This is a Phase 3, randomized, double-blind, placebo-controlled study in subjects scheduled to undergo elective bilateral third molar extraction under local anesthesia. At least one lower mandibular third molar must involve full or partial bony impaction confirmed by visual or radiographic evidence.

Subjects will be screened within 30 days prior to surgery.

Randomized subjects will receive a dental nerve block with lidocaine 2% with epinephrine 1:100,000 before undergoing bilateral third molar extraction under local anesthesia. In addition to the lidocaine nerve block, the Investigator may choose to add topical benzocaine or intraoperative nitrous oxide.

At the end of surgery, and at least 20 minutes after the lidocaine administration, blinded study drug will be infiltrated to provide postsurgical analgesia. Subjects will be required to remain in the research facility for 96 hours after study drug administration.

Postsurgical efficacy, safety, and pharmacokinetic (PK) assessments will be conducted.

All subjects will return for a follow-up visits on Days 7 and 10. A phone call will be made to each subject on Day 30 for an adverse event (AE) assessment and to inquire as to whether the subject made any unscheduled phone calls or office visits related to pain.

Inclusion Criteria:

1. Male or female, ≥18 years of age at screening.
2. Scheduled to undergo bilateral third molar extractions (i.e., extraction of all four third molars) under local anesthesia. At least one lower mandibular third molar must involve full or partial bony impaction confirmed by visual or radiological evidence.
3. American Society of Anesthesiology (ASA) physical status 1, 2, or 3.
4. Female subjects must be either surgically sterile, using a medically acceptable method of birth control, or at least 2 years postmenopausal, and must have a documented negative pregnancy test result during screening and on Day 1 prior to surgery.
5. Able to provide informed consent, adhere to the study visit schedule, and complete all study assessments.

Exclusion Criteria:

1. History of hypersensitivity or idiosyncratic reaction to amide-type local anesthetics or opioids.
2. Contraindication to lidocaine, epinephrine, bupivacaine, or oxycodone.
3. History of significant drug allergy (e.g., anaphylaxis or hepatotoxicity).
4. Positive test result from the urine drug screen at screening or prior to the surgical procedure.
5. Currently pregnant, nursing, or planning to become pregnant during the study or within 1 month after study drug administration.
6. History or active psychiatric illness (including major depression, bipolar disorder, or anxiety); Type 1 or Type 2 diabetes; severe renal or hepatic impairment; significant cardiovascular disease (including cardiac rhythm disturbance); migraine headaches, frequent headaches, other pain conditions, or other medical condition that, in the opinion of the Investigator, may increase the risk of surgery or interfere with the evaluation of the study drug.
7. History of infection requiring intravenous (IV) antibiotics within 45 days or oral (PO) antibiotics within 30 days prior to study drug administration for reasons other than dental prophylaxis. Subjects must be afebrile, without signs or symptoms indicative of active infection.
8. Use of any of the following medications within the times specified before surgery: long-acting opioid medication, nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin (except for low-dose aspirin used for cardioprotection), or acetaminophen within 3 days, or any opioid medication within 24 hours.
9. Initiation of treatment with any of the following medications within 1 month of EXPAREL infiltration or if the medication(s) are being given to control pain: selective serotonin reuptake inhibitors (SSRIs), selective norepinephrine reuptake inhibitors (SNRIs), gabapentin, pregabalin (Lyrica®), or duloxetine (Cymbalta®). If a subject is taking one of these medications for a reason other than pain control, he or she must be on a stable dose for at least 1 month prior to EXPAREL administration.
10. Current use of systemic glucocorticosteroids within 1 month of enrollment in this study.
11. Use of any concurrent therapy that could interfere with the evaluation of efficacy or safety, such as any drugs which in the Investigator's opinion may exert significant analgesic properties or act synergistically with the investigational product.
12. Administration of an investigational drug within 30 days or 5 elimination half-lives of such investigational drug, whichever is longer, prior to study drug administration, or planned administration of another investigational product or procedure during the subject's participation in this study.

Safety population included all participants who received study drug, with analysis by actual treatment received.

From screening to postsurgical day 29

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans whether or not considered drug-related. An AE could therefore have been any unfavorable and unintended sign (eg abnormal laboratory finding), symptom, or disease temporally associated with the use of a drug without any judgment about causality. Serious AEs were defined as per clinicaltrials.gov.

The safety analysis set included all subjects who received study drug, based on the treatment received.