Rapidly Dissolving Microneedles Incorporating Lidocaine Hydrochloride: A PVP/PVA-Based Approach for Local Anesthesia

Abstract

Background/Objectives: Lidocaine is a widely used local anesthetic, but injections and topical creams are often painful or slow in onset. This study aimed to develop dissolving microneedles incorporating lidocaine hydrochloride for rapid and convenient local anesthesia. Methods: Six formulations were prepared with polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) and evaluated for mechanical strength, skin insertion, drug release, and transdermal permeability. Results: Sharp pyramidal microneedles were successfully fabricated, with PVP–PVA mixtures producing stronger needles than single polymers. The optimized F5 formulation showed high strength (>32 N), efficient skin insertion (four parafilm layers), and rapid release (>80% within 15 min). In ex vivo studies, F5 delivered >600 µg/mL lidocaine in 15 min, over three times the therapeutic level and much faster than Emla cream (5%). Conclusions: PVP–PVA microneedles represent a promising platform for painless, rapid local anesthesia, combining the benefits of injections and topical creams while minimizing their drawbacks.