Refined Dual-Stage Release of Lidocaine by Erodible Microneedles for Postoperative Analgesia

Effective postoperative pain management is crucial for major and minor surgeries, yet conventional approaches often fall short due to limitations in duration, dosing, or convenience. This study introduces an innovative microneedle-based drug delivery system highlighted by a refined dual-stage release profile to enhance surgical wound analgesia. The proposed erodible microneedle (EMN) contains two polymer networks, namely polyvinyl pyrrolidone (PVP) and poly(lactic-co-glycolic acid) (PLGA), and carries the effective local analgesic lidocaine hydrochloride (LIDH). The PVP network rapidly dissolves initially, releasing enough LIDH and efficiently alleviating severe postoperative pain during the early stage. Simultaneously, channels were created on the remaining PLGA-based needles, ensuring continuous and sufficient drug delivery of LIDH over a prolonged period. Accordingly, the EMN administration system provides a refined dual-stage release mechanism tailored to address the dynamic nature of postoperative pain, ensuring rapid onset for acute pain relief while maintaining sustained drug delivery for long-term analgesia. Thus, the EMN@LIDH patch represents a noteworthy advancement in postoperative analgesia since it provides a novel, minimally invasive analgesic approach that balances sustained therapeutic effects, drug dosage, and treatment compliance and can significantly improve the postoperative experience for patients regarding pain management.