Lidocaine-Loaded Iontophoresis-Driven Fiber-Based Microneedle Patch for Controllable and Long-Lasting Transdermal Local Analgesia

Abstract The acute pain induced by clinical procedures, such as venipuncture, dental operations, and dermatological treatments, as well as postoperative pain, drives the advancement of anesthetic techniques aimed at alleviating discomfort. This situation underscores the ongoing significance of effective pain management strategies within the field of anesthesia. This paper presents an integrated iontophoresis (ITP)-driven fiber-based microneedle patch (IFMP) regulated by a smartphone for controllable, long-lasting lidocaine transdermal delivery. The IFMP integrates pure cotton fiber canvas-based dissolving microneedles (MNs) with ITP into a patch, with the MNs tips and gel layers significantly increasing the drug-loading capacity, achieving a one-step drug administration strategy of “dissolution, diffusion, and ITP.” Lidocaine is released via the microchannels of MNs by passive diffusion. Additionally, an electric current initiates active ITP for lidocaine delivery, creating synergy. User-requirement-based drug release by precisely modulating electrical signals in rat pain models is described herein. A smartphone application enables precise dosage control. It offers three different delivery modes: single-dose, pulse delivery, and sustained-release, ensuring rapid onset, and long-lasting pain relief. This versatility makes the system suitable for various pain conditions. The IFMP represents a promising system for patient-controlled local analgesia treatment, enabling active and long-term local self-controlled pain management in a safe and regulated manner. Graphical Abstract The iontophoresis-driven fiber-based microneedle patch combines fiber-based dissolving microneedles with iontophoresis, facilitating controlled lidocaine release through diffusion and electrical activation for enhanced effect. Precise modulation of electrical signals allows user-requirement-based drug release in rat pain models. A smart application supports precise dosing in single-dose, pulse, or sustained-release modes, ensuring efficient and prolonged pain management.