The tear film has been traditionally reported to consist of three important components: a mucin layer that coats the ocular surface epithelium, an aqueous layer that is present between the mucin and a lipid layer, and a lipid layer that overlays the surface of the tear film [ 7].
The presence of an aqueous layer and, consequently, of an interface between the aqueous and the vitreous substitute also has a crucial effect in the possible development of an emulsion, which is one of the main drawbacks associated with the use of silicon oils.
The tear film is composed of three layers: the external lipid layer, an aqueous layer and an internal mucin layer [ 9].
Each well in the resulting plate had two layers, with an aqueous layer at the bottom and a hydrophobic layer on top containing the lipid extract.
The aqueous layer was basified to pH 10 by the addition of concentrated NH4OH and was then resuspended in a mixture of CHCl3 and MeOH (3:1 v/v) (the total volume of CHCl3:MeOH is equal to four times the volume of the aqueous layer) to be later separated into an organic layer and an aqueous layer labelled as "I.3" and "I.4", respectively.
It is believed that the hydrophilic stationary phase enriches water from the buffer and thus generates an aqueous layer [ 17].
The precorneal tear film has traditionally been described as consisting of an outer lipid layer, a middle aqueous layer and an inner mucus layer.
Whereas, under alkaline condition, the alkaloids exist in free amine base form and can be solubilized into the acetonitrile layer but phase separation cannot be achieved between the aqueous layer containing the salt and the acetonitrile phase.
We now wish to study the stability of the interface between the aqueous layer and the vitreous substitute.
Model 3. Finally, we study the stability of the interface between the aqueous layer and the vitreous substitute, when the two fluids are set in motion by eye rotations.
