Title
Nanoparticle loaded fast-dissolving microneedle patch for local delivery of anesthetic agent – dual-action approach
Authors
DAHAI QIU, YAO LI, JUN XU and ZULCAIF AHMAD

Received July 2, 2025
Published Volume 59 Issue 9-10 October-December
Keywords anesthesia, microneedles, nanoparticles, transdermal drug delivery system, lidocaine

Abstract
This study aimed to develop a dual-action fast-dissolving microneedle patch (FDMN) through which lidocaine could be delivered transdermally and to obtain a combined effect with free drug for rapid onset and nanoparticles for sustained release. First, chitosan-based nanoparticles were tried, but found incompatible with HA-PVP microneedle matrix, then HPMC-based nanoparticles were prepared and proceeded. The average particle size of nanoparticles was 71.4 ± 2.28 nm with PDI of 0.312. Zeta potential was -0.1 mV. Drug entrapment and loading efficiencies were found to be 94.5 ± 1.93% and 8.5 ± 0.65%, respectively. The FDMN6 patch had suitable morphology, consistent thickness (0.173 ± 0.01 mm) and mechanical strength. Ex-vivo studies showed 92.87 ± 0.88% lidocaine release over 480 minutes, following first-order kinetics (R² = 0.983). The patch was biocompatible and in-vivo testing confirmed a rapid onset and prolonged anesthetic effect up to 480 minutes. The dual-action FDMN6 patch provides a pain-free alternative for localized anesthesia. It offers immediate and sustained delivery of lidocaine. Its safety, ease of application and extended efficacy highlighted its potential for minor surgical procedures.