Co-amorphous systems for the delivery of poorly water-soluble drugs: recent advances and an update.

Co-amorphous system, a homogeneous single-phase system containing two compatible drugs or a drug with a pharmaceutically acceptable small-molecule co-former, has been employed as a promising formulation technology to improve in vitro and in vivo performances of poorly water-soluble drugs such as solubility/dissolution, stability, mechanical properties and bioavailability. Furthermore, a deeper understanding of co-amorphous systems, including its detailed classification, the criteria of co-former selection, stability mechanisms and the faced challenges as well as perspectives, will be more conducive to its development and application.