A Study of Intramuscular Sebacoyl Dinalbuphine Ester for Post-Hemorrhoidectomy Pain Management

Inclusion Criteria:

• Male or female >= 20 years of age at Screening

• Scheduled to electively undergo 2 or 3-column excisional hemorrhoidectomy

• American Society of Anesthesiology Physical Class 1 - 3

• Adequate clinical lab values (values of potential clinical concern are detailed inAppendix) or, if abnormal, deemed not clinically significant per the Investigator.

• Ability and willingness to provide informed consent, adhere to the study visitschedule and complete all study assessments and language specific questionnaires

Exclusion Criteria:

• Body weight less than 40 kg.

• Concurrent fissurectomy.

• Subject is pregnant or breastfeeding. Women of childbearing potential must have anegative urine pregnancy test at Baseline.

• Women of childbearing potential disagree to use an acceptable method of contraception (e.g., hormonal contraceptives, IUD, barrier device or abstinence) throughout thestudy.

• History of hypersensitivity or allergy to amide-type local anesthetics, opioid, or anyingredient of the medications administered in this study.

• Subject has a resting respiratory rate less than 8 per minute and blood oxygensaturation less than 90 mmHg.

• Use of any NSAIDs, selective COX-2 inhibitors, opioid, acetaminophen, selectiveserotonin reuptake inhibitors (SSRI), tricyclic antidepressants (TCA), gabapentin, orpregabalin within three days of surgery.

• Chronic use of opioid medications for more than 14 days in the last 3 months, ornon-opioid pain medications more than 5 times per week before screening visit.

• Use of any long-acting opioid medication within 3 days of surgery or any opioidmedication within 24 hours of surgery.

• Current painful physical condition or concurrent surgery requires analgesic treatmentin the postoperative period.

• Contraindication to epinephrine or any of the pain-control agents planned forpostoperative use.

• Administration of an investigational drug within the longer of 30 days or 5elimination half-lives of such investigational drug prior to study drugadministration.

• Any psychiatric disorder, psychological, medical, or laboratory condition that mayinterfere with study assessments or compliance.

• Significant medical conditions or laboratory results that may indicate an increasedvulnerability to study drugs and procedures, and thus expose the subject to anunreasonable risk as a result of participating in this clinical trial.

• Any clinically significant event or condition may be uncovered during surgery.

• History of abuse illicit drugs, prescription medicines or alcohol within the past 2years.

• Known history of anti-HIV antibody positive

• Failure to pass drug and alcohol screen.