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C19H27NO 285.43

2,6-Methano-3-benzazocin-8-ol, 1,2,3,4,5,6-hexahydro-6,11-dimethyl-3-(3-methyl-2-butenyl)-, (2,6,11R*)-.
(2R*,6R*,11R*)-1,2,3,4,5,6-Hexahydro-6,11-dimethyl-3-(3-methyl-2-butenyl)-2,6-methano-3-benzazocin-8-ol [359-83-1].
» Pentazocine contains not less than 98.0 percent and not more than 101.5 percent of C19H27NO, calculated on the dried basis.
Packaging and storage— Preserve in tight, light-resistant containers.
Solution: 80 µg per mL.
Medium: 0.01 N hydrochloric acid.
Absorptivities at 278 nm, calculated on the dried basis, do not differ by more than 3.0%.
Melting range 741: between 147 and 158, with slight darkening.
Loss on drying 731 Dry it at a pressure not exceeding 5 mm of mercury at 60 to constant weight: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.2%.
Ordinary impurities 466
Test solution: methanol.
Standard solution: methanol.
Eluant: a mixture of chloroform, methanol, and isopropylamine (94:3:3).
Visualization— Heat the plate in an oven at 105 for 15 minutes, cool, follow with visualization technique 17, and view under short-wavelength UV light.
Assay— Dissolve about 500 mg of Pentazocine, accurately weighed, in 50 mL of glacial acetic acid, add 1 drop of crystal violet TS, and titrate with 0.1 N perchloric acid VS to a green endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 28.54 mg of C19H27NO.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Clydewyn M. Anthony, Ph.D.
(MDCCA05) Monograph Development-Cough Cold and Analgesics
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 3243