Proof-of-concept Study of NSAID Hydrogel Patch in Treatment of Acute Pain

Inclusion Criteria: 1. Subject must be a male or female aged 18 to 65 years, inclusive. 2. Subject must have a diagnosis of uncomplicated acute minor ankle sprain of Grade I or II as defined by the AAOS criteria. 3. Ankle sprain must have occurred \<48 hours prior to Screening. 4. Subject must have a baseline self-evaluated pain score of \>50 mm on a 100 mm VAS while bearing weight on the affected ankle. 5. Female subjects of childbearing potential must have a negative serum pregnancy test at Screening and be willing to use an acceptable form of birth control from the day of the first dose administration to 30 days after the last administration of the study product. 6. Subject must be willing to refrain from using any other pain medication (other than allowed rescue medication) during their participation. Exclusion Criteria: 1. Subject is a pregnant, breastfeeding, or lactating female. 2. Subject has an acute ankle sprain of Grade III as defined by AAOS criteria. 3. Subject has an ankle fracture as confirmed by X-ray. 4. Ankle sprain requires surgical treatment. 5. Subject has experienced recurrent sprains (≥3 sprains of the same joint) or has sprained the affected joint within the last 12 months. 6. Subject has taken analgesics other than NSAID(s) or acetaminophen for any purpose within 7 days of Screening. 7. Subject has taken flurbiprofen or naproxen within 24 hours of Screening. 8. Ankle sprain is treated prior to Screening by ultrasound, physical therapy, or acupuncture. 9. Subject has used immunomodulators or immunosuppressive therapies (e.g., interferon, oral or parenteral corticosteroids, and cytotoxic drugs) within 4 weeks prior to randomization. 10. Subject has used any medicated topical agents (e.g., medicated creams or lotions) on the affected ankle within 7 days prior to Screening. 11. Subject is currently using any other medications that, in the opinion of the Investigator, may exacerbate or mask the anticipated side effects of NSAIDs or interfere with the Investigator's ability to monitor for them (e.g., blood thinners or proton-pump inhibitors). 12. Subject has non-intact or damaged skin in the area to be treated (e.g., eczema, psoriasis, exudative dermatitis, infected lesion, burn, or wound). 13. Subject has a history of ulcers, GI bleeding, hypertension, edema, heart failure, or CV disease. 14. Subject has asthma (except childhood asthma), urticaria, angioedema, or bronchospasm. a.A subject is eligible for the study if they have had no symptoms of these conditions that required medication in the 5 years prior to Screening. 15. Subject has a history of any chronic pain disorder. 16. Subject has coagulation defects. 17. Subject has a history of severe cardiac, renal, or hepatic impairment within 12 months prior to Screening that, in the opinion of the Investigator, would interfere with the outcome of the study. 18. Subject has a severe systemic disease (e.g., cancer or severe acute infection). 19. Subject has a known allergy or hypersensitivity to flurbiprofen, aspirin, other NSAID(s), or any excipient in the IP. 20. Subject has any systemic or dermatologic disorder that, in the opinion of the Investigator, will interfere with the study results or increase the risk of AEs. 21. Subject has a history of uncontrolled chronic or acute concomitant disease that, in the Investigator's opinion, would contraindicate study participation or confound interpretation of the results. 22. Subject has applied ice or compression to the affected ankle within 2 hours prior to Screening. 23. Subject has a bilateral ankle injury. 24. Subject has an ipsilateral knee injury. In the opinion of the Investigator, are unsuitable for inclusion in the study.