Abstract: The present invention provides an improved novel process of manufacturing a sterile, ophthalmic pharmaceutical suspension comprising an active ingredient(s) such as carbonic anhydrase inhibitors (CAIs) wherein the said process involves solubilization, followed by controlled precipitation of carbonic anhydrase inhibitors of the right particle size, e.g., less than 10 micron, preferably less than 5 micron (D90) by varying pH with a little or no homogenization. Said process further does not require the use of any special equipment such as ball mill, milling bottle and/or jet mill. This newly improved process is simple, cost effective and efficient.

Abstract: An aqueous suspension of a carbonic anhydrase inhibitor such as brinzolamide as well as methods of preparation thereof, are disclosed. The suspension comprises an organic polar solvent such as dimethyl sulfoxide and/or a non-aromatic non-ionic polyethoxylated surfactant such as polyethoxylated castor oil and/or or polysorbate 80. Methods include precipitating brinzolamide from the heated composition. Methods also include sonication of the suspension to reduce brinzolamide particle size.