title: Hot-melt co-extrusion: requirements, challenges and opportunities for pharmaceutical applications.
abstract: OBJECTIVE
  Co-extrusion implies the simultaneous hot-melt extrusion of two or more materials through the same die, creating a multi-layered extrudate. It is an innovative continuous production technology that offers numerous advantages over traditional pharmaceutical processing techniques. This review provides an overview of the co-extrusion equipment, material requirements and medical and pharmaceutical applications.
  
  
  RESULTS
  The co-extrusion equipment needed for pharmaceutical production has been summarized. Because the geometrical design of the die dictates the shape of the final product, different die types have been discussed. As one of the major challenges at the moment is shaping the final product in a continuous way, an overview of downstream solutions for processing co-extrudates into drug products is provided. Layer adhesion, extrusion temperature and viscosity matching are pointed out as most important requirements for material selection. Examples of medical and pharmaceutical applications are presented and some recent findings considering the production of oral drug delivery systems have been summarized.
  
  
  CONCLUSIONS
  Co-extrusion provides great potential for the continuous production of fixed-dose combination products which are gaining importance in pharmaceutical industry. There are still some barriers to the implementation of co-extrusion in the pharmaceutical industry. The optimization of downstream processing remains a point of attention.
authors.affiliation: Laboratory of Pharmaceutical Technology, Ghent University, Ghent, Belgium; SEPS Pharma, Ghent, Belgium.
authors.forename: An-Katrien
authors.initials: AK
authors.lastname: Vynckier
authors.forename: Lien
authors.initials: L
authors.lastname: Dierickx
authors.forename: Jody
authors.initials: J
authors.lastname: Voorspoels
authors.forename: Yves
authors.initials: Y
authors.lastname: Gonnissen
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Remon
authors.forename: Chris
authors.initials: C
authors.lastname: Vervaet
mesh_terms: D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers / Q000737:chemistry; D004339:Drug Compounding / Q000295:instrumentation / Q000379:methods*; D005615:Freezing; D006358:Hot Temperature; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D011108:Polymers / Q000737:chemistry; D012996:Solutions
chemical_list: D004337:Drug Carriers; D004364:Pharmaceutical Preparations; D011108:Polymers; D012996:Solutions
keywords: co-extrusion; fixed-dose combination products; hot-melt extrusion; oral drug delivery systems; pharmaceutical applications