title: Use of fibrin sealants for the localized, controlled release of cefazolin.
abstract: BACKGROUND
  Fibrin sealants are used increasingly in surgery to reduce bleeding and improve wound healing. They have great potential as biocompatible, biodegradable drug delivery systems, because the sealant may adhere to the target tissue and allow controlled release of the drug over an extended period. We investigated the encapsulation, stability and controlled release of erythromycin and cefazolin from Beriplast fibrin sealants (Aventis Behring Canada).
  
  
  METHODS
  Drug-loaded clots were cast in glass vials and allowed to set. We observed the clots for drug precipitation and aggregation, and we assessed the effect of drug encapsulation on clot strength. Drug stability and release from the clots in phosphate buffered saline (PBS) was quantified by ultraviolet and visible violet absorbance spectroscopy and high-performance liquid chromatography.
  
  
  RESULTS
  Erythromycin was found to release slowly from the fibrin clots over the first 2 hours but then degrade rapidly. Cefazolin was found to be very stable in clots in PBS (97% stable at 2 d and 93% stable at 5 d). The drug released in a controlled manner over 2 days, with most being released during the first day. The dose of drug released could be varied by changing the amount placed in the thrombin solution. Clot thickness had no effect on the rate of cefazolin release.
  
  
  CONCLUSIONS
  Overall, the 2-day release profile and the excellent stability of the drug suggest that cefazolin-loaded fibrin sealants may offer an effective route of postoperative antibiotic delivery.
authors.affiliation: Department of Pediatric Orthopedics, BC Children's Hospital, Vancouver, BC. stredwell@cw.bc.ca
authors.forename: Stephen
authors.initials: S
authors.lastname: Tredwell
authors.forename: John K
authors.initials: JK
authors.lastname: Jackson
authors.forename: Donald
authors.initials: D
authors.lastname: Hamilton
authors.forename: Vivian
authors.initials: V
authors.lastname: Lee
authors.forename: Helen M
authors.initials: HM
authors.lastname: Burt
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002437:Cefazolin / Q000032:analysis*; D003692:Delayed-Action Preparations / Q000032:analysis; D015718:Fibrin Tissue Adhesive / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D013057:Spectrum Analysis
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D015718:Fibrin Tissue Adhesive; D002437:Cefazolin