title: Absorption of clonazepam after intranasal and buccal administration.
abstract: Serum concentrations of clonazepam after intranasal, buccal and intravenous administration were compared in a cross-over study in seven healthy male volunteers. Each subject received a 1.0 mg dose of clonazepam intranasally and buccally and 0.5 mg intravenously. A Cmax of 6.3 +/- 1.0 ng ml-1 (mean; +/- s.d.) was measured 17.5 min (median) (range 15-20 min) after intranasal administration. A second peak (4.6 +/- 1.3 ng ml-1) caused by oral absorption was seen after 1.7 h (range 0.7-3.0 h). After buccal administration a Cmax of 6.0 +/- 3.0 ng ml-1 was measured after 50 min (range 30-90 min) with a second peak of 6.5 +/- 2.5 ng ml-1 after 3.0 h (range 2.0-4.0 h). Two minutes after i.v. injection of 0.5 mg clonazepam the serum concentration was 27 +/- 18 ng ml-1. It is concluded that intranasal clonazepam is an alternative to buccal administration. However, the Cmax of clonazepam after intranasal administration is not high enough to recommend the intranasal route as an alternative to intravenous injection.
authors.affiliation: Department of Clinical Pharmacy and Toxicology, Maasland Hospital, Sittard, The Netherlands.
authors.forename: M W
authors.initials: MW
authors.lastname: Schols-Hendriks
authors.forename: J J
authors.initials: JJ
authors.lastname: Lohman
authors.forename: R
authors.initials: R
authors.lastname: Janknegt
authors.forename: J J
authors.initials: JJ
authors.lastname: Korten
authors.forename: F W
authors.initials: FW
authors.lastname: Merkus
authors.forename: P M
authors.initials: PM
authors.lastname: Hooymans
mesh_terms: D000042:Absorption; D000278:Administration, Buccal; D000281:Administration, Intranasal; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D002998:Clonazepam / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged
chemical_list: D002998:Clonazepam