In non-sterile product manufacturing, the risk of microbial contamination is always a concern.
While products like creams, tablets, or lotions don’t always need to be sterile, they must still be free from harmful microorganisms. Small mistakes in microbiological practices can lead to big problems, including product recalls, safety issues, and regulatory penalties.
Today, we’re exploring some common microbiology pitfalls in non-sterile manufacturing and ways to avoid them in future practice.
1. Inadequate Cleaning Practices
One of the most common issues in non-sterile manufacturing is inadequate cleaning.
If equipment, surfaces, or environments aren’t properly cleaned, microorganisms can easily contaminate products. This issue typically occurs when the cleaning process is rushed, when indirect product contact areas are overlooked, or the validation is insufficient to ensure that the cleaning is effective – especially at those difficult to clean areas.
You can avoid this pitfall by implementing and validating cleaning procedures suited to the product, process and equipment. The validation should consider hold times, water quality, application technique and rinse requirements and should be routinely verified to ensure ongoing effectiveness.
2. Poor Microbiological Risk Assessments
Microbial risks are sometimes overlooked or under-assessed during the design and production phases. Without a solid microbiological risk assessment, companies may fail to identify contamination sources, such as water, raw materials, open processing or human handling.
You must always conduct a thorough microbiological risk assessment for each step in the manufacturing process.
It’s also good practice to regularly update the risk assessment when there are changes to the process. Scientific Fact sheets can be useful to support this risk assessment process.
3. Improper Deviation Handling
Microbiological excursions and deviations can be costly, especially if they’re not investigated properly. Ignoring the root cause of an issue can lead to further contamination and product safety and/or spoilage concerns.
Microbiologists can bypass this issue by developing a clear deviation protocol with specific action plans for investigation and corrective measures.
Every microbial issue should be thoroughly documented, and root cause analysis should be conducted, with appropriate corrective and preventative actions put in place to ensure the problem doesn’t happen again. Always learn from past mistakes!
4. Skipping Antimicrobial Efficacy Testing (AET)
For many non-sterile products, preservatives or antimicrobial agents are used to keep harmful microorganisms at bay during manufacture and routine consumer use through shelf life.
However, without proper Antimicrobial Efficacy Testing (AET), there’s no guarantee that these preservatives will remain effective over time.
Teams should conduct AET to ensure the antimicrobials remain effective throughout the shelf life, under various conditions, keeping products safe for use.
5. Inconsistent Sampling & Testing
A final key pitfall is inconsistent sampling and testing. Insufficient samples or outdated, unsuitable methods can let contamination slip through.
You can avoid this issue by developing a consistent sampling plan at critical control points based on risk assessment, using suitable microbiological testing methods and trending the resulting data to catch issues early.
Pharmig’s Upcoming Non-sterile Pharmaceutical and Personal Care Microbiology Session
On the 24th April, Pharmig is holding a virtual meeting on Non-Sterile Pharmaceutical and Personal Care Microbiology.
This online event covers topics, such as:
- Common audit citations in non-sterile products
- An approach to microbiological technical risk assessments for non-sterile manufacture – from a GSK perspective
- Cleaning validation considerations on microbiological aspects
- Deviation/investigation handling – common microbiological issues faced in Non-Steriles
- Antimicrobial efficacy testing (AET): benefits and pitfalls
- Blurring the lines: Learning from innovations in Non-Sterile QC Microbiology
Members can book for £360 and non-members £560.
Learn more and save your spot online here.
The Takeaway
Microbiology is vital in non-sterile manufacturing, and avoiding common pitfalls like poor cleaning, inadequate risk assessments, and inappropriate testing helps ensure product safety and quality.
Pharmig is also here to support your microbiology people, processes and practices. We’re a non-profit organisation established in 1991, representing individuals involved in microbiology within the pharmaceutical, healthcare, cosmetics, and NHS industries.
