Inclusion Criteria:
Subjects must meet all of the following criteria to be included in the study:
* Healthy male or female volunteer, aged 18-to-55 years, inclusive.
* BMI must be between 18 and 32 kg/m2 (inclusive) and weigh a minimum of 50 kg (110 lbs).
* If female, be postmenopausal (at least 2 years prior to dosing) or agree to use an acceptable form of birth control from screening until 12 weeks after dosing. Subjects who claim postmenopausal status will have status confirmed with a follicle stimulating hormone (FSH) test. Acceptable forms of birth control for females include the following:
* Vasectomized partner (at least 6 months prior to dosing)
* Surgical sterilization (bilateral tubal ligation, hysterectomy, bilateral oophorectomy) at least 6 months prior to dosing
* Non-surgical permanent sterilization (eg, Essure procedure) at least 3 months prior to dosing.
* Abstinence (must agree to use a double barrier method if they become sexually active during the study)
* Double barrier (diaphragm with spermicide; condoms with spermicide)
* Oral hormonal contraceptives
* Not Breast feeding
* Negative tests for human immunodeficiency virus (HIV), Hepatitis C antibody, Hepatitis B surface antigen, and Covid
* Able and willing to comply with the requirements of the protocol
* Able and willing to provide written informed consent
* Willing to undergo a minor surgical procedure under local anesthetic to allow for investigational drug administration in the subcutaneous tissue
* Agree to avoid blunt trauma to the implantation site
* Agree that after implantation, not to shower for 2 days and not to bathe/swim for 4 weeks
Exclusion Criteria:
Subjects must have none of the exclusion criteria to be included in the study.
* Clinically significant abnormal finding on the physical exam, medical history, electrocardiogram (EKG), or clinical laboratory results at screening. In particular, values of liver function tests (ALT, AST, bilirubin, albumin, GGT) and kidney function tests (creatinine, blood urea nitrogen) and reticulocytes shall not deviate by more than 25% from the ranges of normal.
* Blood pressure: systolic \>140 mmHg, diastolic \>90 mmHg. \[Europe Soc Hypertension guidelines\]
* Heart rate: \>100 beats/minute.
* Hemoglobin for female \<11.5 and for male \<12.5 are excluded.
* Have a known or suspected history or family history of adverse reactions or hypersensitivity to the study drugs or to drugs with a similar chemical structure.
* History or presence of gastrointestinal, hepatic or renal disease, or other condition known to interfere with the absorption, distribution, metabolism or excretion of drugs.
* Is on anticoagulant medications other than aspirin or NSAIDs. Agree to stop aspirin or NSAIDs 1 week prior to Biopin 6 implantation
* Used any over-the-counter (OTC) medication, nutritional or dietary supplements, herbal preparations, or vitamins within 7 days prior to the first dose of medication.
* Used any prescription medication within 14 days prior to the first dose of study medication.
* More than moderate drinking averaged over the last month as assessed by history:
o Moderate drinking is here defined as up to 3 drinks per week. The standard drink will be defined by the guidelines of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and will contain no more than 14 g of alcohol.
* Smoking: Use of tobacco or nicotine-containing products within the 3-month period preceding study drug administration is exclusionary.
* Positive urine drug screen for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, cannabinoids, phencyclidine, propoxyphene, methadone, methaqualone, and alcohol at the screening and Day -1 tests.
* Any methadone use 14 days prior to screening, and up to Study Day -1.
* Has had a naltrexone implant in the past 24 months.
* Has received treatment with an extended naltrexone product (e.g. Vivitrol) in the past 12 months.
* Fails the naloxone challenge test
* Has a condition which requires treatment with opioid based medication.
* Has a known hypersensitivity to naltrexone.
* Has a known hypersensitivity to materials based on poly-d-l Lactic Acid and polycaprolactone (e.g. biodegradable sutures, surgical implants or previous biodegradable implants).
* Has a known hypersensitivity to local anesthesia.
* Is prone to skin rashes, irritation or has a skin condition such as recurrent eczema that is likely to impact the implant site area, or as determined by the evaluating physician.
* Is known to form keloids at the site of skin injury.
* Demonstrates any abnormal skin tissue in the proposed implantation area
* Previous surgery to the upper abdominal wall
* Donated blood or plasma within 30 days prior to the first dose of study medication.
* Participated in another clinical trial within 30 days prior to the first dose of study medication.
* Is participating or intending to participate in any other clinical trial during the duration of this study.
* Any elevated risk for suicide measured using the Columbia Suicide Severity Rating Scale, endorsing any of the items in the past month (C-SSRS, Lifetime)
* Not as much as "mild" depression as measured by the HAM-D17 test: HAM-D17 score must be 0-10.
* Any additional condition(s) that in the investigator's opinion would prohibit the participant from completing the study or would not be in the best interest of the participant.
