Purchase this article with an account.
Haixia Liu, Ashley Nguyen, Jaya Giyanani, Joseph Glennon Vehige; Organic Osmolytes as Osmotic Agents vs. Salts in Artificial Tears. Invest. Ophthalmol. Vis. Sci. 2018;59(9):4912.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Two classes of osmotic agents are usually used in artificial tear formulations, salts and organic osmolytes (OO). Excessive salt is the cause of tear hyperosmolarity and has been shown to be inflammatory, which leads to epithelial cell damage. OO, such as glycerin, L-carnitine and erythritol are considered a beneficial replacement for salt due to their osmoprotectant effects and have been demonstrated to protect cells against hyperosmotic stress. The purpose of this study was to compare a series of marketed artificial tear products and their salt osmolality (SO) Vs. OO to differentiate the osmotic agents used in the formulations.
Ten marketed tear products were measured in the study both by Freezing Point Depression (FPD, Advanced Instruments Inc. Model 2020 Osmometer) for totally osmolality and Electrical Conductivity (EC, YSI 3200 Conductivity Meter) methods for SO. The tested products included the Allergan Optive family (Optive, Optive Gel Drops, Optive Fusion), Allergan Refresh family (Refresh Tears, Refresh Liquigel), Alcon Systane Ultra, Clear eyes PF Pure Relief, Advance Vision Thera Tears, J&J Visine Tears and AMO Blink Tears. All measurements followed the measurement procedure instructed by the manual of each instrument. Each measurement was repeated three times and the average was used for data analysis.
The OO of the tested products ranged from 47 to 255 mOsm/kg, with the highest in the Optive family (ranging from 246 to 255mOsm/kg), due to combinations of beneficial OO, such as glycerin, l-carnitine and erythritol. Systane Ultra and Visine Tears are also in the higher range of OO (187 and159 mOsm/kg respectively) due to the usage of propylene glycol. The osmotic balance of the remaining products is composed mostly of salt, with low OO content (range from 47 to 107mOsm/kg). The SO of the tested products ranged from 64 to 175 mOsm/kg, with the lowest in Blink tears (64 mOsm/kg) and the Optive family (ranging from 68 to 84 mOsm/kg).
Conclusions: Osmolalities are not created equal. Two classes of osmotic agents play different roles in the artificial tear formulations. This study verified that the osmotic balance of the Optive family is mainly composed of beneficial organic osmolytes (OO), specifically osmoprotectants, and is low in salt SO.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only