Pharmaceutical Waters Used in Sterile and Nonsterile Compounding

Water is the most abundant substance on earth, covering about 70% of the earth's surface. Life is dependent upon water and the water cycles involved. In pharmaceutical compounding, water is the most widely used excipient employed as a solubilizing agent and as a vehicle; it is also used medicinally. With the variety in dosage forms, there are different types of waters that are used, some with specific uses and some more general. For the different types or categories of water, there are different methods of preparation, different characteristics, and different properties that can be used as an advantage in compounding. This article describes the different categories of waters, their use, preparation, characteristics, and water chemistry in general.