2.4. Amorphous Solid DispersionsThe

2.4. Amorphous Solid DispersionsThe implementation of a solid dispersion as part of a dosage form is considered one of the mosteffective ways to improve the aqueous solubility of an API and consequently its bioavailability. A soliddispersion describes the dispersion of one or more active ingredient(s) in a carrier matrix material.The matrix consists of a polymer in most cases, and examples include PVP (polyvinyl pyrrolidone),HPMC (hydroxypropyl methylcellulose), HPMCP (hydroxypropyl methylcellulose phthalate), chitosan,CMC (carboxymethylcellulose), sodium alginate and sodium starch glycolate. A solid dispersionsystem contains potential energy that is available to assist in maximizing drug release. Upon reachinga specific area in the human gastro-intestinal tract that is favorable for drug dissolution and absorptiondue to certain favorable environmental properties, the maximum drug concentration will be releasedfrom the dispersion. Solid dispersions can be prepared using methods such as spray drying, freezedrying, co-precipitation, fusion methods, hot melt extrusion and supercritical fluid precipitation [34,35].