title: A continuous flow method for estimation of drug release rates from emulsion formulations.
abstract: We present a continuous-flow method that allows the release of drugs from submicron colloidal carriers to be estimated on a millisecond timescale. The technique is applied to the study of release of a model drug (tetracaine) from lipid emulsions, and shows that the solute drug is released in this timescale, and thus is primarily controlled by the rapid diffusion of the drug within the oil droplet. This confirms our previous claims that existing methods, such as dialysis or centrifugation, are too slow to provide useful release data for drug-containing emulsions, and demonstrates that it is unlikely that a simple emulsion could be used as a circulating sustained-release formulation, as has been suggested by some workers.
authors.affiliation: Pharmaceutical Development, AstraZeneca, Hurdsfield Road, Macclesfield, Cheshire SK10 2NA, UK. Electronic address: Lotta.salmela@astrazeneca.com.
authors.forename: Lotta
authors.initials: L
authors.lastname: Salmela
authors.affiliation: Pharmaceutical Development, AstraZeneca, Hurdsfield Road, Macclesfield, Cheshire SK10 2NA, UK. Electronic address: Clive.washington@astrazeneca.com.
authors.forename: Clive
authors.initials: C
authors.lastname: Washington
mesh_terms: D065546:Drug Liberation; D004655:Emulsions / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D054709:Lecithins / Q000737:chemistry; D013748:Tetracaine / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry
chemical_list: D004655:Emulsions; D054709:Lecithins; D014280:Triglycerides; D013748:Tetracaine
keywords: Colloid; Drug delivery; Drug release; Emulsion; Lecithin (PubChem CID: 57369748); Lipid; Tetracaine (PubChem CID: 5411); Triglyceride; Triglyceride oil (PubChem CID: 5460048)