title: Methylprednisolone delivery to the back of the eye using hydrogel iontophoresis.
abstract: OBJECTIVE
  The aim of this study was to evaluate methylprednisolone penetration into ocular structures after low-current trans-scleral hydrogel iontophoresis, as compared with the common intravenous (i.v.) treatment.
  
  
  METHODS
  Methylprednisolone hemisuccinate (MPH) iontophoresis was studied in rabbits, using drug-loaded hydrogels mounted on a portable iontophoretic device. Cathodal iontophoresis of 2.6 mA/cm(2) was applied for 5 min at two opposite sites on the sclera or for 10 min at the same site. Ocular drug levels were determined 2 h after iontophoretic treatment, then compared to mock iontophoresis and i.v. infusion of 10 mg/kg methylprednisolone.
  
  
  RESULTS
  Significantly higher methylprednisolone levels were found in ocular tissues after iontophoresis, compared with the control groups, except for the sclera concentrations, which were similar to the concentrations achieved after mock iontophoresis. Two (2) h after the trans-scleral iontophoretic treatment, 178.59 +/- 21.63 microg/g, 6.74 +/- 2.38 microg/ml, and 2.71 +/- 0.57 microg/mL were found in the retina, aqueous humor, and vitreous, respectively. No significant differences were found between one or two site treatments of trans-scleral iontophoresis. Nondetectable concentrations were found 2 h after the i.v. infusion of 10 mg/kg of methylprednisolone in all evaluated ocular tissues and fluids.
  
  
  CONCLUSIONS
  A short, low-current noninvasive iontophoretic treatment, using methylprednisolone-loaded hydrogels, has potential clinical value in treating ocular inflammatory diseases.
authors.affiliation: Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: Esther
authors.initials: E
authors.lastname: Eljarrat-Binstock
authors.forename: Faik
authors.initials: F
authors.lastname: Orucov
authors.forename: Joseph
authors.initials: J
authors.lastname: Frucht-Pery
authors.forename: Jacob
authors.initials: J
authors.lastname: Pe'er
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Domb
mesh_terms: D000465:Algorithms; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D002851:Chromatography, High Pressure Liquid; D005123:Eye / Q000378:metabolism*; D020100:Hydrogels; D007262:Infusions, Intravenous; D007478:Iontophoresis; D008297:Male; D008689:Methacrylates; D008775:Methylprednisolone / Q000008:administration & dosage*; D011817:Rabbits; D012590:Sclera / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D020100:Hydrogels; D008689:Methacrylates; C005044:hydroxyethyl methacrylate; D008775:Methylprednisolone