Noscapine, also known as narcotine, nectodon, nospen, anarcotine and opiane, is a benzylisoquinoline alkaloid of the phthalideisoquinoline structural subgroup, which has been isolated from numerous species of the family Papaveraceae. Chemically it is C22H23NO7 with a molecular weight of 413.42 g mol and a phthalide-fused isoquinoline core that confers lipophilicity and a characteristic crystalline morphology with a melting range near 175 to 177 degrees Celsius. Pharmacologically noscapine is best known as a central antitussive agent with low affinity for classical opioid receptors and a distinct mechanism that includes reversible binding to tubulin and modulation of microtubule dynamics, properties that have prompted investigation in oncology as a noncanonical microtubule-interacting compound. It is sparingly soluble in water and more soluble in polar organic solvents, undergoes hepatic metabolism with phase I and II transformations, and is typically formulated for oral dosing when used clinically in regions where it is marketed.
![(3S)-6,7-Dimethoxy-3-[(1R)-1,2,3,4-tetrahydro-6,7-dihydroxy-8-methoxy-2-methyl-1-isoquinolinyl]-1(3H)-isobenzofuranone](https://veeprho.com/wp-content/uploads/2024/12/VE0022489-3S-6-7-Dimethoxy-3-1R.png "(3S)-6,7-Dimethoxy-3-[(1R)-1,2,3,4-tetrahydro-6,7-dihydroxy-8-methoxy-2-methyl-1-isoquinolinyl]-1(3H)-isobenzofuranone")
Parent: Noscapine
Pharmaceutical grade noscapine is supplied to meet tight impurity controls because plant extraction routes may co-extract structurally related alkaloids and process impurities; a typical specification for a finished active pharmaceutical ingredient is an assay not less than 98.0 percent w w, total related substances not greater than 1.0 percent w w and any individual related alkaloid or unspecified impurity normally limited to 0.2 to 0.5 percent w w depending on regulatory or customer requirements. Related compounds that are monitored include other Papaveraceae alkaloids such as papaverine, laudanosine, thebaine, codeine and morphine when present as tracelevel contaminants from botanical material or crosscontamination during processing; residual solvents, inorganic residues and degradation products are controlled to pharmacopeial and ICH thresholds and characterized by validated analytical methods such as HPLC and LC MS to ensure batchto batch consistency.
Noscapine is primarily used as an antitussive agent to suppress cough in clinical practice in some countries and is researched as an investigational microtubule modulator for potential anticancer applications; its clinical use as a cough suppressant is based on central nervous system activity distinct from classical opioid analgesia.
Noscapine is structurally an opium poppy alkaloid but it has minimal activity at opioid receptors and is not classified as an opioid analgesic; it exerts antitussive and cytoskeletal effects through different pharmacology than morphine or codeine.
Codeine is a classical opioid that acts primarily via mu opioid receptors to produce analgesia and cough suppression and has abuse and dependence liability, whereas noscapine lacks significant opioid receptor agonism, has a different chemical scaffold within the benzylisoquinoline family, and produces antitussive effects with much lower abuse potential and distinct secondary activities such as tubulin modulation.
Noscapine is not approved as an over the counter or prescription cough medicine by the US Food and Drug Administration as a marketed product in the United States; it has been used clinically in other jurisdictions and continues to be evaluated in clinical research settings for noncough indications.
