Originally developed by the plastics industry, HME technology is becoming a new drug delivery technology, which combines processing technology with pharmaceutical research creatively. This technique can be used to treat polymer materials above the glass transition temperature to promote the effective mixing of thermoplastic adhesives and/or polymers and active ingredients at the molecular level.
Hot melt extrusion technology combines many advantages of solid dispersion technology and mechanical preparation, realizes the reduction of dust, continuous operation, good reproducibility, high production efficiency and on-line monitoring. HME can not only promote the dissolution of soluble active ingredients and improve their bioavailability, but also be used to prepare sustained-release preparations. In addition, HME can also be used to prepare masked pellets or other special forms of preparations, such as film agents, rods and hollow cylindrical formulations.
Hydrolysis is not easy to occur because of the short duration of the extrusion process and the need for water or organic solvents, and the need for heating and drying.
The principle of hot melt extrusion technology
The equipment of HME technology is melt extruder, which can be divided into plunger type and screw type. The plunger type is gradually eliminated because of its weak mixing ability. Screw extruder is divided into single screw, twin screw and multi-screw extruder. At present, the first two kinds of extruder are most used in the field of preparation. Single twin screw extruder is composed of feeding system, transmission system, screw barrel system, heating and cooling system, die system, monitoring system and downstream auxiliary processing system.
