A successful formulation for oral administration of drugs with low solubility is solid dispersion. This type of formulation, which consists of a drug dispersed within a polymer matrix, can significantly increase the bioavailability of drugs by increasing their solubility. Solid dispersions are manufactured using one of two methods. In the first method, both the polymer and the drug are heated until they reach their melting points. Then, the melt is passed through an extruder (single-screw or twin-screw) to create a solid dispersion. The second method involves dissolving the polymer and the drug together in a mutual solvent, then spray drying the solution to create a solid dispersion.
These dispersion processes shrink the size of the drug and distribute drug particles throughout a water-soluble polymer matrix. That way, the overall formulation can dissolve within the body and the drug can be utilized more effectively. Polymers that can be used in solid dispersion formulations include cellulose derivatives, PVP, PEG, HPMC, HEMA, and poly-(meth)acrylates, among others.
There are currently several solid dispersion formulations of drugs available on the market. These formulations include Sporanox®, Intelence®, Prograf®, Crestor®, Gris-PEG®, Cesamet®, and Solufen®. Each of these products uses a different drug, which shows how versatile the solid dispersion formulation methods are.
The highly trained scientists at Phosphorex have extensive experience in creating solid dispersions. The technical support team is happy to help you choose if solid dispersion is the best formulation for your low solubility drug. Please feel free to contact us with any questions or to discuss your project.