Design and pharmaceutical applications of porous particles

Porous particles (PPs) are a novel kind of carrier with a large surface area, high porosity, stable uniform porous structure, tunable pore sizes with narrow distribution, and well defined surface properties. There are many methods for preparing PPs, mainly including using porogens or templating agents to form pores, self-forming pores by particle matrices without any pore-forming agents, and chemical synthesis. In this review, reports on various PPs are collected, which are applied in various fields of medicine for many purposes, such as improvement of dissolution of poorly soluble drugs, development of novel drug delivery systems, and improvement of the functional properties of drug-loaded particles. In general, these functions of PPs are closely related to their fundamental particle and pore properties, such as morphology, size, surface property, surface area, and porosity. The reasonable application of PPs has markedly facilitated the development of pharmaceutics and the number of published reports has increased progressively from year to year. However, there remains a serious deficiency of summarization and systematic analysis of these reports. Therefore, this review aims to provide a comprehensive and relevant overview on the design and pharmaceutical applications of PPs, which can serve as an informative reference for interested readers.