The present invention generally relates to foams and particles made from such foams, for applications such as drug delivery. The foams or particles may comprise a pharmaceutically acceptable polymeric carrier. In some cases, the foams may include colloidal particulates. A first aspect of the present invention is generally related to polymer-based foams or particles containing pharmaceutically active agents. In some cases, the foam or particle may contain smaller colloidal particulates therein. Such colloidal particulates may be used, for example, to limit the amount of material within certain regions of the foam, or exclude pharmaceutically active agents from being located within certain portions of the foam, which may useful for enhancing release of pharmaceutically active agents from the foam. In some cases, the colloidal particulates may cause the foam or particle to have an unexpectedly high specific surface area. The foam, in certain embodiments, can exhibit a relatively high loading of the pharmaceutically active agent. The foam may be microcellular in certain instances. The foam may also be created using a supercritical fluid, for example, supercritical C02. For instance, a precursor to the foam, containing a pharmaceutically active agent, a pharmaceutically acceptable polymeric carrier, and colloidal particulates, can be mixed with a foaming agent. The pressure may then be decreased, thereby causing the foaming agent to expand and causing a foam to form. The foam may also be ground or milled, or otherwise processed, to form particles such as nanoparticles.La présente invention concerne, de manière générale des mousses et des particules faites à partir de telles mousses, pour des applications telles que ladministration de médicaments. Les mousses ou particules peuvent comprendre un vecteur polymère pharmaceutiquement acceptable. Dans certains cas, les mousses peuvent comprendre des particules colloïdales. Un premier aspect de la présente invention se rapporte
