title: Rheology as a tool for evaluation of melt processability of innovative dosage forms.
abstract: Future manufacturing of pharmaceuticals will involve innovative use of polymeric excipients. Hot melt extrusion (HME) is an already established manufacturing technique and several products based on HME are on the market. Additionally, processing based on, e.g., HME or three dimensional (3D) printing, will have an increasingly important role when designing products for flexible dosing, since dosage forms based on compacting of a given powder mixture do not enable manufacturing of optimal pharmaceutical products for personalized treatments. The melt processability of polymers and API-polymer mixtures is highly dependent on the rheological properties of these systems, and rheological measurements should be considered as a more central part of the material characterization tool box when selecting suitable candidates for melt processing by, e.g., HME or 3D printing. The polymer processing industry offers established platforms, methods, and models for rheological characterization, and they can often be readily applied in the field of pharmaceutical manufacturing. Thoroughly measured and calculated rheological parameters together with thermal and mechanical material data are needed for the process simulations which are also becoming increasingly important. The authors aim to give an overview to the basics of rheology and summarize examples of the studies where rheology has been utilized in setting up or evaluating extrusion processes. Furthermore, examples of different experimental set-ups available for rheological measurements are presented, discussing each of their typical application area, advantages and limitations.
authors: University of Copenhagen, Department of Pharmacy, Universitetsparken 2, 2100 Copenhagen, Denmark. Electronic address: johanna.aho@sund.ku.dk.
authors: Johanna
authors: J
authors: Aho
authors: University of Copenhagen, Department of Pharmacy, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors: Johan P
authors: JP
authors: Boetker
authors: University of Copenhagen, Department of Pharmacy, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors: Stefania
authors: S
authors: Baldursdottir
authors: University of Copenhagen, Department of Pharmacy, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors: Jukka
authors: J
authors: Rantanen
mesh_terms: D016503:Drug Delivery Systems / Q000295:instrumentation; D005079:Excipients / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D011108:Polymers / Q000737:chemistry*; D066330:Printing, Three-Dimensional / Q000295:instrumentation*; D012212:Rheology; D013678:Technology, Pharmaceutical / Q000295:instrumentation*
chemical_list: D005079:Excipients; D011108:Polymers
keywords: 3D printing; Hot melt extrusion; Polymers; Process design; Rheology; Rheometry