Nalmefene Hydrochloride Injectionrx Onlydescription
Nalmefene Hydrochloride Injection, an opioid antagonist, is a 6-methylene analogue of naltrexone. The chemical structure is shown below:
Molecular Formula: C21H25NO3•HCl•H2O
Molecular Weight: 393.91, CAS # 1228646-72-7
Chemical Name: 17-(Cyclopropylmethyl)-4,5α-epoxy-6-methylenemorphinan-3,14-diol, hydrochloride salt, monohydrate
Nalmefene hydrochloride is a white to almost white crystalline powder which is freely soluble in water up to 130 mg/mL and slightly soluble in chloroform up to 0.13 mg/mL, with a pKa of 7.6.
Nalmefene Hydrochloride Injection is available as a sterile solution for intravenous, intramuscular, and subcutaneous administration in two concentrations, containing 100 µg or 1.0 mg of nalmefene free base per mL. The 100 µg/mL concentration contains 110.8 µg of nalmefene hydrochloride and the 1.0 mg/mL concentration contains 1.108 mg of nalmefene hydrochloride per mL. Both concentrations contain 9.0 mg of sodium chloride per mL and the pH is adjusted in the range of 3.3-3.5 with hydrochloric acid.
Concentrations and dosages of Nalmefene Hydrochloride Injection are expressed as the free base equivalent of nalmefene.