Conclusion: Vocacapsaicin is being developed as a novel, water-soluble prodrug that allows for infiltration into surgical sites. In vivo observations in rats are consistent with the rapid conversion to capsaicin measured in vitro at physiologic-simulating conditions. In rats, vocacapsaicin converts efficiently, providing capsaicin exposure comparable to equimolar capsaicin administration. Vocacapsaicin was also shown to be stable in moderately acidic solutions, allowing for dose formulation preparation without complex excipients.

This work, along with data showing clinical efficacy in patients following total knee arthroplasty, bunionectomy, and ventral hernia repair, demonstrates that vocacapsaicin allows for efficient delivery of capsaicin, a TRPV1 agonist, to the surgical site. Vocacapsaicin is currently in Phase 3 clinical development for the treatment of postsurgical pain.