title: Therapeutic contact lenses: a patent review.
abstract: BACKGROUND
  Ophthalmic drugs are almost exclusively delivered via eye drops in spite of several deficiencies, including low bioavailability and poor compliance. Contact lenses have the potential to increase bioavailability by an order of magnitude, while also improving compliance.
  
  
  METHODS
  In this review, the authors summarize advances in therapeutic contact lenses. The major focus of the review is on patents on drug-eluting contact lenses, but non-drug-eluting contacts that offer a therapeutic benefit are also included. The content is divided based on the broad technology of the patent, including novel materials, molecular imprinting, diffusion barriers, colloid encapsulation, surface modification, layering, and other novel approaches. In addition to patents, research publications are also included to facilitate the understanding of the mechanisms and challenges.
  
  
  CONCLUSIONS
  Among all non-invasive alternatives, contact lenses offer the highest bioavailability to the cornea due to the location of the lens in the immediate vicinity of the cornea. Several approaches have been patented to improve contact lens design for an extended release duration of drugs. Many technologies have successfully integrated suitable drug release profiles into contact lenses, but drug-eluting contacts are not yet commercialized likely due to regulatory challenges, including the high costs of clinical trials.
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Phillip
authors.initials: P
authors.lastname: Dixon
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Chancellor
authors.initials: C
authors.lastname: Shafor
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gause
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Kuan-Hui
authors.initials: KH
authors.lastname: Hsu
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Kristin Conrad
authors.initials: KC
authors.lastname: Powell
authors.affiliation: a University of Florida, Department of Chemical Engineering , 1006 Center Dr, Gainesville, FL 32611, USA +1 352 392 2592 ; +1 352 392 9513 ; chauhan@che.ufl.edu.
authors.forename: Anuj
authors.initials: A
authors.lastname: Chauhan
mesh_terms: D060433:Administration, Ophthalmic; D000818:Animals; D001682:Biological Availability; D003261:Contact Lenses; D003315:Cornea / Q000378:metabolism; D016503:Drug Delivery Systems; D015195:Drug Design; D006801:Humans; D055118:Medication Adherence; D010330:Patents as Topic
keywords: contact lens; drug delivery; imprinted lens; layered lens; nanoparticles; vitamin E