Several methods of water preparation for injection.

Distillation method is a reliable and classical method for preparing water for injection.
pharmacopeia requires that the water source for distillation legal injection should be purified water, so raw water needs to be filtered, ion removal and other processes purified before it can be used.
preparation process for injecting water: (1) raw water treatment.
water is usually pre-treated tap water and its quality should be in accordance with national sanitary standards for drinking water.
the raw water contains aerosols, soluble inorganic salts, organic matter, microorganisms, thermogens and volatile gases and other impurities, must be treated as purified water before it can be used as a water source for distillation and injection.
water treatment methods are ion exchange, electrodialysis and reverse osmosis.
(1) ion exchange method Ion exchange method treatment of raw water is carried out through ion exchange resin.
commonly used ion exchange resins are 732 styrene strong acidic cation exchange resin and 717 styrene strong alkaline anion exchange resin.
Generally using cation resin bed, anion resin bed, mixed and resin bed series combination, after the cation resin bed plus a degassing tower, remove carbon dioxide from the water, to reduce the burden of anion resin.
The result of this method is high water chemistry purity, than resistance of up to 1 million omega.cm or more, simple equipment, fuel savings and cooling water, low cost;
(2) electrodialysis method Electrodialysis method is based on the directional migration of ions under the action of electric field and exchange membrane selection through the removal of ions.
This method does not need to consume the acids and alkalis used in ion exchange resin regeneration, which is economical compared to ion exchange method, but the water purity is lower than the resistance is generally 50,000 to 100,000 . . . cm; The semi-permeable membrane is placed on both sides of the salt solution and pure water, and the water molecules on the pure water side are transferred from the semi-permeable membrane to the salt solution side, raising the surface of the salt solution, which is the permeation process (osmosis).
pressure formed by the height difference between the two sides of the liquid column is the osmosis pressure of this salt solution.
If a pressure greater than the permeable pressure of the salt solution is applied to the salt solution, the water molecules in the salt solution penetrate to the pure water side, reaching the separation of salt and water, which is reverse osmosis.
the transverse osmosis method purifying raw water is generally selected semi-permeable membrane for acetic acid fiber membrane and polyamide film.
(2) distillation.
production of small quantities of general tower distillation water, including evaporation pot, foam isolation device and condenser three parts.
of large-scale production, multi-effect distilled water or air pressure distiller is commonly used.
water for the preparation of injection water, an effective insulation device should be installed to ensure that it is not carried into the thermogen.
(3) water for injection is collected and stored.
Discard the initial distillate, check qualified and collect it using a closed collection system with a sterile filtration device, store it in a heat-insulation cycle above 80 degrees C, an insulation cycle above 65 degrees C, or a sterile state below 4 degrees C, and use them in preparation for 12h.
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