title: Differential penetration of ototopicals and water through tympanostomy tubes.
abstract: OBJECTIVE
  To evaluate the penetration of ototopicals and water through tympanostomy tubes (TT) using a physical model.
  
  
  METHODS
  An in vitro model was created to measure the ability of various solutions to penetrate a variety of TT.
  
  
  METHODS
  A TT was placed through a perforation (myringotomy) in a silastic sheet (tympanic membrane) fixed between the ends of two 1 mL syringes. Measurements were obtained of the maximum height various liquids (tap water, 2% soapy water, ocean water, ofloxacin otic, corticosporin otic, and ciprofloxacin/dexamethasone otic) achieved before penetrating different TTs (1.0 mm or 1.27 mm Paparella silicone, 1.14 mm or 1.27 mm Reuter Bobbin titanium, 1.27 mm Collar Button fluoroplastic or 1.14 mm T-type silicone).
  
  
  RESULTS
  Two percent soapy water was significantly more permeable than water and ocean water in all tubes studied. Ciprofloxacin/dexamethasone otic was significantly more permeable than tap water, ocean water, and ofloxacin otic in only the Collar Button fluoroplastic TT. Our results suggest that titanium TTs are more permeable than other TT. Otherwise, ototopicals, tap water, and ocean water behaved similarly across all TT studied.
  
  
  CONCLUSIONS
  Our results demonstrate that ototopicals, tap water, and ocean water behave similarly with regard to TT penetration. Ciprofloxacin/dexamethasone otic may have better penetration than other ototopicals. Titanium TT may be easier to penetrate than other TT.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Miami School of Medicine, Miami, FL 33136, U.S.A.
authors.forename: Lee P
authors.initials: LP
authors.lastname: Smith
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Smullen
authors.forename: Ramzi T
authors.initials: RT
authors.lastname: Younis
mesh_terms: D000287:Administration, Topical; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D004867:Equipment Design; D004869:Equipment Safety; D006801:Humans; D066298:In Vitro Techniques; D008876:Middle Ear Ventilation / Q000295:instrumentation*; D008954:Models, Biological; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014867:Water / Q000008:administration & dosage*
chemical_list: D000900:Anti-Bacterial Agents; D014867:Water