical reservoir-type system. To this end, the commercially available co-extruded product NuvaRing® and variations thereof were used as test systems. All VCM systems showed a homogeneous skin thickness that adhered well to the core, thereby providing a precise core/skin interface. As drug release is a key criterion for pharmaceutical products, a modified in vitro dissolution method was set up to test the VCM systems. The drug release from the VCM systems was in the same order of magnitude as the corresponding co-extruded strands and followed the same release kinetics. Moreover, the VCM systems were capable of indicating the relative effect of formulation-related modifications on drug release. Overall, this shows that this system is a powerful tool that facilitates formulation tailoring and co-extrusion process setup at the earliest stage.

Original languageEnglish
Pages (from-to)2971-2976
Number of pages6
JournalAAPS PharmSciTech
Issue number8
Publication statusPublished - 1 Nov 2017


  • co-extrusion
  • in vitro dissolution
  • reservoir system

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Pharmaceutical Science
  • Drug Discovery


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