title: Diffusion of rat atrial natriuretic factor in thermoreversible poloxamer gels.
abstract: Concentrated poloxamer 407 solutions display a negative thermorheological behaviour, resulting in a higher viscosity at body temperature than below. This could be exploited for various controlled delivery applications including the nasal delivery of peptides. The rheology of the gel and the diffusion of ANF were studied as a function of temperature. A theory is proposed, according to which a temperature rise creates an intermicellar network resulting in a viscosity increase. The diffusion of the drug appears limited only by the presence of micelles which lengthens the diffusion pathways and is not significantly influenced by the formation of this network.
authors.affiliation: Faculté de Pharmacie, Université de Montréal, Québec, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Juhasz
authors.forename: V
authors.initials: V
authors.lastname: Lenaerts
authors.forename: P
authors.initials: P
authors.lastname: Raymond
authors.forename: H
authors.initials: H
authors.lastname: Ong
mesh_terms: D009320:Atrial Natriuretic Factor / Q000008:administration & dosage; D004058:Diffusion; D004337:Drug Carriers; D005782:Gels; D008422:Materials Testing; D010455:Peptides / Q000008:administration & dosage*; D011060:Poloxalene; D011092:Polyethylene Glycols; D012212:Rheology; D013696:Temperature; D014783:Viscosity
chemical_list: D004337:Drug Carriers; D005782:Gels; D010455:Peptides; C472610:atrial natriuretic peptide, rat; D011092:Polyethylene Glycols; D009320:Atrial Natriuretic Factor; D011060:Poloxalene