Microneedle-mediated administration of drug nanocrystals

This chapter explores the combination of nanocrystals (NCs) andNanocrystals microneedles (MNs) as a versatile and promising strategy for drug delivery. Initially developed to enhance percutaneous administration, MNs have evolved into diverse formats—solid, coated, dissolving, hollow, and hydrogel-forming, each with distinct advantages depending on therapeutic goals. The combination of MNs with NCs offers a powerful platform to improve the delivery of poorly water-soluble drugs by enhancing dissolution rates while bypassing conventional administration barriers. This chapter outlines key MN fabrication techniques and discusses the rationale behind NC-loaded MNs. The common characterization methods used to evaluate drug loading, morphology, mechanical performance, and delivery efficiency are summarized. A comprehensive overview of recent studies is presented, highlighting successful applications across dermatological, infectious, ophthalmic, HIV-related, and neurodegenerative diseases. Collectively, the literature supports NC-loaded MNs as a patient-friendly approach that enables controlled dissolution, improved bioavailability, and sustained therapeutic levels. Overall, the integration of NC technology into MN systems represents a significant advancement in transdermal drug delivery, holding substantial potential to address limitations associated with low drug solubility and enhance therapeutic outcomes.