A representative lot is a 5:1 E:Z mixture.
It is used as a tool in neurobiological research. Prototype vanilloid receptor agonist. Topical analgesic.
Off-White Crystalline Solid
analgesic (topical), depletes Substance P, neurotoxic
As a tool in neurobiological research.
Application in Particular Diseases
- Capsaicin, an extract of red peppers that causes release and ultimately depletion of substance P from nerve fibers, has been beneficial in providing pain relief in OA when applied topically over affected joints. It may be used alone or in combination with oral analgesics or NSAIDs.
- To be effective, capsaicin must be used regularly, and it may take up to 2 weeks to work. It is well tolerated, but some patients experience temporary burning or stinging at the site of application. Patients should be warned not to get the cream in their eyes or mouth and to wash their hands after application.
- Application of the cream, gel, or lotion is recommended four times daily, but tapering to twice-daily application may enhance long-term adherence with adequate pain relief.
Prototypic vanilloid receptor agonist (pEC 50 values are 7.97 and 7.10 at rat and human VR1 receptors respectively). Excites a subset of primary afferent sensory neurons, with subsequent antinociceptive and anti-inflammatory effects. Reversibly inhibits aggregation of platelets. Also available as part of the Vanilloid TRPV1 Receptor Tocriset™ .
K channel blocker; multiple sclerosis therapy
Capsaicin analogue (C175680). It is used as a tool in neurobiological research. Prototype vanilloid receptor agonist. Topical analgesic.
Capsaicin is used in many topical ointments used to relieve the pain of peripheral neuropathy (treatment of pain in the nerve endings near the surface of the skin).
Recrystallise capcaicin from pet ether (b 40-60o), or pet ether/Et2O (9:1). Also purify it by chromatography on neutral Al2O3 (grade V) and elute successively with *C6H6, *C6H6/EtOAc (17:3) then *C6H6/EtOAc (7:3), and distil it at 120o/10-5mm, then repeatedly recrystallise the needles from isopropanol (charcoal). [Crombie et al. J Chem Soc 11025 1955, Bennett & Kirby J Chem Soc(C) 442 1968.] It causes pain and is neurotoxic [Bevan & Szolcsanyi Trends in Pharmacol Sci 11 330 1990, Beilstein 13 IV 2588].