title: In vitro elution of amikacin and ticarcillin from a resorbable, self-setting, fiber reinforced calcium phosphate cement.
abstract: OBJECTIVE
  To determine in vitro elution characteristics of amikacin and ticarcillin from fiber reinforced calcium phosphate beads (FRCP).
  
  
  METHODS
  Experimental.
  
  
  METHODS
  FRCP beads with water (A), amikacin (B), ticarcillin/clavulanate (C), or both amikacin and ticarcillin/clavulanate (D) were bathed in mL phosphate-buffered saline (PBS) at 37°C, 5% CO(2) and 95% room air. PBS was sampled (eluent) and beads were placed in fresh PBS at time points 1 and 8 hours and 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 18, 21, 25, 28, 35, 42, 49, and 56 days. Antibiotic concentration and antimicrobial activity of eluent against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae were determined.
  
  
  RESULTS
  Both antibiotics eluted in a bimodal pattern. Beads with a single antibiotic eluted 20.8 ± 2.5% of amikacin and 29.5 ± 0.8% of ticarcillin over 56 days. Coelution of the antibiotics resulted in a lower proportion (AUC(0-∞) ) of antibiotics eluted for both amikacin (9.5 ± 0.2%) and ticarcillin (21.7 ± 0.09%). Bioassay of antimicrobial activity of the eluent (t = 1, 8, and 24 hours) established reduced antimicrobial activity of amikacin from combination beads (D).
  
  
  CONCLUSIONS
  FRCP beads with amikacin or ticarcillin/clavulanate, but not the combination, are suitable carriers for wound implantation.
  
  
  CONCLUSIONS
  Duration before complete resorption of FRCP beads in vivo should be determined before clinical use as a resorbable depot. The results of this study underscore the importance of testing drug combinations, despite success of the combination systemically, before their use in local applications.
authors.affiliation: Comparative Orthopaedics Laboratory, Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Ashlee E
authors.initials: AE
authors.lastname: Watts
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Nixon
authors.forename: Mark G
authors.initials: MG
authors.lastname: Papich
authors.forename: Holly D
authors.initials: HD
authors.lastname: Sparks
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Schwark
mesh_terms: D020341:Absorbable Implants; D000583:Amikacin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D001843:Bone Cements; D002130:Calcium Phosphates; D052978:Disk Diffusion Antimicrobial Tests; D004337:Drug Carriers; D004338:Drug Combinations; D004926:Escherichia coli / Q000187:drug effects; D066298:In Vitro Techniques; D007711:Klebsiella pneumoniae / Q000187:drug effects; D011098:Polyglactin 910; D013211:Staphylococcus aureus / Q000187:drug effects; D013982:Ticarcillin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D002130:Calcium Phosphates; D004337:Drug Carriers; D004338:Drug Combinations; D011098:Polyglactin 910; D000583:Amikacin; C020243:calcium phosphate; D013982:Ticarcillin