A Randomized, Double-Blind, Placebo-Controlled, Efficacy, Tolerability, Safety and Pharmacokinetic Study of Single Doses of DFN-15 in Post-Surgical Dental Pain

This is a Phase 2, single-center, randomized, double blind, dose-ranging placebo-controlled, clinical study evaluating the efficacy, tolerability, safety, and the pharmacokinetic properties of a known drug (selective COX-2 inhibitor) administered as an alternative formulation/dosage form (DFN-15, a liquid oral formulation) in an accepted model of acute post-operative pain (acute pain following oral surgery for extraction of bilateral impacted mandibular third molar teeth in otherwise healthy subjects).120 female and male healthy subjects scheduled to undergo elective bilateral third molar extraction will be randomized, after they provide informed consent and are confirmed to meet all the study selection criteria, in a 1:1:1:1 ratio to receive a single oral dose of either DFN-15 Dose A DFN-15 Dose B, DFN-15 Dose C or matching placebo.

Subjects will undergo a screening procedure (within 28 days of the scheduled extraction of the impacted third molars) that will involve the collection of demographic information, height, weight and body mass index (BMI), urine pregnancy test (women of child-bearing potential,) medical and medicinal history, physical examination, dental examination, vital signs measurement (blood pressure, pulse rate, respiratory rate), clinical laboratory investigation (hematology,serology, coagulation parameters, serum chemistry and urinalysis),12-lead ECG and a panoramic x-ray to document the impacted mandibular third molar teeth. As a pre-requisite for randomization, subjects will be required to report "moderate" to "severe" baseline pain on the provided paper diary within 6 hours post-surgery (called the 'Baseline' period) as characterized on a 4-point categorical pain intensity (PI) scale (0= none, 1= mild, 2= moderate, 3= severe), and a score of ≥5, on the 11-point Numerical Pain Rating Scale (NPRS) where 0 represents 'no pain' and 10 represents 'worst pain imaginable'. Eligible subjects will be randomized and will receive a single dose of the assigned study treatment. Subjects will be randomized and administered the study medication within 15 minutes of meeting the post-operative inclusion criteria (baseline score).Subjects will be assessed at pre-specified time-points over an observation period of 8 hours from the time of randomization.

Subjects with inadequately controlled pain symptoms may request rescue analgesic medication. Subjects will be encouraged to delay using the rescue medication if their pain is tolerable until 120 minutes post-dose of study medication. A subject who is administered rescue pain medication will continue completing pain assessments until 8 hours after treatment initiation. All randomized subjects will be provided with a paper diary to record pain assessments (Pain Intensity on 11-point NPRS scale, followed by Pain Relief using a 5-point categorical scale [where 0= no pain relief, 1= little pain relief, 2= some pain relief, 3= a lot of pain relief, 4= complete pain relief]) At study medication administration, two stopwatches will be started, to measure times to 'perceptible' and 'meaningful' pain-relief. Subjects will be instructed to stop the first stopwatch when they first perceive pain relief to occur (time to perceptible relief). Subjects will be instructed to stop the second stopwatch when they first experience meaningful pain relief (time to meaningful relief). Stopwatch times of perceptible relief and meaningful relief will be recorded using exact stopwatch time displayed.

In addition, at 8 hours post-dose or within 5 minutes prior to first use of rescue medication (whichever is earlier), subjects will be asked to record within the provided patient diary: 'Patient Rating of Treatment Satisfactoriness' using a 5-point verbal rating scale (0 =poor, 1 =fair, 2 =good, 3=very good, 4 =excellent).

Subjects will remain NPO (nothing by mouth), including water, from Check-in (i.e., at least 2 hours before the administration of the dose of study medication to randomized subjects) until 2 hours post-dose, on Day 1 (study day). After 2 hours post-dose, subjects may be permitted to consume water, or gelatin snacks. Subjects are prohibited from ingesting solid foods or carbonated beverages for at least 6 hours post-dose.