Water for pharmaceutical use is one of the most commonly used raw materials in the pharmaceutical industry. It is used for the formulation of products where it serves as an excipient or solvent, in the synthesis of active pharmaceutical ingredients and excipients, for reconstitution of certain medications, for cleaning and rinsing laboratory glassware, packaging, manufacturing equipment, and spaces, in the sterilization process using saturated steam under pressure (autoclaving), in the analysis of pharmaceutical substances and products, and so on.
If water of inferior quality is used, it can lead to changes in the composition of the product and its characteristics, which may result in undesired side effects or reduced product effectiveness.
Pharmaceutical water encompasses two main types of water: purified water (PW) and water for injections (WFI).
lat. Aqua purificata;
Purified water (PW) is water intended for the production of medical/pharmaceutical products where sterility and pyrogenicity are not required.
Purified water in bulk at the Institute of Virology, Vaccines, and Sera “Torlak” is produced through the process of double reverse osmosis from water that meets the requirements of relevant regulatory bodies for water for human use (water from the city water supply).
During the process of reverse osmosis, water purification is carried out through special membranes, with water flowing in the opposite direction of the osmosis process. The reverse osmosis membrane (RO membrane) is semi-permeable and has pore sizes smaller than those of parasites and most bacteria, enabling the elimination of a wide range of contaminants from the water. The RO membrane is located in a membrane housing exposed to high pressure.
The quality of PW water meets the requirements of the Pharmacopeial specifications (PhEur) regarding chemical and microbiological purity.
The characteristics of PW water produced at the Institute of Virology, Vaccines, and Sera “Torlak” are provided in the table.
| Nitrates | ≤0,2ppm |
| Heavy metals | ≤0,1ppm |
| Total organic carbon (TOC) | ≤0,5ppm |
| Conductivity | ≤4,3 µS/cm na 20°C |
| Total count of viable aerobic microorganisms | ≤100 cfu/1mL |
Besides pharmaceutical applications, PW water is also used in the food industry. As high-quality water, it is recommended for use in water baths, medical and laboratory devices, steam irons, car radiators, antifreeze, batteries, for photochemistry, and many other purposes.
Water for injections, WFI
To obtain water for injections of the required quality, we have precisely defined the framework of the water production technology for injections, as well as the requirements for the final phase of processing, storage, and distribution, qualifications, implementation, and monitoring of system sanitation. Validation and qualification of systems for water purification, storage, and distribution are an integral part of Good Manufacturing Practices (GMP). Water for injections is obtained through further processing of purified (PW) water. The production of Water for Injections in bulk at the Institute of Virology, Vaccines, and Sera “Torlak” involves procedures such as ion exchange, reverse osmosis, electrodeionization, and distillation.
Water for injections is used for the most critical pharmaceutical products and applications, including mandatory use for injectable drugs, hemofiltration, production of some active pharmaceutical ingredients, implantable medical devices, among others.
The quality of Water for Injections meets the requirements of the European Pharmacopoeia (PhEur) regarding chemical and microbiological purity.
Characteristics of Water for Injections in bulk produced at the Institute of Virology, Vaccines, and Sera “Torlak” are provided in the table.
| Nitrates | ≤0,2ppm |
| Heavy metals | ≤0,1ppm |
| Total organic carbon (TOC) | ≤0,5ppm |
| Conductivity | ≤1,1 µS/cm na 20°C |
| Total count of viable aerobic microorganisms | ≤10 cfu/100mL |
| Bacterial endotoxins | ≤0,25 EU/mL |
Water for Injections (WFI) in bulk is not sterile. Without final sterilization, it cannot be used in the production of parenteral preparations. For the production of all other pharmaceutical forms, WFI in bulk can be used, considering that according to the Pharmacopoeia, WFI in bulk is of the highest quality.
The Institute of Virology, Vaccines, and Sera “Torlak” also produces sterile water for injections. Sterile water for injections is water packaged in appropriate containers and then sterilized. It is packed in single-dose containers of no more than 1L capacity. Sterile WFI water is produced, packaged, and sterilized to preserve microbiological quality throughout its shelf life.
