Standard Operating Procedure for Conducting Microbial Monitoring during Filling Process
| Department | Manufacturing |
|---|---|
| SOP No. | SOP/MFG/175/2025 |
| Supersedes | SOP/MFG/175/2022 |
| Page No. | Page 1 of 15 |
| Issue Date | 24/06/2025 |
| Effective Date | 25/06/2025 |
| Review Date | 24/06/2026 |
1. Purpose
This SOP defines the process for conducting microbial monitoring during the aseptic filling of sterile injectable products. The objective is to detect and control microbial contamination in critical manufacturing environments, ensuring product sterility and regulatory compliance.
2. Scope
This SOP is applicable to microbial monitoring
activities carried out during the aseptic filling of vials, ampoules, and prefilled syringes in ISO Class 5 (Grade A) and surrounding ISO Class 7 (Grade B) cleanroom environments.
3. Responsibilities
- Microbiology Analyst: To perform routine microbial sampling as per protocol.
- Manufacturing Operator: To cooperate during monitoring and prevent contamination.
- IPQA Officer: To oversee sampling integrity and environment conditions.
- QC Microbiology Supervisor: To ensure compliance with testing schedules and review results.
4. Accountability
The Head of Quality Control is accountable for ensuring that microbial monitoring activities are carried out effectively, deviations are investigated, and results are recorded and reported in a timely manner.
5. Procedure
5.1 Preparation
- Verify calibration and cleanliness status of environmental monitoring instruments (e.g., air samplers, settle plates, contact plates).
- Ensure media used (TSA plates, SDA plates) are within expiry and approved for use.
- Label all media with batch number, sample point ID, date, and time before sampling.
- Ensure sampling is performed by qualified microbiologists wearing sterile gowning.
5.2 Active Air Sampling
- Use a calibrated air sampler positioned in critical areas (e.g., near filling heads, stopper bowls).
- Set sample volume (usually 1000 L for Grade A areas) and run per standard protocol.
- Record data in the Environmental Monitoring Log (Annexure-1).
5.3 Passive Air Sampling (Settle Plates)
- Place TSA plates exposed for 4 hours in Grade A and B areas, covering representative zones (e.g., filling line, operator working bench).
- Avoid placing plates in areas with strong airflow or vibrations.
- Retrieve plates using aseptic technique and transfer to incubation area.
5.4 Surface Monitoring (Contact Plates)
- Monitor critical surfaces like:
- Gloved hands
- Filling machine parts
- Work surfaces
- Container closure contact areas
- Press contact plate gently for 10 seconds without movement.
- Replace lids and label with details.
- Document surface locations sampled (Annexure-2).
5.5 Personnel Monitoring
- Sample personnel gloves, sleeves, and chest area at the end of filling operation.
- Any personnel entering Grade A zones must be monitored at least once per shift.
- Record findings under Annexure-3.
5.6 Incubation and Result Interpretation
- Incubate TSA plates at 30-35°C for 48–72 hours and then at 20–25°C for an additional 72 hours.
- SDA plates used for fungal detection should be incubated at 20-25°C for 5–7 days.
- Count colony-forming units (CFUs) and compare to alert and action limits as defined by the site’s Environmental Monitoring Program.
- Record all observations and deviations in Annexure-4.
5.7 Action on Out-of-Limit Results
- If action limits are breached:
- Immediately notify QA and halt aseptic operation if applicable.
- Initiate deviation report and root cause investigation.
- Repeat sampling and increase frequency if required.
- Record incident in the Deviation Form (Annexure-5).
6. Abbreviations
- SOP: Standard Operating Procedure
- CFU: Colony Forming Units
- QC: Quality Control
- TSA: Tryptic Soy Agar
- SDA: Sabouraud Dextrose Agar
- IPQA: In-Process Quality Assurance
7. Documents
- Environmental Monitoring Log – Annexure-1
- Surface Monitoring Log – Annexure-2
- Personnel Monitoring Record – Annexure-3
- Microbial Count Log – Annexure-4
- Deviation Form – Annexure-5
8. References
- EU GMP Annex 1: Manufacture of Sterile Medicinal Products
- WHO TRS 961 Annex 6 – GMP for sterile pharmaceutical products
- USP <1116> – Microbiological Evaluation of Cleanrooms
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | Microbiology Executive | QA Executive | Head QA |
| Department | Quality Control | Quality Assurance | Quality Assurance |
11. Annexures
Annexure-1: Environmental Monitoring Log
| Date | Location | Method | CFU Count | Analyst |
|---|---|---|---|---|
| 24/06/2025 | Filling Hood | Active Air Sampling | 1 | Rajesh Kumar |
Annexure-2: Surface Monitoring Log
| Date | Surface Area | Location | CFU | Analyst |
|---|---|---|---|---|
| 24/06/2025 | Gloved Hand | Filling Line A | 0 | Sunita Reddy |
Annexure-3: Personnel Monitoring Record
| Date | Employee Name | Location | Glove CFU | Chest CFU |
|---|---|---|---|---|
| 24/06/2025 | Vikram Singh | Grade A – Filling Line B | 0 | 0 |
Annexure-4: Microbial Count Log
| Sample ID | Date | Location | Result | Limit | Status |
|---|---|---|---|---|---|
| SP-AIR-2025-015 | 24/06/2025 | Grade A Filling | 0 CFU | Action Limit = 1 CFU | Compliant |
Annexure-5: Deviation Form
| Date | Area | Deviation | Immediate Action | Approved By |
|---|---|---|---|---|
| 23/06/2025 | Filling Zone B | 2 CFU on Glove | Line Stopped, Re-gowning | QA Manager |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial Release | New SOP | QA Head |
| 24/06/2025 | 2.0 | Added updated alert limits and risk actions | Annual Review | QA Head |