Electrospun PLGA nanomembrane: A novel formulation of extended-release bupivacaine delivery reducing postoperative pain

Efficacy and safety are fundamental qualities to uphold and improve when developing an extended-release carrier system for local anesthetics (LAs). This is especially true as diverse analgesics are applied in multimodal analgesia regimens and interactions between drugs may lead to adverse events. Here we propose a new formulation of LA carrier delivery: a PLGA nanomembrane produced by electrospinning technique that allows improved analgesia and better compatibility with combination analgesia regimen. In vitro release profile of this nanomembrane exhibited prolonged release profile (~35 days) compared to other extended-release systems of LAs studied so far. In vivo bupivacaine delivered through nanomembrane showed superior and prolonged analgesia compared to lidocaine infiltration in rat model of postoperative pain. Furthermore, in vivo safety profile of nanomembrane in single or combined use was confirmed by symptomatic, histological and pharmacokinetic analysis. These results indicate a novel formula of extended-release system that may potentiate better safety and analgesia of LAs compared to available extended-release products of LAs.