Improving the solubility of poorly water-soluble drugs is of crucial importance for developing and successfully commercializing new drug compounds. Combinatorial chemistry and high-throughput screening methods in drug discovery has increased the number and diversity of molecules of potential interest in drug development. That larger pool of candidates, although potentially beneficial, also creates challenges, namely more compounds of poor solubility. According to some industry estimates, approximately 70% of new chemical entities under development may be classified as BCS Class II compounds (i.e., high permeability and low solubility) (1). An upcoming webcast by Pharmaceutical Technology examines one technology to address low bioavailability: pharmaceutical melt extrusion.
In hot-melt extrusion, an amorphous solid solution of the crystalline drug substance is formed under shear and heat. Solubility parameters, combined with other physiochemical characteristics of the drug and excipients, can by used as predictive indicators in selecting initial formulation components. Successfully implementing pharmaceutical hot-melt extrusion dosage product development, however, requires not only careful selection of the active and inactive ingredients, but also of the appropriate processing conditions. Inadequate processing conditions can lead to thermal degradation of polymers, drug, or other formulation components. Melt-extrusion processing temperature, screw speeds, feed rates, and screw design play a crucial role in implementing the technology.
Producing a desired dosage form requires the optimization of both the formulation-development and manufacturing processes. The upcoming webcast, “Pharmaceutical Melt Extrusion Process Development,” examines how initial process parameters can be selected and optimized for a product produced using hot-melt extrusion. The webcast includes speakers from Roche, American Leistritiz, and Evonik, and will be broadcast on Oct. 4. Details may be found here at the PharmTech website.
1. P. Van Arnum, “Solubilizing the Insoluble,” Pharm. Technol. 34 (11), 50–56 (2011).