Nanoparticle-integrated film-forming sprays: formulation advances, mechanistic insights, and therapeutic applications

Nanoparticle (NP) integrated film-forming sprays (NP-FFS) epitomizes a novel advanced approach in the administration of topical and transdermal medications, addressing prevalent issues of conventional formulations like insufficient drug absorption, dosage variability, and poor patient compliance. These systems synergize the convenience and flexibility of FFS with the multifarious benefits of NPs, including enhanced bioavailability, targeted and sustained drug release, and improved drug stability. The film-forming matrix facilitates strong adherence and intimate contact to bio-membranes and ensures even drug distribution, while the added NPs allow for deeper skin penetration and a more controlled drug release. This review examines the mechanistic aspects, formulation advances in NP-FFS and outlines the contribution of their components, especially the inclusion of small NPs. Their versatility is reflected in their applications in treating infections, managing common wounds and skin conditions, and assisting in localised cancer treatments. This review is a critical assessment of the strategies of formulations, mechanistic phenomena of film formation and NP integration, approaches of analytical characterization, and ex-vivo and in-vivo studies pertaining to the delivery system. The particular attention is given to principles QbD in formulations design, therapeutic and translational issues that could impact clinical progress. The review discusses the challenges in such systems pertaining to formulation, including concerns pertaining to compatibility, long-term dermal safety evaluation, commercial manufacturing, and the lack of harmonized regulatory guidelines for topical nanomedicines.