Enzymatic hydrolysis assay
The liposome/OMC formulation was not hydrolyzed by
lipase in the enzymatic hydrolysis assay. This was probably
due to the arrangement of phosphatidylcholine in the liposome
bilayer. The phosphatidylcholine fatty acid moieties
are turned towards the inner side of the vesicles, preventing
enzymatic hydrolysis of the ester groups. Therefore, it can
be concluded that the liposome is capable of protecting the
filter against the lipase enzymatic degradation caused by
lipases present in the stratum corneum, thereby increasing
the residence time of the vesicle on the skin.39,