Hot-melt extrusion (HME) is an established process that has been used since the early 1930s, predominately in the plastics manufacturing …
Hot melt extrusion (HME) is the process of applying heat and pressure to melt a polymer and force it though an orifice in a continuous process. HME is a well known process, developed to produce polymer products of uni-form shape and density, and its industrial application dates back to the 1930’s. It is one of the most widely applied processing technologies in the plastic, rubber and food industries and is used to prepare more than half of all plas-tic products including bags, films, sheets, tubes, fibers, foams, and pipes.
HME has more recently been applied to the health-care in-dustry where it is used to manu – facture medical devices and to mix active pharmaceutical ingredients (APIs) with polymers to enhance the API’s bioavailability or prepare precursors for thermoplastic drug-eluting devices such as subcuta-neous and intraocular implants and intravaginal rings. This techni-cal brief discusses the equipment and principles of HME with a par-ticular emphasis on its use in the pharmaceutical industry.
HME is carried out using an ex-truder – a barrel containing one or two rotating screws that transport material down the barrel. Extrud-ers consist of four distinct parts:1. An opening though which ma-terial enters the barrel, that may have a hopper that is filled with the material(s) to be extruded, or that may be continuously supplied to in a controlled manner by one or more external feeder(s).2. A conveying section (process section), which comprises the bar-rel and the screw(s) that transport, and where applicable, mix the ma-terial,3. An orifice (die) for shaping the material as it leaves the extruder, 4. Downstream auxiliary equip-ment for cooling, cutting and/or collecting the finished product.
Post time: Feb-10-2020