Abstract
Although nanoparticles (NPs) show tremendous potential in the laboratory, most of them fail to reach clinical applications, highlighting a significant "translational gap" in nanomedicine. This gap is often due to a lack of focus on advanced formulation strategies required to transform NPs into functional drug products. Therefore, this review systematically addresses the crucial role of secondary delivery systems in bridging this gap. We analyze and compare various advanced formulation platforms, such as sterile injectables for the intravenous route, hydrogels for topical delivery, microspheres for the oral route, dry powder formulations for inhalation, and polymer implants for controlled release, and discuss how each system addresses specific clinical challenges related to route of administration, stability, and bioavailability. We conclude that shifting the focus from nanoparticle design alone to integrated formulation strategies is a fundamental step towards accelerating the translation of nanomedicines from the laboratory to the patient.