[Original] Understanding of Water Making-Gao Yueqing (Production Department)



According to CMP regulations, pharmaceutical water should be suitable for its purpose and meet the quality standards and relevant requirements of the Pharmacopoeia of the People's Republic of China. Pharmaceutical water should be at least drinking water. Therefore, pharmaceutical water is divided into drinking water, purified water, water for injection and pure steam produced with purified water. Drinking water is mainly used as the source of water for the preparation of purified water, and the initial washing of equipment and containers. Purified water is mainly used as water for injection and the water source for the production of pure steam, the last washing water for equipment, utensils and packaging materials that directly contact with non-sterile drugs, the initial washing of injections and sterile bottles, and the ingredients of sterile drugs. Water for injection should be used for the final cleaning of packaging materials where sterile products are in direct contact with drugs, and for the refining of sterile raw materials. Pure steam is mainly used for moist heat sterilization of containers, equipment and rubber plugs. The production process of

purified water, injection water and pure steam is as follows: raw water (reaching drinking water standard) → flocculant → mechanical filter → activated carbon filter → scale inhibitor → precision filter → primary reverse osmosis device → intermediate water storage tank → alkali tank → secondary reverse osmosis device → purified water storage tank → ultraviolet lamp disinfection → precision filter → each use point in the workshop. Water for injection is mainly prepared by using purified water with multi-effect distilled water machine, and then distributed to the use points of each workshop. When distributing water to each workshop, there should also be return water pipeline to ensure the circulation of purified water and injection water, and avoid the generation of dead water point and stagnant water. Water for injection should also be kept in circulation above 70 ℃. Among them, the activated carbon filter is mainly used to remove harmful substances such as free chlorine, chroma, microorganisms, organic matter and some heavy metals in the water to prevent them from affecting the reverse osmosis membrane system. Scale inhibitor is to prevent the reverse osmosis concentrated water calcium carbonate, magnesium carbonate, calcium sulfate and other insoluble salt concentration after precipitation scaling block reverse osmosis membrane, thereby damaging the application characteristics of membrane elements. The NaOH dosing device is used to adjust the pH value of the influent, so that the CO2 gas in the secondary reverse osmosis influent is dissolved in the water in the form of ions to control the conductivity.

In order to control risks and ensure that the pharmaceutical water produced conforms to national regulations, the 10th edition of China's Pharmacopoeia stipulates the inspection items for purified water and water for injection. Among them, non-volatile matter, heavy metal, nitrate, nitrite, microbial limit, total organic carbon (TOC), pH, electrical conductivity and ammonia are both items that need to be checked. Total organic carbon and easy oxide in purified water can be selected. Water for injection additionally requires checking bacterial endotoxin.

TOC, pH, conductivity are tested on site, and other project laboratories are tested. The pH and conductivity are measured every 2 hours. The inspection of these items is generally based on online detection, supplemented by offline detection. On-line testing is generally the measuring device and instrument carried by the production equipment itself, and off-line testing is mainly QC's regular sampling and testing of pharmaceutical water.