Ropivacaine HCl is a member of the amino amide class of local anesthetics. Ropivacaine Hydrochloride Injection, USP is a sterile, isotonic solution that contains the enantiomerically pure drug substance, sodium chloride for isotonicity and water for injection. Sodium hydroxide and/or hydrochloric acid may be used for pH adjustment. It is administered parenterally.
Ropivacaine HCl is chemically described as S-(-)-1-propyl-2',6'-pipecoloxylidide hydrochloride monohydrate. The drug substance is a white crystalline powder, with a molecular formula of C17H26N2O•HCl•H2O, molecular weight of 328.89 and the following structural formula:
At 25°C ropivacaine HCl has a solubility of 53.8 mg/mL in water, a distribution ratio between n-octanol and phosphate buffer at pH 7.4 of 14:1 and a pKa of 8.07 in 0.1 M KCl solution. The pKa of ropivacaine is approximately the same as bupivacaine (8.1) and is similar to that of mepivacaine (7.7). However, ropivacaine has an intermediate degree of lipid solubility compared to bupivacaine and mepivacaine.
Ropivacaine Hydrochloride Injection, USP is preservative-free and is available in single-dose containers in 2 mg/mL (0.2%), 5 mg/mL (0.5%), 7.5 mg/mL (0.75%) and 10 mg/mL (1%) concentrations. The specific gravity of Ropivacaine Hydrochloride Injection, USP solutions range from 1.002 to 1.005 at 25°C.