Generator sterilization

Filtration of the final product through a 0.22 pm absolute filter in order to generate sterile product, followed by its aseptic filling into final product containers. 

Finished parenteral products prepared in the radiopharmacy department must be sterile. Based on a risk analysis one may conclude that the risk of non-sterility is very low for standard radiopharmaceutical kit preparations. The risk of contamination is somewhat higher for the eluate from radionuclide generators, especially when they are used for a long period. The injection bottle on top of a Tc generator (sterile sodium chloride solution for injection) is changed asepti-cally each day however, the inside of the generator system is not sterilised nor disinfected. For that reason it is recommended to control the microbiological quality of the... 

Equipment Steam generator, sterilizer, LPG tank, vessel, piping, heat exchangers, chemical oven, cylinders, tanks... 

Generation Wild female population Wdd females mated to sterile males, % Theoretical population of fertile females... 

Chlorine Dioxide. Like ozone, chlorine dioxide [10049-04-4] is a powerflil oxidant. It is usually generated as used. It has been used for disinfecting drinking water and bleaching paper pulp. Its effectiveness in killing microorganisms is well documented (305,306), and it has received recent study as a gas to sterilize medical devices. It requites 50% rh or higher to be effective. Bacterial cells had a D-value of 2.6 min and spores of 24 min (307). 

ElectrolyticaHy generated hypochlorite may be used for the oxidative destmction of cyanides (qv) or the sterilization of domestic wastes. Several on-site systems for swimming pool sterilization and municipal waste treatment works have been developed. One of these systems is described in Reference 124. On-site production and immediate use of chlorine is considered safer than the transportation of chlorine. 

Where small quantities of high-purity steam is required for electronic chip, pharmaceutical, sterilization, food preparation, and similar process applications, a small risk of steam contamination may exist. This may be caused directly by the use of amine treatments or indirectly through process contaminants or the transport of iron oxides. Consequently, alternative arrangements for steam generation are made. 

Carbon filters find particular application as prefilters for RO and ion-exchange processes in the production of high purity FW. They are also used in clean-steam boilers and other types of steam generators where the steam is ultimately destined for application in food or beverage production, pharmaceuticals, electronics, surgical instrument sterilization, and similar processes. 

Radioisotopes have important commercial applications. For example, americium-241 is used in smoke detectors. Its role is to ionize any smoke particles, which then allow a current to flow and set off the alarm. Exposure to radiation is also used to sterilize food and inhibit the sprouting of potatoes. Radioisotopes that give off a lot of energy as heat are also used to provide power in remote locations, where refueling of generators is not possible. Unmanned spacecraft, such as Voyager 2, are powered by radiation from plutonium. 

The production of benzylpenicillin is very sensitive to temperature. A lot of metabolic heat is generated and the fermentation temperature has to be reduced by controlled cooling. This heat transfer is achieved by circulating chilled water through banks of pipes inside the vessel (which also serve as baffles) or through external limpet coils on the jacket of the vessel. These coils consist of continuous lengths of pipe welded in a shallow spiral round the vessel. This cooling water system is also used to cool batched medium sterilized in the vessel prior to its inoculation. 

Steam for sterilization can either be generated within the sterilizer, as with portable bench or instrument and utensil sterilizers, in which case it is constantly in contact with water and is known as wef steam, or can be supplied underpressure (350-400kPa) from a separate boiler as dry saturated steam with no entrained water droplets. The killing potential of wef steam is the same as that of dry saturated steam at the same temperature, but it is more likely to soak a porous load creating physical difficulties for further steam penetration. Thus, major industrial and hospital sterilizers are usually supplied with dry saturated steam and attention is paid to the removal of entrained water droplets within the supply line to prevent introduction of a water fog into the sterilizer. 

The greatest risk of contamination of a pharmaceutical product comes from its immediate environment. Additional protection from particulate and microbial contamination is therefore essential in both the filling area of the clean room and in the aseptic unit. This can be provided by a protective work station supplied with a unidirectional flow of filtered sterile air. Such a facility is known as a laminar airflow unit in which the displacement of air is either horizontal (i.e. from back to front) or vertical (i.e. from top to bottom) with a minimum homogenous airflow rate of 0.45 ms" at the working position. Thus, airborne contamination is not added to the work space and any generated by manipulations within that area is swept away by the laminar air currents. 

Efficiency testing of high-efficiency partieulate air (HEPA) filters used for the supply of sterile air to aseptie workplaces (Chapter 22) is normally achieved by the generation upstream of dioetylphthalate (DOP) or sodium ehloride particles of known dimension, followed by deteetion in downstream filtered air. Retention efficiency is reeorded as the percentage of partieles removed under defined test conditions. Microbiological tests are not normally performed. 

Fig. 23.2 Isolators used for sterility testing. The operator works within the hood which is suspended inside the cubicle the hydrogen peroxide generator which is used to sterilize the isolators is shown in the left foreground. (Courtesy of SmithKline Beecham Pharmaceuticals.)...

Ozone can also be used as an oxidizing agent, but because of its instability, it must be generated on-site. It is a powerful oxidant for some organic materials, but others are oxidized only slowly or not at all. Ozone is only suitable for low concentrations of oxidizable materials. A common use is for the sterilization of water. 

---