Commonly used sterilization methods are hot and humid sterilization method, dry heat sterilization method, radiation sterilization method, gas sterilization method and filter sterilization method. Sterilization can be combined using one or more methods according to the characteristics of the sterilized article. As long as the items permit, should be used as far as possible the final sterilization method sterilization. If the items are not suitable for the final sterilization method, the filter sterilization method or sterile production process can be used to meet the requirements of sterility assurance, as long as possible, non-final sterilization of the items for supplementary sterilization (such as circulating steam sterilization).
1, hot and humid sterilization method
This law refers to the method of placing the article in the sterilization cabinet by using high-pressure saturated steam, superheated water spray and other means to microbial cells in the protein, nucleic acid degeneration and kill the microorganisms. The method of sterilization ability. For the most effective heat sterilization, the most widely used sterilization method. Drugs, containers, media, aseptic clothing, rubber plugs and other items that are not subject to change or damage due to high temperature and humidity. Can be sterilized using this method. Circulation of steam can not completely kill the bacteria spores, generally can be used as heat-resistant sterile products, auxiliary sterilization means.
The choice of hot and humid sterilization conditions should take into account the thermal stability of the sterilized items, heat penetration, microbial contamination and other factors. Damp heat sterilization conditions are usually carried out at 121 ° C x 15 min, 121 ° C x 30 min or 116 ° C for 40 min. Other temperature and time parameters may be used, but no matter what sterilization temperature and time parameters are used, Sterilization process and monitoring measures in the normal operation of the process to ensure that items after sterilization SAL ≤ 10- When the sterilization procedure is selected using the F0 value concept (F0 is the standard sterilization time, the sterilization process gives sterilization time at 121 ° C for the sterilized product), special measures should be taken to ensure that the sterilized article is available Sufficient sterility assurance, at this time, in addition to verification of the sterilization process, but also in the production process to monitor the micro-organisms to prove that the pollution of microbial indicators below the set limit. For heat-stable items, the sterilization process may be preferred to over-kill the law to ensure that the sterilized items are obtained asymptomically guaranteed. Thermal instability products, the determination of its sterilization process depends on a certain period of time, a certain production batch of sterilized items before sterilization of the level of microbial contamination and heat resistance. Therefore, the daily production of the whole process of pollution of microorganisms in the product should be continuously and strictly monitored. And take various measures to reduce the level of microbial contamination of goods, in particular to prevent the pollution of heat-resistant bacteria. The F0 value of the thermally unstable item is generally not low for 8 min.
When using hot and humid sterilizers for hot and humid sterilization, the sterilized items should be properly loaded and can not be arranged in order to ensure the effectiveness and uniformity of sterilization.
The hot and humidifying method should confirm that the sterilization cabinet may have a cold spot at different loading conditions. When the biological indicator is used to further confirm the sterilization effect, it should be placed in the cold spot. Commonly used biological indicators of water for Bacillus stearothermophilus spores (Spores of Bacillus stearothermophilus).
The sterilizer produced by Huanyu is characterized by thorough sterilization and rapid sterilization.
2, dry heat sterilization method
This law refers to the items placed in dry heat sterilization counters, tunnels and other sterilizer equipment, the use of dry and hot air to kill microorganisms or eliminate pyrogenic substances. It is suitable for sterilization such as glassware, metal container, fiber product, solid reagent, liquid paraffin and so on, which can be sterilized by heat and sterilization.
Dry pyrophoric conditions are generally 160 ~ 170 ℃ × 120min above, 170 ~ l80 ℃ × 60min or more or 250 ℃ × 45min or more, other temperature and time parameters can also be used. No matter what kind of sterilization conditions, should ensure that the sterilized items SAL ≤ 10-6. The use of dry hot over-killed items generally do not need to be sterilized before the determination of contaminating microorganisms. 250 ℃ × 45min dry heat sterilization can also remove the sterile product packaging containers and the production of filling equipment in the hot material.
In dry state sterilization, the sterilized items should be properly loaded, can not be arranged too close to ensure the effectiveness and uniformity of sterilization.
Dry heat sterilization method should ensure that the temperature distribution in the sterilization cabinet meets the set criteria and determines the coldest point position. Commonly used biological indicator for the Bacillus subtilis spores (Spores of Bacillus subtilis). Bacterial endotoxin inactivation validation test is a test to demonstrate the effectiveness of the pyrogenic process. Generally, less than 1000 units of bacterial endotoxin are added to the subject to be pyrogen, proving that the pyrogenic process can reduce the endotoxin by at least 3 log units. Bacterial endotoxin inactivation test The bacterial endotoxin used in the test is generally Escherichia coli endoxin.
3, radiation sterilization method
This law means the method of killing the microorganism by placing the article in an electron beam suitable for the radiation of the radiation source or the electron beam in the appropriate electron accelerator. This method is most commonly used for 60Co-γ-ray radiation sterilization. Medical equipment, containers, production of auxiliary supplies, raw materials and products not subject to radiation damage can be sterilized by this method.
The use of radiation sterilization sterilization of the sample SAL should be ≤ 10-6. The parameters controlled by gamma-ray radiation sterilization are mainly radiation doses (refer to the absorbed dose of sterilized items). The dose of the dose should be considered for the suitability of the sterilized article and the maximum amount of microorganisms that may be contaminated and the strongest radiation resistance. The dose to be used in advance should not affect the safety, efficacy and stability of the sterilized article. Commonly used radiation sterilization absorbed dose of 25kGy. For end products, APIs, certain medical devices should be sterilized with minimal radiation dose as far as possible. Prior to sterilization, the amount of microbiological contamination and the antiradiation intensity of the sterilized article should be determined to evaluate the sterilization level of the sterilized item. For the established dose, should be regularly reviewed to verify its effectiveness.
Sterilization should be carried out using appropriate chemical or physical methods to monitor the amount of radiation absorbed by the sterilized article. To fully confirm that the dose absorbed by the sterilized article is within the prescribed limits. In the case of a radioactive dosimeter, which is irradiated with the sterilized article, the dosimeter should be placed at a prescribed location. At the initial installation, the dosimeter is calibrated using the standard source and is periodically corrected.
60Co-γ-ray radiation sterilization method commonly used biological indicator for the short Bacillus spores (Spores of Bacillus pumilus).
4, the gas sterilization method
This law means a method of killing microorganisms with a gas formed by chemical disinfectants. Commonly used chemical disinfectants are ethylene oxide, gaseous hydrogen peroxide, formaldehyde, ozone (O3), etc., this method is applicable to the stability of the goods in the gas sterilization. When using the gas sterilization method, attention should be paid to the combustible explosive, teratogenicity and residual toxicity of the sterilized gas.
The most commonly used gas in this method is ethylene oxide, which is generally used in admixture with 80% to 90% of inert gas and in a high pressure chamber filled with sterile gas. The method can be used for medical equipment, plastic products can not be sterilized by high temperature sterilization items. Chlorine-containing items and substances that can adsorb ethylene oxide should not be sterilized by this method.
The use of ethylene oxide sterilization, sterilization cabinet temperature, humidity, sterilization gas concentration, sterilization time is an important factor affecting the sterilization effect. The following sterilization conditions are available:
Temperature 54 ℃ ± 10 ℃
Relative humidity 60% ± 10%
Sterilization pressure 8 × 105Pa
Sterilization time 90min
Sterilization conditions should be verified. Sterilization, the sterilization chamber into a vacuum, and then through the steam to the chamber to achieve the set temperature and humidity balance of the rated value, and then through the filtered and preheated ethylene oxide gas. During the sterilization process, the temperature, humidity, pressure, ethylene oxide concentration and sterilization time of the chamber should be closely monitored. Use biological indicators to monitor sterilization if necessary. The sterilization process of this method has a certain degree of difficulty, the entire sterilization process should be carried out under the supervision of skilled personnel. After sterilization, fresh air replacement should be taken to dissipate residual ethylene oxide and other volatile residues. And monitoring the ethylene oxide residues and reaction products in the sterilized article to demonstrate that it does not exceed the specified concentration and avoid toxicity.
In the case of sterilization with ethylene oxide, a leak test shall be carried out to confirm the airtightness of the sterilization chamber. When the sterilization procedure is confirmed, consideration should also be given to the effect of the arrangement of the packaging material and the sterilization chamber on the diffusion and penetration of the sterilized gas. Biological indicators generally use Bacillus subtilis spores (Spores of Bacillus subtilis).
5, filter sterilization method
This method utilizes the principle that bacteria can not pass through the dense pore filter to remove microorganisms in the gas or liquid. Commonly used in gas, heat instability of the drug solution or raw material sterilization.
The sterilization filter is used in the microporous membrane with uniform pore size distribution as the filter material, and the microporous membrane is divided into hydrophobic and hydrophobic. The filter material depends on the nature of the filter and the purpose of filtration. The diameter of the sterilization filter used in the production of the product is generally not more than 0.22 m. The pore size of the filter is defined by the retention of the filter to the microorganism, rather than the average pore size distribution. Therefore, the filter used for the final sterilization must be selected with a shut-off test to prove the sterilization grade filter. The adsorption of the filter on the filtrate should not affect the quality of the drug, no fiber off, disable the asbestos-containing filter. The user of the filter should be aware of the nature of the precipitate during the filtrate filtration process and assess the toxicity of the precipitate. The filter and filter should be cleaned before use and sterilized with high pressure steam or sterilized on-line. Replace the filter and replace the filter or replace the filter or replace the filter.
The aseptic guarantee during the filtration process is related to the initial biological load of the filtered liquid and the log reduction value of the filter. LRV means under the specified conditions. The number of microorganisms before filtration is filtered and the logarithmic value of the number of microorganisms filtered.
That is: LRV = lgN0-lgN
Where N0 is the number of microorganisms before sterilization.
N is the number of microorganisms after sterilization.
LRV is used to indicate the filtration efficiency of the filter. For filters with a pore size of 0.22 μm, the LRV of the effective filter area per 1 cm2 is required to be not less than 7. Therefore, when filtering sterilization, the total amount of filtered products should be controlled within the limits specified. To ensure that the filter sterilization effect, you can use two sterilization grade filter series filter, or in the filter before the filter with re-filter.
In the filter sterilization, the filter can not be the whole process of the key parameters (filter pore size and distribution, membrane integrity and LRV) to monitor. Therefore, before and after each filter sterilization should be the integrity of the test, that is, bubble point test or pressure maintenance test or gas diffusion flow test to confirm the filter in the sterilization filtration process effectiveness and integrity. The integrity of the test criteria comes from the relevant bacteria carrying experimental data. Sterilization filter should be used to verify the time, generally should not exceed one working day, or should be verified.
The biological indicator commonly used for filtration sterilization is Pseudomonas diminuta.
By sterilization method to achieve sterile products should be closely controlled by the cleanliness of its production environment, should be carried out in a sterile environment. Relevant equipment, packaging containers, stoppers and other items should be sterilized by appropriate means and prevent further contamination.
6, aseptic production process
Sterile production processes are methods that require the production of sterile formulations under aseptic conditions. Sterile dispensing and aseptic freeze drying are the most common sterile processes. The latter in the process must be used to filter sterilization method.
The aseptic production process should closely monitor the cleanliness of its production environment and should be operated in a sterile controlled environment. Relevant equipment, packaging containers, stoppers and other items should be sterilized by appropriate means. And to prevent contamination again.
The aseptic guarantee of aseptic production process should be verified by simulating the aseptic filling of the culture medium. In the production process, should closely monitor the production environment of the quality of sterile air, the quality of the operator, the aseptic nature of the items.
Sterile production processes should be verified on a regular basis. Including validation of ambient air filtration systems and simulation of medium filling test.