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Substance Name: Chlorzoxazone [USP:INN:BAN:JAN]
RN: 95-25-0
UNII: H0DE420U8G
InChIKey: TZFWDZFKRBELIQ-UHFFFAOYSA-N

Note

  • A centrally acting central muscle relaxant with sedative properties. It is claimed to inhibit muscle spasm by exerting an effect primarily at the level of the spinal cord and subcortical areas of the brain. (From Martindale, The Extra Pharmacopoea, 30th ed, p1202)

Molecular Formula

  • C7-H4-Cl-N-O2

Molecular Weight

  • 169.5666
 

Classification Codes

  • Central Nervous System Agents
  • Drug / Therapeutic Agent
  • Human Data
  • Muscle Relaxants, Central
  • Neuromuscular Agents
  • Peripheral Nervous System Agents
  • Relaxant (Skeletal Muscle)

Names and Synonyms

Name of Substance

  • Chlorzoxazone
  • Chlorzoxazone [USP:INN:BAN:JAN]

MeSH Heading

  • Chlorzoxazone

Synonyms

  • 2-Hydroxy-5-chlorobenzoxazole
  • 5-Chlorbenzoxazolin-2-on
  • 5-Chloro-2-benzoxazolinone
  • 5-Chloro-2-benzoxazolol
  • 5-Chloro-2-hydroxybenzoxazole
  • 5-Chloro-3(H)-2-benzoxazolone
  • 5-Chlorobenzoksazolinon-2
  • 5-Chlorobenzoksazolinon-2 [Polish]
  • 5-Chlorobenzoksazolon-2
  • 5-Chlorobenzoksazolon-2 [Polish]
  • 5-Chlorobenzoxazol-2-one
  • 5-Chlorobenzoxazolidone
  • 5-Chlorobenzoxazolone
  • 6-Chloro-2-benzoxazolinone
  • AI3-63119
  • Biomioran
  • Chloroxazone
  • Chlorsoxazone
  • Chlorzoxazon
  • Chlorzoxazone
  • Chlorzoxazonum
  • Chlorzoxazonum [INN-Latin]
  • Clorzoxazona
  • Clorzoxazona [INN-Spanish]
  • EINECS 202-403-9
  • Escoflex
  • Klorzoxazon
  • Lorzone
  • Mioran
  • Miotran
  • Myoflexin
  • Myoflexine
  • Neoflex
  • NSC 26189
  • Nyoflex
  • Paraflex
  • Parafon
  • Parafon Forte
  • Parafon Forte DSC
  • Pathorysin
  • Remofleks
  • Solaxin
  • Strifon
  • Strifon Forte DSC
  • UNII-H0DE420U8G
  • USAF MA-10

Systematic Names

  • 2(3H)-Benzoxazolone, 5-chloro-
  • 2-Benzoxazolinone, 5-chloro-
  • Chlorzoxazone

Registry Numbers

CAS Registry Number

  • 95-25-0

FDA UNII

  • H0DE420U8G

Other Registry Number

  • 32850-84-3

System Generated Number

  • 0000095250

Structure Descriptors

InChI

1S/C7H4ClNO2/c8-4-1-2-6-5(3-4)9-7(10)11-6/h1-3H,(H,9,10)

InChIKey

TZFWDZFKRBELIQ-UHFFFAOYSA-N

Smiles

c1cc2c(cc1Cl)nc(o2)O

Toxicity

Organism Test Type Route Reported Dose (Normalized Dose) Effect Source
hamster LD50 intraperitoneal 166mg/kg (166mg/kg) BEHAVIORAL: ATAXIA

BEHAVIORAL: MUSCLE WEAKNESS

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)		 Journal of Pharmacology and Experimental Therapeutics. Vol. 129, Pg. 75, 1960.
hamster LD50 oral 662mg/kg (662mg/kg) BEHAVIORAL: MUSCLE WEAKNESS

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)

BEHAVIORAL: ATAXIA		 Journal of Pharmacology and Experimental Therapeutics. Vol. 129, Pg. 75, 1960.
mammal (species unspecified) LD50 intraperitoneal 550mg/kg (550mg/kg) BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX) Chimica Therapeutica. Vol. 6, Pg. 65, 1971.
man TDLo oral 50mg/kg (50mg/kg) BEHAVIORAL: COMA

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)		 American Journal of Emergency Medicine. Vol. 16, Pg. 393, 1998.
mouse LD50 intraperitoneal 50mg/kg (50mg/kg)   National Technical Information Service. Vol. AD277-689,
mouse LD50 oral 440mg/kg (440mg/kg)   Arzneimittel-Forschung. Drug Research. Vol. 17, Pg. 242, 1967.
mouse LD50 subcutaneous 170mg/kg (170mg/kg) BEHAVIORAL: ANTICONVULSANT Acta Pharmacologica et Toxicologica. Vol. 19, Pg. 247, 1962.
rat LD50 intraperitoneal 150mg/kg (150mg/kg) BEHAVIORAL: MUSCLE WEAKNESS

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)

BEHAVIORAL: ATAXIA		 Journal of Pharmacology and Experimental Therapeutics. Vol. 129, Pg. 75, 1960.
rat LD50 oral 763mg/kg (763mg/kg) BEHAVIORAL: ATAXIA

BEHAVIORAL: MUSCLE WEAKNESS

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)		 Journal of Pharmacology and Experimental Therapeutics. Vol. 129, Pg. 75, 1960.

Physical Properties

Physical Property Value Units Temp (deg C) Source
Melting Point 191.5 deg C   EXP
log P (octanol-water) 1.590 (none)   EST
Atmospheric OH Rate Constant 2.20E-11 cm3/molecule-sec 25 EST

Physical property data is provided to ChemIDplus by SRC, Inc.