title: In vitro - in vivo evaluation of a new oral dosage form of tramadol hydrochloride--controlled-release capsules filled with coated pellets.
abstract: The aim of this study was an in vitro - in vivo evaluation of a new oral dosage form of tramadol hydrochloride (TH), controlled-release capsules filled with coated pellets, 100 mg (TC), compared to the sustained release tablets, Tramal Retard, 100 mg (TR). In vitro release study of both formulations showed a similar release profile of TH over 8 h (f2 was 52). In vivo study (single oral, 100 mg dose administration in 8 rabbits) showed that the amount of TH absorbed into the systemic circulation after TC and TR administration was also similar (90% CI for AUC(0-t) and AUC(0-infinity) were 90-124% and 97-109%, respectively). However, a comparison of AUC(0-t) of pharmacokinetics of TC and TR indicates significantly prolonged absorption and elimination processes of TH when the drug is given in controlled-release capsules filled with coated pellets. It was manifested by longer: mean absorption time (p = 0.0016), mean residence time (p = 0.0268), absorption half-life (p = 0.0016), elimination half-life (p = 0.0493) and lower: absorption rate constant (p = 0.0016), elimination rate constant (p = 0.0148) and total body clearance Cl/F (p = 0.0076). It may be concluded that the new TH formulation could be expected to have a more prolonged analgesic activity than commercial sustained release tablets.
authors.forename: Danuta
authors.initials: D
authors.lastname: Szkutnik-Fiedler
authors.forename: Monika
authors.initials: M
authors.lastname: Balcerkiewicz
authors.forename: Wiesław
authors.initials: W
authors.lastname: Sawicki
authors.forename: Tomasz
authors.initials: T
authors.lastname: Grabowski
authors.forename: Edmund
authors.initials: E
authors.lastname: Grześkowiak
authors.forename: Jarosław
authors.initials: J
authors.lastname: Mazgalski
authors.forename: Hanna
authors.initials: H
authors.lastname: Urjasz
mesh_terms: D000284:Administration, Oral; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D019540:Area Under Curve; D002214:Capsules; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D006207:Half-Life; D007408:Intestinal Absorption; D008657:Metabolic Clearance Rate; D011817:Rabbits; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods; D014147:Tramadol / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D000701:Analgesics, Opioid; D002214:Capsules; D003692:Delayed-Action Preparations; D014147:Tramadol