Related Experiment Video
Updated: Aug 11, 2026
10:37
Development of Recombinant Proteins to Treat Chronic Pain
Published on: April 11, 2018
Long-acting narcotic antagonist complexes
National Institute on Drug Abuse Research Monograph Series
|January 1, 1976
Summary
Researchers developed novel drug formulations for opioid antagonists like naltrexone. Naltrexone zinc tannate and naltrexone aluminum tannate show promise for extended duration of action with minimal toxicity.
Area of Science:
- Pharmacology
- Materials Science
Background:
- Opioid antagonists are crucial for managing opioid overdose and addiction.
- Developing long-acting formulations can improve patient compliance and treatment efficacy.
Purpose of the Study:
- To explore the formation of water-soluble salts and drug:acid:metal complexes of opioid antagonists.
- To develop sustained-release formulations of narcotic antagonists with prolonged pharmacological action.
Main Methods:
- Screened nearly 100 organic acids for salt formation with methadone, cyclazocine, naloxone, naltrexone, and diprenorphine.
- Investigated drug:acid:metal complexes using polyvalent metal ions (Zn++, Al+++, Mg++, Ca++).
- Analyzed drug and metal content spectrophotometrically and assessed in vitro dissociation at pH 7.3.
Main Results:
- Identified organic acids forming insoluble salts with opioid antagonists.
- Developed and characterized drug:acid:metal complexes, establishing optimal conditions and consistent composition.
- Naltrexone zinc tannate and naltrexone aluminum tannate demonstrated prolonged in vivo activity in mice (tail-flick test) with no gross toxicity.
Conclusions:
- Naltrexone zinc tannate and naltrexone aluminum tannate are promising candidates for extended-release opioid antagonist therapy.
- Suspensions in aluminum monostearate gel represent a useful dosage form for these novel preparations.
Related Concept Videos
01:28Drug-Receptor Interaction: Antagonist
An antagonist is a drug that binds strongly to a receptor without activating it. An antagonist prevents other molecules, such as neurotransmitters or hormones, from binding to the receptor and triggering a cellular response. Such interaction effectively hinders the normal physiological processes mediated by the receptor, resulting in various pharmacological effects depending on the specific receptor targeted.
Antagonists can be classified as competitive or noncompetitive based on their...
Antagonists can be classified as competitive or noncompetitive based on their...
01:11Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacokinetics
All neuromuscular blocking agents are injected intravenously because they are poorly absorbed from the GI tract. Rapid onset is achieved with intravenous administration, although absorption is also adequate from an intramuscular injection. Since these agents are highly ionized, they do not readily penetrate cell membranes or cross the blood-brain barrier.
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
01:30Local Anesthetics: Chemistry and Structure-Activity Relationship
Local anesthetics (LAs) are drugs that induce a temporary loss of sensation in a limited body area, preventing pain. Cocaine was the first local anesthetic discovered in the late 19th century. Cocaine is a benzoic acid ester obtained from the leaves of coca shrubs and was often used for its psychotropic effects. Cocaine was first isolated in 1860 by Albert Niemann. Sigmund Freud studied the physiological actions of cocaine. Carl Koller later introduced it into clinical practice in 1884 as a...
01:23Local Anesthetics: Mechanism of Action
Local anesthetics (LAs) block sensory and motor impulses by inhibiting the sodium channels on the nerve cell membranes. This induces temporary loss of sensation, relieving pain in a specific body area.
Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either...
Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either...
01:22Opioid Receptors: Overview
Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2, D-Pen5]-enkephalin or DPDPE for...
01:15Opioid Analgesics: Synthetic and Semisynthetic Opioids
Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...