Eyeworld

EW NEWS & OPINION September 2017 25 Timoptic and Ocudose are trademarks of Valeant Pharmaceuticals International, Inc. or its aliates. ISTALOL is a registered trademark of Bausch & Lomb Incorporated or its aliates. © 2016 Bausch & Lomb Incorporated. TOP.0024.USA.16 Timoptic and Ocudose are trademarks of Valeant Pharmaceuticals International, Inc. or its aliates. ISTALOL is a registered trademark of Bausch & Lomb Incorporated or its aliates. S:6.69" T:7.19" B:7.44" by Liz Hillman EyeWorld Staff Writer different preservatives in five brands of over-the-counter artificial tears. 4 The brand that contained BAK was sterilization purposes—is now the most frequently used preservative in ophthalmic solutions to prevent contamination. 2,3 A study published in Cornea evaluated efficacy of tion could be due to the design of the bottle and patient instillation technique. 1 BAK—among the first preser- vatives to be added to eye drops for TearClear begins work to bring BAK-filtering hydrogel to drop market W hen it comes to eye drops, ophthalmol- ogists—and their patients—want to have their cake and eat it, too. That is, they want drops to be preservative-free when they reach the eye but remain sterile (pre- served) in a multi-dose bottle. "What we would all like when the drop hits the eye is that it not be preserved, but in the bottle, we want it to be preserved," said Richard Lindstrom, MD, adjunct professor emeritus, Department of Ophthal- mology, University of Minnesota, and Minnesota Eye Consultants, Minneapolis. He said that the most common preservative for ophthal- mic drops is benzalkonium chloride (BAK), which is well-known for its ocular side effects. "The way that's been handled in the past is we've had tiny, single-dose vials with a non-preserved solution with one or two drops in them. It's inconvenient for the patient, somewhat awkward to deliver, and significantly more expensive. What we'd like is to have a larger bottle holding hundreds of drops, 5 to 10 ml of solution." TearClear (Orange County, Cal- ifornia), an eye health technology company, earlier this year licensed and secured $4.5 million in financ- ing for a chemical filter that Dr. Lindstrom, a member of TearClear's medical advisory board and board of directors, said is fit inside a drop bot- tle to strain BAK out of the drop as it comes out of the tip while allowing the drug's active ingredients to pass through onto the eye unaltered. The chemical filter is a pro- prietary hydrogel created by Anuj Chauhan, PhD, at the University of Florida. As TearClear describes it, the filter is "a plug of microparticles of polymeric gels that display hydraulic permeability." Why preserve? Research published in the British Journal of Ophthalmology described a "high incidence (8.4%) of microbial contamination" in preservative-free multi-dose eye drop bottles ana- lyzed in the study. The authors of this study stated that contamina- Eye drops preserved in the bottle and preservative-free out? continued on page 26

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