title: Bioequivalence study of tramadol by intramuscular administration in healthy volunteers.
abstract: Tramadol hydrochloride (CAS 36282-47-0) is a centrally acting analgesic agent binding to mu opiate receptors. The bioavailability of a new tramadol hydrochloride injection (Limadol) was compared with a commercially available reference product by intramuscular administration in twelve healthy Chinese male volunteers by a standard two-way cross-over trial. Each volunteer received a single 100 mg injection of tramadol HCl in each phase. The bioavailability was compared using the area under the plasma concentration-time curve from time 0 to 30 h (AUC0-30), the area under the plasma concentration-time curve from time 0 to infinity (AUC0-infinity), peak plasma concentration (Cmax), and time to reach peak plasma concentration (Tmax). No statistically significant difference was observed between the Tmax, Cmax, AUC0-30 and AUC0-infinity of the two preparations. It is concluded that test and reference formulations of tramadol hydrochloride are bioequivalent for both the extent and rate of absorption after a single intramuscular injection.
authors.affiliation: Department of Pharmaceutical Technology, Mithra Bioindustry Co., Taipei Hsien, Taiwan.
authors.forename: C K
authors.initials: CK
authors.lastname: Chao
authors.forename: L L
authors.initials: LL
authors.lastname: Yu
authors.forename: L L
authors.initials: LL
authors.lastname: Su
authors.forename: C M
authors.initials: CM
authors.lastname: Liu
authors.forename: T H
authors.initials: TH
authors.lastname: Yang
authors.forename: C M
authors.initials: CM
authors.lastname: Chen
mesh_terms: D000042:Absorption; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007273:Injections, Intramuscular; D008297:Male; D013810:Therapeutic Equivalency; D014147:Tramadol / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000701:Analgesics, Opioid; D007202:Indicators and Reagents; D014147:Tramadol