title: Modeling vancomycin release kinetics from microporous calcium phosphate ceramics comparing static and dynamic immersion conditions.
abstract: The release kinetics of vancomycin from calcium phosphate dihydrate (brushite) matrices and polymer/brushite composites were compared using different fluid replacement regimes, a regular replacement (static conditions) and a continuous flow technique (dynamic conditions). The use of a constantly refreshed flowing resulted in a faster drug release due to a constantly high diffusion gradient between drug loaded matrix and the eluting medium. Drug release was modeled using the Weibull, Peppas and Higuchi equations. The results showed that drug liberation was diffusion controlled for the ceramics matrices, whereas ceramics/polymer composites led to a mixed diffusion and degradation controlled release mechanism. The continuous flow technique was for these materials responsible for a faster release due to an accelerated polymer degradation rate compared with the regular fluid replacement technique.
authors.affiliation: Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, D-97070 Würzburg, Germany. uwe.gbureck@fmz.uni-wuerzburg.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
authors.forename: Elke
authors.initials: E
authors.lastname: Vorndran
authors.forename: Jake E
authors.initials: JE
authors.lastname: Barralet
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D004353:Drug Evaluation, Preclinical; D004343:Drug Implants / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D016062:Porosity; D014640:Vancomycin / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D004343:Drug Implants; D014640:Vancomycin; C020243:calcium phosphate