title: Excipients of preservative-free latanoprost induced inflammatory response and cytotoxicity in immortalized human HCE-2 corneal epithelial cells.
abstract: Various preservative-free eye drop formulations for glaucoma treatment have been marketed intending to decrease ocular surface side effects and improve tolerability. However, preservative-free eye drops including different solubilizers to dissolve the antiglaucoma drugs may induce detrimental effects in the eye. In this study, we exposed human corneal epithelial cells (HCE-2) for 1, 6, 12, 24 and 48 hours to the first preservative-free (PF) tafluprost (Taflotan®), the recently-launched preservative-free (PF) latanoprost (Monoprost®), preservative benzalkonium chloride (BAK) and the excipient macrogolglycerol hydroxystearate 40 (MGHS40) using dilutions 0.1%, 0.3%, 1.0%, 3.0% and 10.0% of the original products. The cells also were exposed to undiluted PF tafluprost and PF latanoprost once a day for 9 days. Cellular morphology was examined by light microscopy and cell proliferation by Ki-67 fluorescent staining with cell viability being determined by erythrosine staining and the release of lactate dehydrogenase (LDH). Mitochondrial metabolic activity was evaluated with the colorimetric MTT assay. The secretion of interleukin 6 (IL-6) was measured with ELISA. HCE-2 cells displayed no significant morphological changes after PF tafluprost treatment, but PF latanoprost caused clear cell loss. Moreover, PF latanoprost, BAK and MGHS40 evoked cellular damage and inflammation with increasing concentrations and time. Furthermore, undiluted daily PF latanoprost application significantly increased LDH release and IL-6 secretion as compared to PF tafluprost. MGHS40 was observed to be associated with the toxicity of PF latanoprost. Excipients in ocular drops should receive more attention in the future, since they seem to trigger similar detrimental effects in cells as preservatives.
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland ; Department of Physiology, Medical University of Silesia, Medykow 18, 40-752 Katowice, Poland ; Department of Ophthalmology, Division of Medicine and Dentistry in Zabrze, Medical University of Silesia, Panewnicka 65, 40-760 Katowice, Poland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Smedowski
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland ; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, 70210 Kuopio, Finland.
authors.forename: Jussi J
authors.initials: JJ
authors.lastname: Paterno
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland.
authors.forename: Elisa
authors.initials: E
authors.lastname: Toropainen
authors.affiliation: Wilmer Eye Institute; Johns Hopkins University School of Medicine, Baltimore, MD USA.
authors.forename: Debasish
authors.initials: D
authors.lastname: Sinha
authors.affiliation: Department of Ophthalmology, Division of Medicine and Dentistry in Zabrze, Medical University of Silesia, Panewnicka 65, 40-760 Katowice, Poland.
authors.forename: Edward
authors.initials: E
authors.lastname: Wylegala
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland ; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, 70210 Kuopio, Finland.
authors.forename: Kai
authors.initials: K
authors.lastname: Kaarniranta
keywords: cornea; cytotoxicity; drug; excipient; glaucoma; inflammation; preservative