Hot melt extrusion and its pharmaceutical applications

The purpose of this article is to appraise the published scientific literature related to the technique of hot-melt extrusion and provide an insight en route for the operation and the process involved in this technology. This article reviews the advantages and limitations of the hot-melt extrusion process, equipment and materials used with a focus on the applications of this technique in relevance to the pharmaceutical industry. Hot-melt extrusion provides a continuous manufacturing process for moisture sensitive thermostable drugs. Extruders are of different types and twin screw extruder is the most widely used. Commonly used materials for hot-melt extrusion include polymeric carriers like ethyl cellulose, hydroxypropylcellulose, polyethylene glycol, polyethylene oxide, poly methacrylates and plasticizers like triethyl citrate, triacetin, propylene glycol, dibutyl sebacate, diethyl phthalate and glycerol monostearate. This technology offers an opportunity of earning immense intellectual property wealth as is evident from an increasing number of patents and publications using hot-melt extrusion since last few years in a variety of applications like sustained/ delayed release systems, films for transdermal or trans-mucosal drug delivery, solubility and bioavailability enhancement, taste masking and also for making amorphous materials. In near future, hot-melt extrusion would certainly emerge as an extremely preferred technology for various new chemical compounds in the pipeline.