A Study to Evaluate Analgesic Efficacy and Safety of PRF-110 for Post-surgical Pain

Inclusion Criteria:

Inclusion criteria:

Subjects must meet all of the following criteria to be eligible for inclusion into the study:

1. Able to provide written informed consent prior to any study procedures.

2. Able to communicate clearly with the Investigators and study staff.

3. Males and females aged 18 years or older.

4. Scheduled for elective primary unilateral first metatarsal bunionectomy surgery (osteotomy and internal fixation) with no ancillary procedures.

5. Female subjects must be surgically sterile; or at least 2 years postmenopausal; orhave a monogamous partner who is surgically sterile; or practicing doublebarriercontraception; or practicing abstinence (must agree to use double-barriercontraception in the event of sexual activity); or using an insertable, injectable,transdermal, or combination oral contraceptive approved by the FDA for greater thantwo months prior to screening and commit to the use of an acceptable form of birthcontrol for the duration of the study and for 30 days after completion of the study.

6. Negative alcohol breath/saliva test and urine drug screen for drugs of abuse atScreening and at Baseline. Subjects with positive results on the alcoholbreath/saliva test or urine drug screen at Screening, and/or prior to surgery, willnot be allowed to proceed in the study unless the results can be explained by acurrent prescription or acceptable over-the-counter medication as determined by theInvestigator. Note that for those subjects who test positive fortetrahydrocannabinol (THC), if they are willing to abstain from use or consumptionof THC-containing products from Screening thru last Follow-up Visit, they may beallowed to participate in the study.

7. American Society of Anesthesiologists (ASA) Physical Status of I or II (seeAppendix, Section 14.1).

8. Body Mass Index (BMI) ≤35.

Exclusion Criteria:

subject will be excluded from the study if any of the following criteria are met:

1. Has clinically significant allergies to an opioid, unless has subsequently toleratedother opioids and, in the opinion of the Investigator, could tolerate a rescue drugcontaining oxycodone.

2. Has a known or suspected allergy to any local anesthetic or to acetaminophen.

3. Has a known or suspected history of alcohol, opiate or other drug abuse ordependence within 12 months prior to screening.

4. Is unable to refrain from alcohol consumption for a period beginning 24 hours priorto surgery through the end of the 72 -hour evaluation period.

5. Has taken any analgesic or non-opioid pain medication other than acetaminophen (e.g., NSAIDs, cyclooxygenase-2 [COX 2] inhibitors) within 12 hours prior to surgeryor any aspirin-containing product within 7 days of the Baseline assessments. Aspirinup to 325 mg once daily for cardiovascular prophylaxis is allowed.

6. Has taken any opioid analgesics or used systemic steroids within 4 days of surgery.

7. Has been using opiates or any non-steroidal anti-inflammatory drug chronically (morethan 10 consecutive days) anytime over the past 3 months.

8. Has used antipsychotics or antiepileptics within 30 days prior to surgery. Use ofsedatives, hypnotics, antianxiety agents, and antidepressants (other than monoamineoxidase inhibitors [MAOIs]) are allowed if being used for a nonpain indication andat a stable dose within the previous 30 days.

9. Has history of or positive test results for HIV or hepatitis B or C at Screening.

10. Has any history of epilepsy, other than childhood febrile seizures, before the ageof 6.

11. Has any history of psychosis, current clinically significant symptomatic psychiatricdisorder, or a history of suicide attempt in the past 10 years.

12. Has taken herbal agents or nutraceuticals (e.g., chapparal, comfrey, germander, jinbu huan, kava, pennyroyal, skullcap, St. John's wort, or valerian) during any of the 7 days prior to surgery that could potentially confound the analgesic response inthe Investigator's opinion.

13. Has transaminase levels > 2 x ULN, or bilirubin level > 1.5 x ULN (unless Gilbert'ssyndrome), or estimated glomerular filtration rate (eGFR) < 60 mL/min. Has poorlycontrolled diabetes with hemoglobin A1c >7.5%.

14. Has any clinically significant condition including an acute or chronic painfulphysical restrictive condition or any other significant laboratory abnormality thatwould, in the opinion of the Investigator, confound study assessments or adverselyaffect subject safety. 16. Has received another investigational drug within 30 daysof scheduled surgery.