The QC Manager is accountable for overseeing all microbial testing activities and ensuring the accuracy and reliability of test results. The Production Supervisor is responsible for ensuring that samples are collected at the correct stages and delivered for testing. The QA Manager ensures overall compliance with GMP and regulatory requirements.

5. Procedure

5.1 Pre-Test Preparation

1. Ensure that all required equipment, supplies, and test media are available and sterile before initiating testing. This includes petri dishes, incubation chambers, and appropriate growth media for microbial analysis (e.g., Agar media, Sabouraud Dextrose Agar, etc.).
2. Review the product batch record for the cream formulation to be tested. Confirm the sampling plan, test specifications, and any regulatory requirements.
3. Ensure that all testing areas are clean and disinfected. Use proper aseptic techniques to avoid contamination during the test process.
4. Verify that all personnel involved in the testing are trained and qualified to perform microbial testing in accordance with GMP standards.

5.2 Sampling Procedure

1. Identify the appropriate stage of production for sampling (e.g., after mixing, before packaging). Ensure that samples are collected from different batches or production runs to ensure representativeness.
2. Collect the required amount of cream from the batch using a sterile tool, such as a sterile spatula or pipette, depending on the consistency of the formulation.
3. Transfer the sample to a sterile container, label it with the batch number, sample date, and sampling point, and transport it to the QC laboratory for microbial analysis.
4. Ensure that samples are transported under proper conditions (e.g., refrigerated or at ambient temperature, as specified in the sampling protocol) to maintain their integrity until testing.

5.3 Microbial Testing Procedure

1. In the QC laboratory, transfer the sample to a suitable dilution buffer if needed (e.g., sterile phosphate-buffered saline) for microbial testing.
2. Perform the microbial analysis as per the testing method specified for cream formulations. This may include testing for total aerobic count (TAC), yeast and mold count, and specific pathogens such as Staphylococcus aureus, Escherichia coli, and Salmonella.
3. For microbial enumeration, plate the diluted samples onto appropriate agar plates, such as Plate Count Agar (PCA) for total bacterial count or Sabouraud Dextrose Agar for yeast and mold count.
4. Incubate the plates at the recommended temperature (e.g., 30–35°C for bacteria, 20–25°C for molds and yeasts) for the specified period (e.g., 48 hours).
5. Count the number of colonies formed on each plate after incubation. Record the results in the Microbial Testing Log (Annexure-1), noting the type of microorganisms present and the count.

5.4 Interpretation of Results

1. Compare the results with the established acceptance criteria for microbial contamination. For example, cream formulations should not exceed the specified limits for total aerobic count or specific pathogens, as outlined in regulatory guidelines or the company’s specifications.
2. If the microbial counts exceed the acceptable limits, flag the batch for investigation. Investigate the source of contamination, including potential cross-contamination during production or sampling errors.
3. If necessary, initiate a root cause analysis and corrective actions. Re-test the formulation after corrective actions have been implemented, such as cleaning or adjusting production processes.

5.5 Post-Test Activities

1. Document all microbial testing results, including any deviations, corrective actions, and re-testing results, in the Microbial Testing Log (Annexure-1).
2. Ensure that all test records are reviewed and approved by the QC Manager and stored for traceability and regulatory compliance.
3. If the batch passes the microbial testing, proceed with the next stage of production (e.g., packaging or distribution). If the batch fails, initiate appropriate corrective actions and prevent the batch from being released for use or sale.

5.6 Documentation and Record-Keeping

1. Ensure that all records related to microbial testing, including the Microbial Testing Log (Annexure-1), are accurately filled out and stored securely.
2. Maintain all testing records for a minimum of two years or as per regulatory requirements.
3. Ensure that records are reviewed by the Quality Assurance team for compliance with GMP and regulatory standards.

6. Abbreviations

• GMP: Good Manufacturing Practices
• QC: Quality Control
• QA: Quality Assurance
• PPE: Personal Protective Equipment
• CoA: Certificate of Analysis

7. Documents

1. Annexure-1: Microbial Testing Log

8. References

• Good Manufacturing Practices (GMP) Guidelines – 21 CFR Part 211
• International Conference on Harmonisation (ICH) Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• Pharmacopeial Monographs for Microbial Limits in Cosmetics (USP/NF)

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Microbial Testing Log

Batch Number	Sample ID	Sampling Date	Test Results	Operator
12345	S-001	21/01/2026	Total Count: 200 CFU/g, Yeast and Mold: Pass	John Doe

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/03/2024	1.0	Initial Version	New SOP Creation	QA Head
01/03/2025	2.0	Format Revision and Updates	Standardization of Document	QA Head