(638c) Injection Moulding As a One-Stop-Production to Produce Pharmaceutical Dosage Forms

Dissolving or dispersing of Active Pharmaceutical Ingredients (APIs) in a molten polymer matrix is a promising method to increase the water solubility of poorly water soluble drugs. The enhanced solubility is achieved by forming various types of solid dispersion. One technology to establish such systems is the Hot Melt Extrusion (HME). Another promising technology which combines the advantages of HME with a direct shaping process is the injection moulding (IM). Thereby the materials are molten by a single screw extruder and fed into an antechamber of the screw. In the next step, the screw stops and acts as a piston applying high pressure on the material and injects it into a mould. The mould consists of different numbers of cavities with the final geometry of the product, e.g. tablets. By defining a specific shape of the cavitie(s), a broad range of geometries can be established. Beside the extrusion, injection moulding is the state-of-the-art technology in the plastic industry. Also in the production of medical devices the IM has a wide field of use. 

In our project the focus of investigation is on both the possibilities but also the limitations of IM when used for the production of pharmaceutical dosage forms. The trials were conducted on an E-Mac 50 (Engel, Austria), a small production machine. The experiments followed two different production routes. In the first route, the input materials were pellets made of different polymers (PVCL-PVAc-PEG) and an API in different ratios. They were produced in a prior HME step using a ZSK 18 Twin Screw Extruder (Coperion, Germany). In the second production route, a premix consisting of the API and the polymer was fed directly into the plastification unit of the injection moulding machine. The goal of this route is to establish a one stop production where the raw material is converted into the final product within one production step showing process periods of 2 to 3 minutes.

The obtained tablets were characterized extensively. Product parameters like release behaviour, thermogravimetric behaviour, content uniformity, level of impurities and degradation products, but also physical properties like hardness and friability or the identification of type of solid dispersion were in focus of our investigation.

References:

1. Zema L, et.al.: Injection Molding and its application to drug delivery, J. Control. Release 2012.
2. Quinten T, et.al.: Evaluation of injection moulding as a pharmaceutical technology to produce matrix tablets, European Journal of Pharmaceutics and Biopharmaceutics 71 2009 145–154
3. Breitenbach J.: Melt extrusion: from process to drug delivery technology, European Journal of Pharmaceutics and Biopharmaceutics 2002, 54, 107-117.