Water is widely used as raw material, ingredient and solvent in the processing, formulation and manufacture of pharmaceutical products, active pharmaceutical ingredients (APIs) and intermediates.
It may present as an excipient, used for the reconstitution of products, during synthesis or during the production of finished products. Water in the pharmaceutical industry has uses beyond production including rinsing and cleaning of vessels, equipment and primary packing materials.
Water used for pharmaceutical applications is characterised by different grades, several of which are described in USP monographs and specify uses, acceptable methods of preparation, and quality attributes. Different grades of water quality are required depending on the different pharmaceutical uses. Water for pharmaceutical use is divided into two varieties: bulk water and packaged water. Bulk waters are produced on-site where they are used while packaged waters are produced, packaged, and sterilised to preserve microbial quality throughout their packaged shelf life.
Controlling the quality of water, in particular, microbiological quality, is a major concern and the pharmaceutical industry devotes considerable resources to ensuring their water treatment systems are of the highest quality and suitably maintained.
We introduce you to water for pharmaceutical use, starting with understanding the different types of impurities present in the source water.
Dissolved Impurities
These include dissolved gases, inorganic salts or metallic impurities and organic impurities.
a. Dissolved gases: Gases such as Chlorine, Ammonia, Carbon-di-oxide, Hydrogen Sulfide, are sparingly soluble in water.
b. Inorganic salts or Metallic impurities: Metallic salts readily dissolve in water. They dissociate into charged ions i.e. cations (a++, Mg++, Na+ , K+ , Fe++, Al+++) and anions (CO3–, Cl–, SO4–, NO3)
c. Organic Impurities: These include different types of hydrocarbons, alcohols, aldehydes and ketone.
Suspended Impurities
These are slightly larger particles that do not dissolve in water and remain in the suspended state. They include insoluble solids dust, fine sand, clay, animal particles, oil globules, among others. The technical term used to measure the total amount of suspended impurities is called TSS or Total Suspended Solids.
Colloidal Impurities
These are the smaller impurities that are present in the water in all three states: solid, liquid or gaseous. These include Silica, Al(OH)3, Fe(OH)3, organic waste products, colouring matter, amino acids, etc.
Microbial Impurities
Biological contamination of water is caused by the presence of living organisms like algae, bacteria, protozoa, pathogens, microbes, viruses, parasites and their eggs (cysts). Collectively known as microorganisms, it is critical to ensure their complete removal from water for pharmaceutical uses.
In the next post, we explain the different types of waters used for pharmaceutical manufacturing.
