screw profiles before scaling-up to larger extruders for commercial production. In some cases, pharma compounders can use multiple mid-size extruders to run their larger volume, commercial applications, thus eliminating any changes that might result from scale up, notes Martin.
Upstream and
downstream handling APIs are typically powders, but in addition to appropri- ate powder handling equipment, some APIs are
toxic or highly potent and must be handled under containment to avoid harming operators. Some
formulations are pre-mixed, while others, particularly when using powdered API and a pelletized
polymeric excipient, must be split-fed.
Coperion’s 18-mm ZSK has improved barrel heating and cooling for extra precision when developing pharmaceutical products
Since pharma applications, especially at the pilot or laboratory scale, often run at lower rates than typical plastics applications, feeders that can accurately dose at low rates must be used. Other requirements include cleanability and GMP certification. Downstream, compounds are often pelletized, although the method must be compatible with the formulation. Bioresorbable polymers, for example, must be cooled with dry air because they begin to degrade in the presence of moisture, notes Foster Delivery Science’s Listro. Pelletizers for micro-pellets
of less than 1 mm are under development. Direct extrusion, which eliminates a heat-history for heat-sensitive APIs, is also used in the industry and is another area of development. Direct extrusion applica- tions include films for drug-eluting patches, rods for implantable drug delivery, or profiles for a variety of devices. While development cycles in the medical industry are
much longer than those of typical consumer or industrial plastics applications, we should continue to see new, innovative products in the coming years as plastics industry experts apply their knowledge and skills to medical markets.
1. J.DiNunzio, C. Martin, and F. Zhang, “Melt Extrusion: Shaping Drug Delivery in the 21st Century,” Pharm.Tech. supplement on Drug Delivery (Nov. 2010).
2. P. Van Arnum and R. Whitworth, “Continuous Progress in Continuous Manufacturing,” Pharm.T
ech. 35 (9), 44-47 (2011).
Maag Group is the innovative solution provider for pump, pelletizing and filtration systems. We deliver high-quality components and complete systems, from extruder tips to pelletizers. In addition to our primary locations in Switzerland and Germany, we have eight sales and service offices around the globe to provide our customers with full service par excellence.
Frankfurt, Germany June 18-22, 2012 hall 8, booth C38 hall 5, booth C33