Optimization and Characterization of Polymeric Microneedle Patches for Enhanced Transdermal Delivery of Cyanocobalamin

This study addresses the challenge of transdermal delivery of cyanocobalamin (vitamin B12), a hydrophilic macromolecule with low permeability, by developing biodegradable polymeric microneedle (MN) patches. Conventional methods often suffer from poor bioavailability, but microneedle technology can bypass the stratum corneum barrier, thereby improving drug delivery efficiency. We fabricated MN patches using hydroxypropyl methylcellulose (HPMC K4M), polyvinylpyrrolidone (PVP K30), and polyethylene glycol (PG 4000) through a mold-casting technique, followed by characterization of drug content, release kinetics, and mechanical properties. The optimized formulation (M18) demonstrated high drug content (95.2%) and sustained release (96.4% at 24 hours), while FTIR confirmed no drug-polymer interactions, ensuring stability. Moreover, SEM revealed uniform needle dimensions (867.25 ± 7.35 µm in height), and texture analyzer tests validated robust mechanical integrity. The patches exhibited low moisture content (3.42%) and high folding durability (>200 folds), indicating suitability for storage and application. These results highlight the potential of polymeric MN patches as a non-invasive, efficient alternative for transdermal delivery of hydrophilic macromolecules. The study contributes to the field by providing a scalable, stable, and high-performance delivery system, which could significantly impact treatments for vitamin B12 deficiency and similar therapeutic needs.