Analgesic efficacy and safety of the diclofenac epolamine topical patch 1.3% (DETP) in minor soft tissue injury

Abstract

The diclofenac epolamine topical patch 1.3% was designed to deliver analgesic concentrations of diclofenac to an underlying soft tissue injury site, while limiting systemic exposure to diclofenac. This randomized, double-blind, placebo-controlled study evaluated the safety and efficacy of the diclofenac epolamine topical patch for the treatment of acute pain due to minor soft tissue injury. Patients (18-65 years, inclusive) with clinically significant minor soft tissue injuries (mild or moderate sprain, strain, or contusion) incurred within 7 days of study entry and having pain scores ≥ 5 on a Visual Analog Scale of 0-10 were enrolled. Patients were randomized to receive the diclofenac epolamine topical patch (n=207) or placebo patch (n=211) application twice daily for 14 days or until pain resolution. Patients recorded pain scores every 12 h at the time of patch removal using the Visual Analog Scale. Investigator-assessed global response to therapy was also evaluated. Safety data were collected throughout the study. Twice-daily treatment with diclofenac epolamine topical patch produced a statistically significant reduction in mean pain score relative to baseline by an additional 18.2% in the diclofenac epolamine topical patch group (0.435 ± 0.268) compared with the placebo group (0.532 ± 0.293) (p=0.002; overall) beginning after application of the second patch. Consistent with this treatment effect, median time to pain resolution was shortened by 2 days in the diclofenac epolamine topical patch group relative to the placebo group (p=0.007). These results were reinforced independently by investigators who reported treatment as good or excellent for 58% of diclofenac epolamine topical patch-treated patients compared with 49% in the placebo patch group (p=0.008). The most common adverse events were treatment site related (n=16, 7.9% diclofenac epolamine topical patch; n=12, 5.8% placebo patch). Most (80%) patients reported tolerability as excellent or good. In conclusion, the diclofenac epolamine topical patch provides effective, rapid pain relief for the treatment of acute pain from minor soft tissue injury and appears generally safe and well tolerated.