Nalorphine API Manufacturers & Suppliers

Nalorphine (CAS Number 62-67-9) is a mixed opioid agonist–antagonist belonging to the morphinan class of compounds. Morphinans are characterized by a polycyclic four-ring structure, including a partially hydrogenated phenanthrene moiety comprised of three condensed six-membered rings. Nalorphine acts selectively at opioid receptors, exhibiting antagonistic activity at the mu-opioid receptor and high-efficacy agonist effects at kappa-opioid receptors.

Clinically, nalorphine has been used to reverse opioid overdose due to its ability to competitively inhibit mu-opioid receptors, thereby counteracting the respiratory depression and central nervous system effects induced by opioid agonists. In addition, starting in the 1950s, nalorphine was utilized in challenge testing to assess opioid dependence by precipitating withdrawal in dependent individuals.

The pharmacological profile of nalorphine as a mixed agonist–antagonist contributes to its unique mechanism of action; it blocks mu receptor-mediated opioid effects while activating kappa receptors, which can produce analgesia, dysphoria, and psychotomimetic effects. This dual activity influences both its therapeutic applications and safety profile.

Pharmacokinetic details such as absorption, distribution, metabolism, and excretion (ADME) parameters are not extensively characterized in current literature, limiting detailed description of its disposition and elimination.

Safety and toxicity considerations include the potential for precipitating withdrawal symptoms in opioid-dependent patients and central nervous system effects related to kappa receptor activation, including dysphoria and hallucinations at higher doses.

Nalorphine is classified under multiple pharmacological categories including opioid antagonists, mixed agonist-antagonists, and semi-synthetic opiates. Its regulatory status is largely experimental or veterinary approved, reflecting limited contemporary clinical use.

When sourcing nalorphine as an active pharmaceutical ingredient (API), attention should be given to the compound’s stability profile and strict adherence to Good Manufacturing Practice (GMP) standards. Purity assessments should confirm the absence of structurally related impurities due to its fused-ring morphinan structure. Verification of supplier compliance with relevant pharmacopeial monographs and regulatory requirements is essential to ensure consistent quality and safety for formulation development or veterinary applications.