Nano-Formulated Lower-Dose Oral Diclofenac Provides Acute Pain Relief

HONOLULU, HI—A nano-formulated, lower dose formulation of oral diclofenac may provide clinical benefit in relief of mild to moderate acute pain, results of a Phase 2 randomized trial presented during the American Pain Society’s 31st Annual Scientific Meeting have shown.

The study evaluated time to onset of analgesia of an investigational, proprietary, nano-formulated, lower-dose, oral diclofenac vs. placebo in an acute pain model, according to Garen Manvelian, MD, of Iroko Pharmaceuticals, LLC, Philadelphia, PA, and colleagues. One of the goals of developing new formulations of nonsteroidal anti-inflammatory drugs (NSAIDs) is to improve tolerability while maintaining efficacy.

The multicenter double-blind, single-dose, parallel-group, active- and placebo-controlled trial enrolled 202 subjects who had experienced moderate to severe pain intensity ≤6 hours following extraction of ≥2 third molars (≥1 of which was a fully or partially impacted mandibular third molar). Ages ranged from 18 to 50 years.

“Subjects assessed baseline pain intensity before receiving a single dose of nano-formulated lower dose diclofenac 18mg or 35mg, celecoxib 400mg, or placebo, and pain intensity and pain relief from 15 minutes through 12 hours,” Dr. Manvelian noted.

Compared with placebo (mean±SE; 144min±9.0), the nano-formulated lower dose diclofenac 35mg (42min±3.6), nano-formulated lower dose of diclofenac 18mg (36min±3.0), and celecoxib 400mg (54min±4.2) all had a significantly shorter time to onset of analgesia (P<0.001).

Improvement in mean time to first perceptible pain relief, mean time to meaningful pain relief, and mean time to peak pain relief for nano-formulated diclofenac 18mg and 35mg were also statistically significant when compared with placebo.

“Tolerability data were comparable for both nano-formulated diclofenac doses and celecoxib compared with placebo. Nano-formulated lower dose diclofenac demonstrated a faster time to onset of analgesia compared with placebo and was numerically better than celecoxib,” they found.

The investigators noted that these results are in line with the U.S. Food and Drug Administration directive to use the lowest effective NSAID dose.