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Sustained release of naltrexone from glyceride implants
National Institute on Drug Abuse Research Monograph Series
|January 1, 1976
Summary
Injectable implants made from naltrexone and natural glycerides offer sustained release of narcotic antagonists. These implants effectively block morphine
Area of Science:
- Pharmacology and Drug Delivery
- Biomaterials Science
Background:
- Naltrexone is a potent narcotic antagonist.
- Continuous delivery systems are needed for long-term therapeutic effects.
Purpose of the Study:
- To develop and evaluate injectable implants for sustained in vivo release of naltrexone.
- To control naltrexone release rates and assess implant biocompatibility.
Main Methods:
- Formulation of solid dispersions of naltrexone in natural glycerides into pellets and microparticles.
- In vivo testing in mice to assess naltrexone delivery and blockade of morphine's anti-nociceptive effects.
- Evaluation of implant degradation, absorption, and tissue compatibility in various animal models.
Main Results:
- Both implant forms delivered naltrexone effectively for over one month in mice.
- Naltrexone release rates were tunable by adjusting drug concentration and glyceride composition.
- Implant degradation and absorption varied with composition, size, and anatomical location.
- No significant tissue incompatibility was observed across multiple species.
Conclusions:
- Injectable naltrexone implants in natural glycerides provide a viable long-term delivery system.
- The system allows for controlled release and demonstrates excellent biocompatibility in preclinical models.
- This technology holds promise for sustained blockade of opioid effects.
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