A drug-eluting contact lens
Joseph Bowers Ciolino 1,
Todd R Hoare 2,
Naomi G. Iwata 2,
Irmgard Behlau 3,
Claes H. Dohlman 4,
Robert Langer 2,
and
Daniel S Kohane 5*
1 Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States
2 Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
3 Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States; Harvard Medical School, The Schepens Eye Research Institute, Boston, Massachusetts, United States
4 Harvard Medical School, Massachusetts Eye & Ear Infirmary, Boston, Massachusetts, United States
5 Anesthesiology/Critical Care Medicine, Children's Hospital Boston, Bader 628, Boston, Massachusetts, 02115, United States
* To whom correspondence should be addressed. E-mail: daniel.kohane{at}childrens.harvard.edu.
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Abstract |
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Purpose: To formulate and characterize a drug-eluting contact lens designed to provide extended, controlled release of a drug.
Methods: Prototype contact lenses were created by coating PLGA (Poly[lactic-co-glycolic acid]) films containing test compounds with pHEMA (poly[hydroxyethyl methacrylate]) by ultraviolet light polymerization. The films, containing encapsulated fluorescein or ciprofloxacin, were characterized by scanning electron microscopy. Release studies were conducted in phosphate buffered saline at 37 degree Celsius with continuous shaking. Ciprofloxacin eluted from the contact lens was studied in an antimicrobial assay to verify antimicrobial effectiveness.
Results: After a brief and minimal initial burst, the prototype contact lenses demonstrated controlled release of the molecules studied, with zero-order release kinetics under infinite sink conditions for over 4 weeks. The rate of drug release was controlled by changing either the ratio of drug to PLGA or the molecular weight of the PLGA employed. Both the PLGA and the pHEMA affected release kinetics. Ciprofloxacin released from the contact lenses inhibited ciprofloxacin-sensitive Staphylococcus aureus at all time-points tested.
Conclusions: A prototype contact lens for sustained drug release consisting of a thin drug-PLGA film coated with pHEMA could potentially be used as a platform for ocular drug delivery with widespread therapeutic applications.
Key Words:
contact lenses, drug delivery, antibiotics
