Abstract
Many methods and tools used in the modern pharmaceutical microbiology laboratory were derived in the nineteenth century. The methods may not seem to be complicated, but are effective and still used. For example, tools such as agar-based media, petri dishes, glass pipettes, streaking methods, Bunsen burners, and microscopes are still in use and perform well.
There is a continuing expectation for what and how to investigate aberrant results obtained in the laboratory. (McCullough and Moldenhauer, 2015)
The Barr Decision (Barr, 1993) has caused pharmaceutical companies to have a totally new outlook on the treatment of out-of-specification (OOS) data. As part of this court decision it was stated that any OOS result requires a failure investigation. The type of error encountered determines the level of investigation needed. Lesser investigation is required for a laboratory investigation but more is required for process investigations. All of the investigations must be thoroughly documented. (Longwell, 2015)
Following the issuance of this legal decision, it was necessary to determine how this decision affects microbiological test results. FDA issued a Guidance for Out-of–Specification Results (FDA, 2006). This guidance specifically exempts microbiological testing from applicability but many of the principles in this guidance are still applicable to microbiological testing. The investigation starts with a determination of whether laboratory error has occurred. If not, it proceeds to a full investigation of the process. Some of the items recommended for the supervisor to determine include (FDA, 2006): • Analysis of the analysts knowledge and performance of the test procedure (correctly).
- Examination of the raw data obtained in the analysis for anomalous or suspect information.
- Verification that calculations used on raw data were performed correctly, are scientifically sound, appropriate and whether changes (unauthorized)
- Determining whether the instrument was performing correctly, within qualified parameters.
- Verifying that the appropriate reference standards, solvents, reagents, and other solutions used were evaluated and met the quality requirements.
- Evaluation of the test method’s performance to ensure it is operating as qualified.
- That the investigation is fully documented and all records are maintained.
- Ideally, each investigation should lead to a discovery or the root cause of a problem or a potential root cause. Unfortunately, this can be a bit more difficult to do for many microbiological investigations.
Before the Investigation – Do You Have Systems in Place to Support Your Investigations?
There are many different types of microbial contamination that can occur in pharmaceutical manufacturing. Some of the sources include: water, raw materials, excipients, in-process materials and samples, the manufacturing process, the product itself, the environment and the like. As such, there is no one size fits all investigation.
This is not the case for non-sterile or low bioburden products. Not all contamination is a bad thing and it is important to understand many things about the product prior to deciding on the type of investigation and the concerns of the investigation.
According to the bioburden control monograph in USP <1115> (USP, 2015) the factors that contribute to nonsterile product bioburden include: facility design and maintenance, tools and utensils, influences from adjacent areas, seasonal effects, process and cleaning water, facility housekeeping/sanitization, nonproduct contact equipment, validation, product and material flow, personnel gowns and hygiene, primary packaging components, raw materials, active pharmaceutical ingredients, manufacturing and filling processes, equipment cleaning and maintenance, personnel practices and training, storage conditions, HVAC, equipment design, and personnel flow. With a list this long, the investigation could become overwhelming without a method to prioritize and organize the areas of focus. As such, it becomes important for you to know about the types of microorganisms that are of concern to the product and the patient, dependent upon the route of administration used.
Detailed risk assessments should be conducted for the types of products and potential contamination at your site. The information gained from these risk assessments can become extremely helpful in conducting the investigation and determining appropriate actions to take. More information on this topic is provided in USP <1115>. (USP, 2015)
Another useful tool is to maintain good microbial trending records for your facility. Can your records identify the likelihood that this is a routine contamination or something unusual? Do you have reports that indicate data is getting better or worse? Are you looking at the effectiveness of your cleaning? These types of reports can become invaluable in the investigation process.
Do you maintain a microorganism identification program? What is the normal flora in your facility? When you get a new organism, what actions do you take? Without programs like these, you will have a lot more difficulty in determining how to respond to your investigation.
The Investigation Process
The investigation is conducted in a two-step process: step one (the laboratory investigation) is to determine whether the result obtained (indicating a problem) is a valid result or not and step two (process investigation) is investigating the process, if the result obtained in step one is valid.
The Laboratory Investigation
The key determination in this part of the process is whether or not the aberrant laboratory results are true aberrations. You need to scrupulously investigate the sample and its history. Some of the typical considerations include, but are not limited to:
- Did you use the correct method to collect the sample?
- Were the reagents, media, and other supplies released by quality assurance and used within their expiration dates?
- Did you follow the procedure exactly as written?
- Was there other contamination in the laboratory during the time you were testing the sample?
- Do you have supporting environmental data for the laboratory?
- What type of housekeeping practices are used in the laboratory?
- Did anything happen to the sample in route to the laboratory, e.g., dropping, opening the plate, etc.?
- How long did the sample sit before testing and where did it reside?
- Was the analyst properly training and qualified to perform the test?
- Was all of the equipment used within its validated or qualified requirements?
- Were all the instruments calibrated?
- And so forth.
During this part of the investigation, you are looking for incontrovertible evidence that the only reason for the aberration was something that occurred in the laboratory. Unless this can be shown, the investigation proceeds to an investigation of the manufacturing process. If the error can be shown to be due to the laboratory, the sample result is considered invalid. In either case, the investigation should be well documented and approved by quality assurance.
The Manufacturing Process Investigation
The FDA provided a template for conducting investigations for sterility test failures in its Aseptic Processing Guidance (FDA, 2004). While indicated for a specific type of investigation, this template has been successfully used to support many types of microbial investigations.
Key considerations in this investigation template include the following (FDA, 2004):
- The identification of the contaminating microorganism(s)
An accurate identification can be useful in determining the potential source of the contamination and provide a basis of information for comparison of contamination sites found. It is important to identify if the organism is found only in the laboratory or also in the production environment. - Record of Laboratory Tests and Deviations
It is useful to have trending reports for the laboratory data so that the laboratory can be considered the source of the contamination or whether it is likely to be the production site. When these records are not maintained, extensive investigation is required to obtain this data and it can seriously slow down the investigation. It is important that laboratory deviations have been handled and documented properly. A high incidence of laboratory deviations should be an indication of other issues in the laboratory, e.g., insufficient training, poor GMP practices and the like. When a laboratory has a good record it reduces the likelihood that the contamination came from the laboratory. The converse however is not automatically true. - Monitoring of the Production Area
Trending data should be reviewed to determine whether the contaminants found have been isolated in the production area. It is important to look not only at the area of interest but also the surrounding areas. You may wish to look at multiple days, lots and shifts. It is useful to look for similar sources of contamination also. For example if you isolated a Gram-negative microorganism, you may wish to look at all the Gram-negative organisms isolated before ruling out a source of contamination. When little contamination is found in the area it can be more difficult to determine the source of contamination and extra sampling of areas may be necessitated. You should look at both long and short term trending data. - Monitoring Personnel
Personnel monitoring data should be reviewed and analyzed. In some cases, personnel that perform specific tasks may be more likely to have an impact on contamination events than others. Part of this review should include employee training records, including those for gowning and history of deviations. - Product Pre-Sterilization Bioburden
It is useful to look at the historical data for product bioburden testing. The identity of organisms as well as the actual counts obtained should be considered for the affected time periods. Again, looking at similar organisms may also be useful. - Production Record Review
Review the complete batch records to determine if failures or abnormal occurrences took place. Trending of data for utilities and the like, e.g., performance, aberrations and the like can be useful. - Manufacturing History
Has this product line had similar contamination problems in the past? Is there a history of certain types of equipment failures? Is the product hard to process? These types of review can help lead to a source of the contamination.
The goal of this process is to find a root cause for the contamination or a potential root cause. Unfortunately, many microbial investigations do not lead to a definitive root cause being found.
Conclusion
Once the source of the contamination has been found or believed to be identified, the next step is to evaluate the effect of the contamination on the process. The effect will differ based upon the type of product and whether the product is/is not sterile. The risk assessments conducted and knowledge of the product, its route of administration, and the type of patients who receive the product becomes critical in determining batch disposition. Conducting the investigation is only step one of the overall process.
References
- Barr (1993) UNITED STATES of America, Plaintiff, v. BARR LABORATORIES, INC., et al., Defendants. Downloaded from http://www.leagle.com/decision/19931270812FSupp458_11169.xml/U.S.%20v.%20BARR%20LABORATORIES,%20INC. on February 2, 2015.
- FDA (2004) Guidance for Industry Sterile Drug Products Produced by Aseptic Processing — Current Good Manufacturing Practice. U.S. Department of Health and Human Services. Food and Drug Administration Center for Drug Evaluation and Research (CDER). Center for Biologics Evaluation and Research (CBER). Office of Regulatory Affairs (ORA).
- FDA (2006) Guidance for Industry: Investigating Out-of-Specification (OOS) Test Results for Pharmaceutical Production. U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER). Pharmaceutical CGMPs.
- Longwell, A. (2015) United States of America v. Barr Labs, Inc. 812 F. Supp 458, 3/30/93 GMP Lessons From a Federal Judge. Downloaded from http://fdclaw.com/cases/gmp/ on February 2, 2015.
- McCullough, K. and Moldenhauer, J. (2015) Chapter 1 Introduction in Microbial Risk and Investigations. McCullough, K. and Moldenhauer, J., Eds. Parenteral Drug Association (PDA) and Davis Heathcare International (DHI). Bethesda, MD.
- USP (2015) <Bioburden Control of Nonsterile Drug Substances and Products>. United States Pharmacopeia 38/National Formulary 33. Rockville, MD. P. 1185.
Author Biography
Jeanne Moldenhauer is a senior quality assurance/regulatory affairs professional with extensive background in the development and management of a variety of sterilization and validation processes in the healthcare industry. She has extensive practical background in both the manufacturing facilities and corporate operations. Jeanne is currently the vice-president of Excellent Pharma Consulting, Inc. Jeanne serves as a senior quality and regulatory consultant. As part of this position she serves as the microbiology and/or regulatory consultant for several companies. She acts as a regulatory consultant for several rapid microbiology companies. Additionally, she consults on various areas of quality management and quality engineering, microbiology, rapid microbiology, sterility assurance, aseptic processing, risk assessment, compliance, and regulatory submissions. Jeanne works with compounding pharmacies and the equipment for use in these pharmacies to provide guidance on implementation of USP <797> as well as microbiology and aseptic support for regulatory submissions. She also works with regulatory submissions in the device, drug, and biologics areas.