Langmuir films study on lipid-containing artificial tears.

Lipid-containing artificial tears are a type of artificial tears that use lipid components in order to restore the lipid layer of the tear film. One of these components is lecithin which can be applied in spray solutions containing lecithin liposomes. In this work the behavior of three of these commercial tears based on lecithin, Innoxa, Opticalm and Optrex, are studied using the Langmuir technique. The obtained isotherms are presented, discussed and compared. This technique seems useful in order to see the film behavior of the lipid components of these tears and determine some important parameters such as fluidity and extension at the air-water interface, and allows us to discern differences between these commercial tears. Innoxa and Optrex tears are more similar to each other than to Opticalm tears. Opticalm presents more fluidity, probably due to the presence of more insaturations in the fatty acid chains of the phospholipids of the lecithin used in fabrication.