Water Part3

Editor's Notes

• #2: दिसंबर 4, 2012
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• #4: दिसंबर 4, 2012 8 . Inspection of water systems WPU (PW, HPW and WFI) systems are likely to be the subject of regulatory inspection from time to time. Users should consider conducting routine audit and self-inspection of established water systems . This GMP guidance can be used as the basis of inspection. The following list identi.es items and a logical sequence for a WPU system inspection or audit : — a sampling and monitoring plan with a drawing of all sample points ; — the setting of monitoring alert and action levels ; — monitoring results and evaluation of trends ; — inspection of the last annual system review ; — review of any changes made to the system since the last audit and check that the change control has been implemented ; — review of deviations recorded and their investigation ; — general inspection of system for status and condition ; — review of maintenance, failure and repair logs; and — checking calibration and standardization of critical instruments . For an established system that is demonstrably under control, this scope of review should prove adequate. For new systems, or systems that display instability or unreliability, the following should also be reviewed : — performance quali.cation ; — operational quali.cation; and — installation quali.cation .
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• #11: दिसंबर 4, 2012 Well water: Some pharmaceutical manufacturers need to draw water from wells or bore holes. Some manufacturers feel they have better control of water from their own wells than from a municipal source. The aquifer that the well taps into may be contaminated, or the construction materials of the well could contribute to contamination. The exposed parts of the well should be inspected periodically for cracked, corroded, or damaged casing , broken or missing well caps , and settling and cracking of surface seals . The depth of the well should also be determined – the shallower the well the greater is the chance of contamination from surface contaminants. Check: The use of nearby septic systems (which could contribute coliforms or faecal bacteria). If there are hazardous materials used nearby. Sometimes these are disposed of in nearby septic system s .   Hazardous materials include: Pesticides – farmers in areas near the well could use pesticides, which can permeate through the aquifer. Fertilizers , such as nitrates and phosphates, can be troublesome to remove and can encourage the proliferation of micro-organisms, especially algae if there is any light available. Herbicides – organophosphates can enter the aquifer. F uels , such as diesel and petrol spills can also be problematic. Testing records to show water is “potable”. Records of well maintenance. The manufacturer must have procedures such as disinfection procedures or sediment removal , together with the use of any chemicals in the well . Chemicals that can leach include the oils used to lubricate the pumps.
• #12: दिसंबर 4, 2012 Large scale storage: Raw water storage may be required according to local circumstances, such as intermittent water supplies. Storage can be typically in cisterns or reservoirs made of concrete or tanks made of steel. Sometimes plastic or rubber bladders are used but these can cause significant problems with leachates and odours. Check the material of construction: - Concrete and steel are acceptable, but check corrosion; - Plastics or plastic linings may leach plastizisers such as phthalates. The storage must have adequate cover to keep out insects, birds and animals. However, an air filter is not usually necessary. The quality of the raw water in this type of storage needs to be periodically checked and a physical inspection carried out. Disinfection of the water is required. This is usually with chlorine at concentrations of 1 – 2 ppm. The chlorine levels need to be checked periodically. The storage tanks should be covered because the chlorine may have a life of only a few hours, and algal blooms may be encouraged if water is exposed to sunlight. UV lights suspended in these tanks are not effective bactericides. Periodically the tank should be emptied and cleaned.
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• #16: दिसंबर 4, 2012 Inspection: (Contd.) Check pipes and pumps. The photograph shows a good example of a neatly laid-out water treatment room with good equipment and pipes. There are hygienic couplings (Ladish® or Tri-Clover ® clamps), welded pipes and hygienic pumps. Note also hygienic sampling points.
• #17: दिसंबर 4, 2012 Inspection: (Contd.) Assess physical condition of equipment. Look for stains and leaks that could indicate problems. Check to make sure heat exchangers are double tube or double shell. If not, there should be continuous pressure monitoring to ensure the heating or cooling liquid does not contaminate the pure water through any pinholes. For single plate heat exchangers, the pressure of the heating or cooling liquid must be LOWER than the purified water at all times. An exception may be where the liquid is of a higher purity than the water being produced. Note from the heat exchanger example above that even high grade stainless steel, such as 318SS, can be subject to pit corrosion!
• #18: दिसंबर 4, 2012 Inspection: (Contd.) Check maintenance of the entire system by examining the maintenance procedure and records. For example, check the “O” rings of connections and the maintenance of the pump seals. The pump on the left shows good connections and a good standard of engineering. The one on the right shows a threaded coupling, called a milk coupling or sanitary coupling . Threaded couplings and couplings in general should be avoided whenever possible. Where welding is impossible, hygienic couplings should be used or milk (sanitary) coupling, which are acceptable since the threaded fitting is not part of the fluid pathway, and so should not contaminate the water. The inspector must be satisfied that hidden seals and “O” rings have actually been removed, examined and/or replaced during maintenance.
• #19: दिसंबर 4, 2012 Inspection: (Contd.) Check air filters which should be hydrophobic (otherwise, they can be blocked by a film of water condensate) and should be able to be sanitized. Those on WFI plants should be be able to be sterilized and integrity-tested. Check replacement frequency, which the pharmaceutical manufacturer should determine with assistance from the filter supplier. Check burst discs because if they have ruptured without being noted the storage system can become contaminated.
• #20: दिसंबर 4, 2012 Inspection: (Contd.) By-pass valves and by-pass lines are often used for maintenance procedures. In critical situations there may be, for example, two pumps in parallel, in case one breaks down. Additionally, engineers like to be able to replace a pump or a filter without dismantling large sections of the system. However, valves in by-pass lines can leak, be left open, or be contaminated, and so they are undesirable. A “blanking” piece is often better during operation of the system, so that there is no physical connection.
• #21: दिसंबर 4, 2012 Inspection: ( Contd.) Further points to check: Activated carbon bed sanitization – these can become overgrown with bacteria quite quickly. Check sanitization frequency to ensure the AC remains uncontaminated. Calibration of temperature-compensated conductivity meters is often overlooked or not done properly. Influence of plastic pipe adhesive on Total Organic Carbon (TOC) compliance - some adhesives will leach into the water and these can be volatile. Non-condensable gases in pure steam – for example nitrogen and oxygen. They affect the apparent pressure of sterilization processes, lowering their effectiveness.
• #22: दिसंबर 4, 2012 Inspection: (Contd.) Further points to check: Polypropylene welding inspection. If polypropylene pipe is used and welded, has the manufacturer checked for pin holes? Retrospective validation of WFI system. Many water plants are 10 – 20 years old and may not have been properly validated. Can they be properly retrospectively validated? Rouging of WFI Systems. The high temperatures of these storage and distribution systems seem to lead to a build up of a deposit known as rouge . Check to see if the manufacturer carries out a periodic physical check for this effect, and what steps are taken to remove the rouge. Sometimes re-passivation is effective. Spray ball efficacy. This is not easy to determine and must be assessable. If the spray ball is jammed it will not work properly, but because it cannot be seen it is not easy to check. There are non-rotating or fixed spray balls or spray cones which may be better in small systems.
• #23: दिसंबर 4, 2012 Inspection: (Contd.) Further points to check: UV light – monitoring performance and lamp life. The lethal radiant energy from UV lights drops off quickly, so many have to be replaced approximately every 6 months. Does the manufacturer have an hour meter and is the lamp replaced according to the supplier’s recommendations? Can the intensity of the light be measured? Validating ozone dosage is difficult. It may be possible for the manufacturer to get the supplier’s validation studies showing worst case lethal effects. Water softener sodium chloride specifications. Like any ancillary material, the salt, acids and alkalis used as consumables in water treatment plant should have purchase specifications. Note: testing is not required unless for trouble shooting purposes. Check the drawings to see if valves are marked as “Normally Open” or “Normally Closed”, then physically check the valve position. It is surprising sometimes that valves are not returned to the correct operating position; for example, after de-ionizer regeneration.
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• #25: दिसंबर 4, 2012 Sampling: There must be a sampling procedure. The sample integrity must be assured. The sample received in the laboratory must reflect the bulk water’s physical, chemical, and biological quality. Because of water’s solvent properties and the nature of micro-organisms, this can change very quickly. For example, the microbe population in ideal circumstances can double or triple every hour. Microbes can grow at very low temperatures and in extremely low nutrient levels. Even distilled water may have enough nutrients to support organisms such as some of the pseudomonas species. The persons who take the sample should also have training on aseptic handling practices, to ensure that they do not contaminate the sample while it is being taken. The sample point should be hygienic and the practice of flushing it, or not, should follow manufacturing practice. Sample points for subsystems, such as de-ionizers and RO’s, should be as close to the downstream side as possible in order to reflect the quality of the water being fed to the next subsystem. All water outlets in the factory should also be checked periodically. This should be done unannounced, if possible, so that water can be sampled through any attachments to the outlet, such as hoses or pumps. Sample sizes of at least 100 – 500mL are required; samples of 1 or 2 mL are unacceptable.
• #26: दिसंबर 4, 2012 Sampling: (Contd.) The sample container should be sterile, inert, and able to be securely closed. Plastic containers that are re-sterilized sometimes distort in the autoclave, so that the quality of recycled containers should be carefully checked. Some plastics may leach and thus affect tests such as the TOC test. Single-use, sterile, inert plastic bags are available. However, these could prove too expensive for some manufacturers to consider. The container must be properly labeled. The label should have the date, time and location sampled as well as the sampler’s name or initials. It must be attached firmly to the container. Felt tip permanent markers are satisfactory but may leach solvent if used on plastics, and may thus affect the TOC test. It is important for the label to be properly removed should the container be recycled. Unless tested within a few hours, the sample should be chilled to less than 8 o C, but not frozen. Samples from heated water systems should be rapidly cooled. If a sample is to be transported to a remote laboratory, refrigerated packing must be allowed for to ensure that the sample stays cool. Inclusion of a temperature data logger is good practice. On arrival at the laboratory the condition and temperature of the sample should be noted, as this may be important if an out of specification result needs to be investigated. It is good practice to have a sample registration and tracking system. The laboratory should record the time at which microbial testing started.
• #27: दिसंबर 4, 2012 Testing: Method Verification - The methods must be validated or verified in the laboratory, even if they are pharmacopoeial methods. Chemical testing - Chemical testing follows normal laboratory practices. However, TOC requires sophisticated, expensive equipment and trained technicians, which may put it beyond the reach of some manufacturers. Microbiological testing - It is important that microbiological testing be conducted in a well-equipped laboratory with adequate resources. Method : The common methods for microbial total count are Most Probable Number Test (not reliable for low numbers), Spread or Pour Plate (can only test only 1 or 10mL respectively; not reliable for low counts) or membrane filtration, which is preferred. Media : There are various types of test media that can be used. Incubation time and temperature : Preferably 32 o C or lower (higher temperatures than this inhibit aquatic microflora) and up to 5 days (sub-lethally damaged organisms may not revive quickly). Objectionable and indicator organisms: Any organism which can grow in the final product, or can cause physical and chemical changes to the product, or is pathogenic, is unacceptable in purified water. Indicator organisms, such as Escherichia coli or coliforms, point to faecal contamination. They “indicate” possible contamination by other pathogenic organisms. The manufacturer must set specifications for total count and absence of objectionable and indicator organisms. The USP recommends a limit of 100 total aerobic microbial colony-forming units (CFU) per mL for purified water.
• #28: दिसंबर 4, 2012 Sampling locations and limits for microbiological testing: The limits are not from any official literature and are thus intended merely as a guide. The table is a suggested list of sampling locations and limits (for total aerobic microbial plate count). Note that in some countries, the “Action” required if out of specification results are detected may well include recall of therapeutic goods even if they meet finished goods specification. This is because the water treatment system is seen to be out of control. Prudent manufacturers should react promptly to “alert” limits so that the system remains in control. CFU = colony forming units
• #29: दिसंबर 4, 2012 Pyrogens and endotoxins: Any compound giving rise to fever when injected into mammals is a “Pyrogen”. Even sterile water can be pyrogenic. Endotoxins are pyrogenic, and they come from Gram negative bacterial cell wall fragments. Esc h erichia coli appears to be the main culprit. Endotoxins are highly toxic to mammalian cells and are one of the most potent modulators of the immune system. If injected into mammals they cause fever. Endotoxins can be detected using a test for lipopolysaccharides . The Rabbit test detects pyrogens, and the LAL test detects endotoxins. Ultra-filtration, distillation, and RO may remove pyrogens.
• #30: दिसंबर 4, 2012 In this group session, you are given a schematic of a water system ( See handout 2-3-24) . Discuss the drawing and list any problems and their solutions. (Note to trainer: The following handout 2-3-25, giving correct answers, should not be distributed until after discussion.)
• #31: दिसंबर 4, 2012 This slide indicates the modified water schematic. (See handout 2-3-25.)