Zero-Order Antibiotic Release from Multilayer Contact Lenses: Nonuniform Drug and Diffusivity Distributions Produce Constant-Rate Drug Delivery.
A novel approach to zero-order constant-rate drug delivery from contact lenses is presented. Quasi-Case II non-Fickian transport is achieved by nonuniform drug and diffusivity distributions within three-layer bimodal amphiphilic conetworks (β-APCNs). The center layer is a highly oxygen permeable β-APCN matrix, which contains the drug and exhibits a high drug diffusivity. The outer β-APCN layers contain no-drug and are loaded with vitamin E, which slows diffusion. In contrast to single-layer neat-polymer and vitamin E-loaded films that display first-order "burst" kinetics, it is demonstrated experimentally and by modeling that the combined effect of nonuniform distribution of drug loading and diffusion constants within the three-layer lens maintains low local drug concentration at the lens-fluid interface and yields zero-order drug delivery. The release rates of topical antibiotics provide constant-rate therapeutic-level delivery with appropriate oxygen permeability for at least 30 h, at which time ≈25% of the drug was released.
Polymer Engineering Department, The University of Akron, Akron, OH, 44325, USA.
Gustavo
G
Guzman
Polymer Engineering Department, The University of Akron, Akron, OH, 44325, USA.
Siamak Shams
SS
Es-Haghi
Chemistry Department, Polymer Research Center, Boğaziçi University, 34342, Bebek, Istanbul, Turkey.
Turgut
T
Nugay
Polymer Engineering Department, The University of Akron, Akron, OH, 44325, USA.
Mukerrem
M
Cakmak
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D003263:Contact Lenses, Hydrophilic; D016503:Drug Delivery Systems / Q000379:methods*; D008956:Models, Chemical; D014810:Vitamin E / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D014810:Vitamin E
amphiphilic conetworks; contact lenses; drug release; zero-order