Method for preparing eye drops of cyclosporin a

A method of preparing an eye drop formulation without preservatives, comprising:

• a) eliminating at least 99 wt % of ethanol contained in an oily solution, said oily solution comprising cyclosporine A, the ethanol, and polyoxyethylene castor oil, under a flow of nitrogen, under a pressure of 0.5 bar, at a temperature of from 2° C. to 45° C., and for a time period of 14 h to 24 h to form a concentrate of cyclosporine A in the oily solution,
• b) diluting the concentrate of cyclosporine A in the oily solution obtained in step a) in an aqueous solution,
• c) mix under stirring the concentrated oily solution obtained in step a) with the aqueous solution obtained in step b), at a temperature of between 2° C. and 45° C. for a period of from 0.05 h to 48 h to obtain a micellar solution having colloidal micelles less than 25 nm in size, and
• d) sterily packaging the micellar solution obtained in step c) for use as the eye drop formulation in packaging that is suitable for ophthalmic use.