Assessing Ethiqa XR Sterility Past the "Beyond-Discard Date" Under Conditions of Maximum Usage

Ethiqa XR is an FDA-indexed, extended-release, lipid-bound buprenorphine formulation providing 72 hours of opioid analgesia with a 90-day postbroach discard date. For small rodent studies, the standard vial frequently provides more drug than can be used within the 90-day labeled discard date, which can limit cost-effectiveness for researchers. This study evaluated whether sterility could be preserved for an additional 90 days beyond the labeled discard date through monthly testing for bacterial and fungal contamination, in addition to the presence of endotoxins. Twice weekly, each vial was wiped with 70% isopropyl alcohol, and a 20-gauge needle was inserted and then withdrawn, with samples removed from the vials at time points up to 180 days. All vials consistently remained free of bacterial, fungal, and endotoxin contamination throughout the study period and were sterile up to the final assessment at 180 days postbroaching. The concentration or efficacy of Ethiqa XR were not evaluated during this study.