A sterilization process of timolol gel forming solution through aseptic filtration

A process for preparing a sterile ophthalmic composition, the process comprising:

• a) Collecting the hot water in a manufacturing vessel at a temperature of about 40° C. to about 60° C., preferably about 50° C.;
• b) Preparing a solution by adding and dissolving Mannitol, Tromethamine, Timolol Maleate, Benzododecinium Bromide and Gellan Gum under continuous stirring and make up the volume to 100%;
• c) Heating the solution of step (b) at temperature of about 100° C. to about 121° C. by passing steam through the jacket of manufacturing vessel for a period of about 1 hrs to 3 hrs to reduce the viscosity of solution to the desired range;
• d) Cooling down the solution of step (c) to room temperature (25±5° C.);
• e) Increasing the temperature of the solution of step (d) to about 60° C. to about 75° C. to obtain a viscous solution and
• f) Aseptically filter the viscous solution of step (e) through a 0.45 μm clarification filter (pre-filter) followed by a 0.2μ sterilizing grade filter for the sterilization of the bulk solution;
• g) the filtered solution is aseptically filled into 3-piece vials.