Pharmacokinetics, safety and tolerance of single- and multiple-dose of a novel compound tramadol hydrochloride injection (35 mg tramadol hydrochloride, 45 mgl promethazine hydrochloride) in Chinese healthy subjects.

The pharmacokinetics of Tramadol and Promethazine after a single dose of 40, 80 and 120 mg intramuscular injecting CTHI was evaluated in healthy volunteers. Physical exam, vital signs, clinical laboratory tests and electrocardiogram measurements were monitored to assess the safety and tolerance of the drug. The plasma levels of Tramadol and Promethazine in serial samples were measured by a validated HPLC-MS method. No subject showed any drug-related clinically significant changes on physical examination, vital signs or laboratory tests.