Extrusion

Using hot melt extrusion, we have both the facilities and expertise to develop tailor made controlled-release delivery systems such as vaginal rings and implants.

Hot melt extrusion is the process of melting a polymer at elevated temperatures and forcing it through a die in order to produce a strand with a fixed cross-sectional profile in a continuous manner. Over the past decades hot melt extrusion has emerged as a suitable technology for the production of pharmaceutical drug delivery systems such as vaginal rings, implants and transdermal films.

In principle there are two types of extruders: blend and single screw extruders.

Blend extruders have two screws that exhibit both mixing and conveying sections. The main purpose of the blend extruder is to produce a homogeneous strand of drug and polymer. Depending on the design of the delivery system, this can either be a solid dispersion of drug particles, or a solid solution of a drug in a polymer. After the blend extrusion, the strands are cut into pellets using a strand granulator.

The main purpose of a single screw extruder is to melt the pellets again and to produce a medicated fiber with a uniform diameter. By applying more than one extruder, it is possible to produce coaxial fibers that consist of multiple layers that contain one or more drugs. By varying the thickness of the layer, the polymer type and the concentration of drug, a controlled delivery system can be designed that is capable of delivering one or more drugs at a desired rate and time.