title: Gelled calcium polyphosphate matrices delay antibiotic release.
abstract: Introducing a gelling step during antibiotic incorporation has previously been found to delay vancomycin delivery from a calcium polyphosphate matrix intended for local treatment of bone infections. This study examined the general applicability of this approach using cefuroxime, a lower-molecular-weight antibiotic with different charge characteristics compared with those of vancomycin. A calcium polyphosphate/cefuroxime paste was "gelled" in disk form in a humid environment for 5 or 24 hours prior to drying. Antibiotic release in Tris-buffered saline under gentle agitation was monitored over a seven-day period. While non-gelled samples clearly exhibited a burst release, the gelling process significantly retarded early antibiotic release from five- and 24-hour gelled matrices, yielding a constant release rate over the first four days. Cefuroxime incorporation did not appear to alter matrix structure or degradation. Overall, this non-aggressive process effectively trapped cefuroxime and reduced its release rate, suggesting its potential applicability with molecularly diverse therapeutic agents.
authors.affiliation: Department of Applied Oral Sciences, Faculty of Dentistry, Dalhousie University, 5981 University Avenue, Halifax, Nova Scotia B3H 3J5, Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: Schofield
authors.forename: B
authors.initials: B
authors.lastname: Berno
authors.forename: M
authors.initials: M
authors.lastname: Langman
authors.forename: G
authors.initials: G
authors.lastname: Hall
authors.forename: M J
authors.initials: MJ
authors.lastname: Filiaggi
mesh_terms: D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002130:Calcium Phosphates / Q000008:administration & dosage; D002444:Cefuroxime / Q000008:administration & dosage*; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D005782:Gels; D008826:Microbial Sensitivity Tests; D014677:Pharmaceutical Vehicles; D011122:Polyphosphates / Q000008:administration & dosage*; D013059:Spectrum Analysis, Raman; D013212:Staphylococcus epidermidis / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D003692:Delayed-Action Preparations; D005782:Gels; D014677:Pharmaceutical Vehicles; D011122:Polyphosphates; D002444:Cefuroxime