Challenges in the development of long acting injectable multivesicular liposomes (DepoFoam® technology).

Multivesicular liposomes (DepoFoam® technology) are distinctive lipid-based sustained release drug delivery systems. Their non-concentric structure differentiates them from unilamellar and multilamellar liposomes. Several products using DepoFoam® technology have been successfully developed and translated into clinical and commercial applications. The unique composition and structure of these particles result in large drug-trap volumes, diverse loading capacities, variable release rates, and different administration routes. With all these advantages, DepoFoam® based products can achieve sustained release pharmacokinetics and significantly improved half-life in various subject species. However, the complexity of constituents and the manufacturing process, as well as the complicated structure and release mechanism, pose challenges to the translation and application of DepoFoam® technology. This review aims to summarize current approved commercial products based on DepoFoam® technology, their structures and components, large-scale manufacturing processes, release characteristics, in vivo pharmacokinetics and clinical outcomes. Challenges in the development and approval of multivesicular liposomes are also highlighted. The persistent academic and industrial research will be needed to overcome the difficulties in developing this unique drug delivery system and pave the path for successful DepoFoam® applications in the future.