A dynamic duo comes of age: Nanocrystals and microneedles for hydrophobic drug delivery.

Introduction: Nanocrystals (NCs) combined with microneedles (MNs) represent an emerging drug delivery platform with significant potential to overcome challenges in the administration of poorly-water soluble drugs. This next generation delivery approach increases the surface area and dissolution rate of drugs via the production of NCs, overcoming the skin barrier in a minimally invasive manner, afforded by the MN technology.

Areas covered: This focused review summarizes the research from the past eight years on the development of NC-loaded MN systems. It discusses the formulation strategies, characterization, and therapeutic benefits reported in the literature, highlighting controlled dissolution and sustained release capabilities. The review also addresses critical challenges related to clinical translation, such as validation of therapeutic efficacy and broadening clinical applications.

Expert opinion: NC - MN systems have shown promise in self-administered and long-acting therapies. Yet, stability issues, manufacturing reproducibility, and regulatory uncertainty still remain barriers to translation. Progress in scalable manufacturing and regulatory engagement is encouraging, but robust in vivo data and standardized characterization are needed. Continued interdisciplinary work and collaboration across academia, industry, and regulatory agencies will be vital to realize the clinical potential of this platform.