In vitro release of CsA from different proliposomes and a commercial product Restasis® (Allergan) was evaluated by a dynamic dialysis method.7 (link),22 (link) SCF-EPCS and Film-EPCS were used for this study, and Restasis® was used as control to compare the release profiles of CsA from formulations. Before the release test, proliposomes were dispersed in Milli-Q water, and total CsA content present in the samples was analyzed using HPLC assay. Two microliters of each sample was sealed in dialysis bags (MWCO 14,000 Da; dialysis tubing cellulose membrane, Sigma-Aldrich) by tightening the two ends of the tube by a thin thread. Dialysis tubes were soaked in Milli-Q water 24 hours before use. Then the dialysis bags containing a sample were immersed in a vial containing 10 mL simulated lacrimal fluid (SLF), which was maintained in a water bath at 32°C, based on the temperature of the eye surface, and stirred at a rotating speed of 50 rpm. The composition of SLF was 8.3 g NaCl, 0.084 g CaCl2·2H2O, and 1.4 g KCl in 1 L Milli-Q water.23 (link) At time intervals of 0.5, 1, 2, 3, 4, 5, 6, and 24 hours, 1 mL of samples were withdrawn and immediately replaced with the equal volume of a fresh SLF solution. Withdrawn samples were then centrifuged and CsA contents were analyzed by the HPLC assay.