Microneedle Based Drug Delivery Systems: Recent Formulation Advances and Clinical Developments

Abstract

Background: Microneedle (MN) technology represents a paradigm shift in drug delivery, bridging the gap between conventional transdermal patches and hypodermic injections. By creating micron scale conduits through the stratum corneum, MNs enable the delivery of both small molecules and large biologics with minimal pain and patient discomfort.  

Objective: This review comprehensively examines recent advances in MN formulation strategies including dissolving, hollow, coated, solid, and hydrogel-forming systems and integration with nanocarriers such as liposomes, polymeric nanoparticles, and lipid nanoparticles. It also critically appraises recent clinical trial data and regulatory considerations.

Methods: A systematic literature search was conducted using PubMed, Scopus, Web of Science, and Clinical Trials.gov (2015–2024). Studies reporting preclinical or clinical outcomes of MN mediated drug or vaccine delivery were included.

Results: Dissolving MNs fabricated from hyaluronic acid, polyvinylpyrrolidone, and silk fibroin demonstrate excellent biocompatibility and reproducible pharmacokinetics for vaccines, hormones, and peptides. Clinical trials confirm non-inferior immunogenicity for influenza, measles-rubella, and COVID-19 vaccines, with marked improvements in patient preference. Nanocarrier integrated MN systems further improve thermostability, drug encapsulation efficiency, and targeted release. Challenges including mechanical robustness, drug stability during fabrication, regulatory pathways, and scale-up manufacturing remain active areas of investigation.  

Conclusion: MN technology is transitioning from bench to bedside, with several systems in advanced clinical trials. Continued interdisciplinary collaboration among materials scientists, pharmacologists, and clinicians is essential to accelerate regulatory approval and widespread clinical adoption.