A process for the preparation of sterile topical ophthalmic aqueous nanosuspensions containing fluticasone propionate Form A nanocrystals having a mean particle size from 100 nm to 1000 nm and a concentration of fluticasone propionate from 0.001% w/w to 1% w/w, said process comprises: a) preparing an aqueous vehicle 1 containing: 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide IN to adjust the pH at 7.3 - 7.5 and water to 100% w/w; b) mixing an amount of fluticasone propionate Form A nanocrystals having a mean particle size from 100 nm to 1000 nm with an amount of aqueous vehicle 1 to obtain a slurry containing a concentration of fluticasone propionate of 2% w/w; c) applying high-shear, high-speed mixing to the slurry of step b) for at least 10 minutes; d) preparing an aqueous vehicle 2 containing: 1.8% w/w glycerin, 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide IN to adjust the pH at 7.3 - 7.5 and water q.s. to 100% w/w; e) adding an aliquot of the aqueous vehicle 2 to the slurry of step c) to obtain a concentration of fluticasone propionate of about 1% w/w; f) applying high-shear, high-speed mixing to the slurry of step e) till to obtain the targeted mean particle size; g) sterilizing the nanosuspension of step f) by autoclaving; h) preparing an aqueous vehicle 3 containing: 0.9% w/w glycerin, 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide to adjust the pH at 7.3 - 7.5 and water to 100% w/w; and sterilizing the aqueous vehicle 3 by filtration; i) aseptically adding an aliquot of the sterile aqueous vehicle 3 to the sterilized nanosuspension of step g) to prepare a sterile topical ophthalmic aqueous nanosuspensions containing the targeted concentration of fluticasone propionate nanocrystals Form A; wherein the nanocrystals of fluticasone propionate Form A have a X-ray powder diffraction pattern of said nanocrystals including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5 degrees 2Θ, further including peaks at about 9.9, 13.0, 14.6, 16.0, 16.9, 18.1, and 34.3 degrees 2Θ, and wherein the nanocrystals are nanoplates having the crystallographic axis substantially normal to the surfaces that define the thickness of the nanoplates. a) preparing an aqueous vehicle 1 containing: 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide IN to adjust the pH at 7.3 - 7.5 and water to 100% w/w; b) mixing an amount of fluticasone propionate Form A nanocrystals having a mean particle size from 100 nm to 1000 nm with an amount of aqueous vehicle 1 to obtain a slurry containing a concentration of fluticasone propionate of 2% w/w; c) applying high-shear, high-speed mixing to the slurry of step b) for at least 10 minutes; d) preparing an aqueous vehicle 2 containing: 1.8% w/w glycerin, 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide IN to adjust the pH at 7.3 - 7.5 and water q.s. to 100% w/w; e) adding an aliquot of the aqueous vehicle 2 to the slurry of step c) to obtain a concentration of fluticasone propionate of about 1% w/w; f) applying high-shear, high-speed mixing to the slurry of step e) till to obtain the targeted mean particle size; g) sterilizing the nanosuspension of step f) by autoclaving; h) preparing an aqueous vehicle 3 containing: 0.9% w/w glycerin, 0.5 % w/w methylcellulose 4000 mPa·s, 1.0% w/w boric acid, 0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric acid IN and / or sodium hydroxide to adjust the pH at 7.3 - 7.5 and water to 100% w/w; and sterilizing the aqueous vehicle 3 by filtration; i) aseptically adding an aliquot of the sterile aqueous vehicle 3 to the sterilized nanosuspension of step g) to prepare a sterile topical ophthalmic aqueous nanosuspensions containing the targeted concentration of fluticasone propionate nanocrystals Form A;