A Study to Characterize Diclofenac's Plasma and Knee Exposure After Application of Diclofenac Gel to the Knee of Subjects With Osteoarthritis That Have a Scheduled Arthroplasty

Diclofenac Diethylamine (DDEA) gel consists of 2.32% DDEA. DDEA gel will be applied twice a day for 7 days topically first and last dose by trained nurse (or designee) at study site and doses in between by a trained nurse at participant's home or other convenient location. Participants will be admitted on the day before the scheduled surgery (Day 7). The last dose of study treatment will be administered at the study site 12 hours (window -1/+3 hrs) prior to arthroplasty surgery.If surgery is delayed by up to 7 days dosing with DDEA gel twice daily can continue up to 14 days. If the surgery is delayed by more than 7 days, the participant should be withdrawn from the study.

Placebo gel will be applied twice a day for 7 days topically first and last dose by trained nurse (or designee) at study site and doses in between by a trained nurse at participant's home or other convenient location. Participants will be admitted on the day before the scheduled surgery (Day 7). The last dose of placebo gel will be administered at the study site 12 hours (window -1/+3 hrs) prior to arthroplasty surgery. If surgery is delayed by up to 7 days dosing with placebo gel twice daily can continue up to 14 days. If the surgery is delayed by more than 7 days, the participant should be withdrawn from the study.