Polymers as Formulation Excipients for Hot-Melt Extrusion Processing of Pharmaceuticals

Department of Pharmaceutical Technology, Faculty of Pharmacy, School of Health Sciences, 

Hot Melt Extrusion (HME) is a continuous solvent- and dust-free manufacturing process that requires the use of only a limited number of excipients and low-cost instrumentation. The purpose of HME is to create a dispersion of the Active Pharmaceutical Ingredient (API) in a polymer matrix in order to achieve solubility enhancement, release rate modulation, taste masking, or to develop a new dosage form. However, polymers must fulfill a number of requirements in order to be suitable for HME processing. 

Therefore, in the following chapter, polymers, polymer blends, and novel self-pleisticized block copolymers commonly used for HME are presented. The requirements of thermoplastic polymeric excipients for successful HME processing, theoretical and empiriccd methods to predict polymer-API miscibility, as well as the factors determining the nature and properties of the resultant solid dispersion are discussed with an extensive review of case studies from recent relevant Hterature. 

Keywords Hot-melt extrusion, thermoplastic polymers, drug-polymer miscibility, polymer matrix, polymeric excipients, sohd dispersions, solid solutions 

One of the numerous applications of polymers as formulation excipients in the pharmaceutical industry is their use as matrix formers in the hot-melt extrusion process. Although HME was invented at the end of the 18th century as a method of manufacturing metal parts, its potential for the production and treatment of polymers was recognized and has now become the main production method of plastic materials [1]. However, HME was only recently introduced in the pharmaceutical industry [2], but since its introduction it has opened a new area of industrial application for polymers in pharmaceutical formulation. 

---

Polymers as Formulation Excipients for Hot-Melt Extrusion Processing of Pharmaceuticals... 

---