Sterility testing methods

Sterility testing Methods Antimicrobial agents 8 Further reading... 

The method for sterility testing of (product name) USP is manufacturing site SOP and the microbiological sterility method validation summary report is provided in (provide reference attachment number). The USP bacteriostasis/fungistasis test was performed to validate the sterility test method... 

Validation of membrane filtration and direct inoculation sterility test methods... 

The purpose is to develop a guideline to validate the efhcacy of the sterility test method for a specihc product or material. The similarity of the validation approach with the other pharmaceutical manufacturers shall be considered coincidental due to the similarity of operations and the nature of the work. 

Review sterility test method and handling of samples. 

Microbial ChaUenge/Product Sterility Test Methods. There are really two types of microbial barrier test those performed on materials and those performed on whole packages. Microbial barrier... 

It is necessary to estabUsh a criterion for microbial death when considering a sterilization process. With respect to the individual cell, the irreversible cessation of all vital functions such as growth, reproduction, and in the case of vimses, inabiUty to attach and infect, is a most suitable criterion. On a practical level, it is necessary to estabUsh test criteria that permit a conclusion without having to observe individual microbial cells. The failure to reproduce in a suitable medium after incubation at optimum conditions for some acceptable time period is traditionally accepted as satisfactory proof of microbial death and, consequentiy, stetihty. The appHcation of such a testing method is, for practical purposes, however, not considered possible. The cultured article caimot be retrieved for subsequent use and the size of many items totally precludes practical culturing techniques. In order to design acceptable test procedures, the kinetics and thermodynamics of the sterilization process must be understood. 

In all antiseptic testing, it is recognized that skin and mucous membranes to which products ate appHed cannot be disinfected or sterilized but it is possible to significantly reduce the population of transient and resident pathogenic bacterial flora. AH in vivo test methods requite a deterrnination of the bacteria on the skin before and after treatment. Because of the normal variation in bacterial population of the skin of different people, a number of people must be tested in order to make a statistical analysis of the results. Different parts of the body are used for different tests. In aH of the tests the details of the protocol ate extremely important and must be strictly adhered to in order to obtain reproducible results. 

There are three alternative methods available when conducting sterility tests. 

Breeze A.S. Simpson A.M. (1982) An improved method using acetyl-coenzyme A regeneration for the enzymic inactivation of aminoglycosides prior to sterility testing. JApplBacteriol, 53, 277-284. 

The purpose of a sterility test is to determine the probable sterility of a specific batch. The USP lists the procedural details for sterility testing and the sample sizes required [1], The USP official tests are the direct (or culture tube inoculation) method and the membrane filtration method. 

Currently the main application of interest for parametric release is to replace the sterility test as a control method in appropriate cases (given the limited value of that test to predict sterility assurance due to statistical considerations, although it is also pointed out that a sterility test provides a final opportunity to identify a major failure, although other means should provide a more reliable way of detecting such failures). The concept is applicable to well-founded methods of sterilization where the product stability is known and development data have identified the critical process parameters. The measured parameters should be such as to ensure that correct processing of the batch provides sufficient assurance that the sterility assurance level intended has been achieved. 

Water system Cleaning practices Computer validation Process validation Test methods validation Sterilization procedures Stability evaluation... 

The sterility test is applicable for determining whether drug substances, preparations, or other pharmacopeial articles are sterile as defined by the compendial method. A satisfactory result only indicates that no contaminating microorganisms have been found in the sample examined rmder the conditions of the test. Therefore, the result is a function of the efficiency of the adopted sampling plan. Compendial references to sterility testing include USP 24 Chapter (71) Sterility Tests the Ph. Eur. 3rd ed.. Biological Tests 2.6.1, Sterility and the JP Xlll 45, Sterility Test. 

The USP 24 General Notices state that alternative methods may be used to determine that products comply with the pharmacopoeial standards for the advantages in accuracy, sensitivity, precision, selectivity, adaptability to automation or computerized data reduction, or any other special circumstances. Such alternative or automated methods shall be validated However, when disputed, the compendial method is conclusive as it is the official or referee test. In addition, USP Chapter (61) Microbial Limit Tests states that automated methods may be substituted provided they are validated and give equivalent or better results, whereas USP Chapter (71) Sterility Tests states that alternative procedures may be employed to demonstrate that an article is sterile, provided the results obtained are at least of equivalent reliability. 

USP 24 Testing Chapters (51) Antimicrobial Effectiveness Testing, (61) Microbial Limit Tests and (71) Sterility Tests, United States Pharmacopeial Convention, Inc., Rockville, MD, 2000. USP 24 Informational Chapters (1116) Microbiological Evaluation of Clean Rooms and other Controlled Environments, (1111) Microbiological Attributes of Pharmaceutical Articles, (1151) Pharmaceutical Dosage Forms, (1225) Validation of Compendial Methods, and (1231) Water for Pharmaceutical Purposes, United States Pharmacopeial Convention, Inc., Rockville, MD, 2000. 

The sterilizer utilization list and the following OQ test requirements summary will be utilized to determine the products assigned to the sterilizer that shall be subjected to the type and number of test function runs required to establish overall sterilizer qualification or validation. The test function subsections shall include test objectives, test methods and acceptance criteria, as follows. 

Investigate sterility test procedures and room sanitation and sterilization methods to eliminate cause. 

The main objective of validation of an analytical procedure is to demonstrate that the procedure is suitable for its intended purpose. The procedures presented in this SOP provide basic guidelines for the validation of methods for microbiological assay, estimation of the number of microorganisms, detection of indicators of objectionable microorganisms, validation of preservative efficacy testing, and validation of the sterility testing and endotoxin test (LAL test). 

In a test group the product is subjected to the neutralization method, and then a low level of challenge microorganism (less than 100 cfu) is inoculated for recovery. In a peptone control group the neutralization method is used with peptone or diluting fluid A (Sterility test 71) as the test solution. In a viability group the actual inoculum is used without exposure to the neutralization method. 

It is assumed in the direct transfer method under sterility tests that the recovery medium will allow for growth of all surviving microorganisms. The liquid medium in that test must serve to neutralize any antimicrobial properties of the test solution and to support the growth of the microorganisms. The treatment groups described above (antimicrobial neutralization for recovery on agar medium) can be used for validation of the recovery method, with the proportions of product and recovery medium varied to achieve adequate neutralization. 

Bioburden testing is performed on components prior to steam sterilization as verification that the sterilization parameters are sufficient for sterilization of components. The method for determining the bioburden level of components is included in the manufacturing site standard test method. For product component bioburden summary, refer to (provide reference attachment number). 

Container closure integrity test methodology is per (specify standard test method number). All units for container closure integrity testing are processed using routine production parameters for preparation. Worst-case parameters are used for sterilization. 

Sterility testing of (specify name) USP microbiological sterility method validation summary report... 

Before tests for sterility for any product are initially carried out, it is necessary to demonstrate the validity of the test method used by recovery of a small number of microorganisms in the presence of the product. 

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