title: Corticosteroid-releasing cochlear implant: a novel hybrid of biomaterial and drug delivery system.
abstract: In this study, drug-eluting cochlear implant (CI) electrodes were prepared, and the amount of drug released was determined. Dexamethasone (DEX) (0.25-2% w/w, the weight percent of the final cured polymer) was used as a bioactive agent to suppress postsurgical inflammations upon mixing with a two-part nonrestricted pourable medical-grade silicone elastomer. Batch reproducibility analysis was performed on three consecutive batches. Drug release experiments were accomplished in normal saline medium, where DEX was analyzed via a validated HPLC method. The drug loading percentage and the device surface area were the most dominant parameters explored to monitor the drug release behavior from CI coatings. Total cumulative amount of DEX released from various loaded samples was in the order of 2 > 1 > 0.5 > 0.35 > 0.25% w/w, but the cumulative percentage of drug released showed a reverse order. The DEX dosages between 0.1 and 1 microg were released from samples of smallest to highest loadings during the initial 24 h, and dosages <1-5 microg were released from similar samples of various loadings at the first patency 2 weeks. The extent of crosslinking was only effective on release profile at lower drug loadings of 0.25% w/w relative to 0.5%. It was also found that release profile was not affected by postcuring. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
authors.affiliation: Department of Novel Drug Delivery Systems, Iran Polymer and Petrochemical Institute, 14965/115 Tehran, Iran.
authors.forename: Farhid
authors.initials: F
authors.lastname: Farahmand Ghavi
authors.affiliation: Department of Biomaterials, Iran Polymer and Petrochemical Institute, 14965/115 Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Mirzadeh
authors.affiliation: Department of Novel Drug Delivery Systems, Iran Polymer and Petrochemical Institute, 14965/115 Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Imani
authors.affiliation: Electrode Research Section, MED-EL Company, Innsbruck, Austria.
authors.forename: Claude
authors.initials: C
authors.lastname: Jolly
authors.affiliation: Ear/Nose/Throat- Head & Neck Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Farhadi
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D001672:Biocompatible Materials; D019929:Cochlear Implantation / Q000009:adverse effects; D003054:Cochlear Implants; D003907:Dexamethasone / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods*; D004566:Electrodes; D007249:Inflammation / Q000517:prevention & control; D008954:Models, Biological; D012965:Sodium Chloride
chemical_list: D000305:Adrenal Cortex Hormones; D001672:Biocompatible Materials; D012965:Sodium Chloride; D003907:Dexamethasone