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Standard Operating Procedure for Carbon Dioxide Sparging in Biosimilar Bioreactor Operations
| Department | Biosimilars |
|---|---|
| SOP No. | SOP/BS/106/2025 |
| Supersedes | SOP/BS/106/2022 |
| Page No. | Page 1 of 11 |
| Issue Date | 04/05/2025 |
| Effective Date | 06/05/2025 |
| Review Date | 04/05/2026 |
1. Purpose
To define the procedure for carbon dioxide (CO₂) sparging in bioreactor systems during biosimilar upstream processes, primarily for pH control and maintaining an optimal environment for cell culture growth.
2. Scope
This SOP applies to all production-scale and pilot-scale bioreactor systems equipped with pH control modules that utilize CO₂ sparging as a corrective mechanism within the biosimilar manufacturing facility.
3. Responsibilities
- Production Operator: Monitor and execute CO₂ sparging based on pH readings and process setpoints.
- Supervisor: Approve manual sparging actions and review sparging logs.
- Engineering: Maintain and calibrate flow meters and CO₂ delivery systems.
4. Accountability
The Head of Production is accountable for ensuring the proper control and documentation of carbon dioxide sparging activities to maintain pH within acceptable process limits.
5. Procedure
5.1 System Setup and Pre-Check
- Verify CO₂ gas line is connected to the bioreactor gas mixing panel.
- Ensure CO₂ supply is medical grade or as per approved specification.
- Check leak-free connections and confirm functionality of backpressure regulators.
5.2 Setting pH Control Strategy
- Set desired pH control band (e.g., 7.0 ± 0.2) in the SCADA/control system.
- Define control cascade: Acid (CO₂) as primary downtrend mechanism, base (e.g., NaOH) as uptrend.
5.3 Initiating CO₂ Sparging
- If pH rises above upper setpoint, automated CO₂ sparging is triggered through MFC (Mass Flow Controller).
- For manual sparging:
- Obtain supervisor approval.
- Initiate flow through CO₂ inlet line at 0.01–0.05 vvm based on vessel volume.
- Monitor pH response continuously during enrichment.
5.4 Monitoring and Documentation
- Log all CO₂ sparging events in Annexure-1 with time, duration, flow rate, and pH change.
- Ensure stable pH within control range is achieved within 15–30 minutes of sparging.
5.5 Post-Sparging Actions
- Close manual CO₂ flow valves and return control to automatic mode if overridden.
- Check for any foaming issues or DO shifts post-sparging.
- Notify Engineering if sparging is ineffective or erratic.
6. Abbreviations
- CO₂: Carbon Dioxide
- vvm: Volume of gas per volume of liquid per minute
- MFC: Mass Flow Controller
- SCADA: Supervisory Control and Data Acquisition
7. Documents
- CO₂ Sparging Log – Annexure-1
- CO₂ Flow Meter Calibration Record – Annexure-2
8. References
- ICH Q10 – Pharmaceutical Quality System
- FDA Guidance on Process Control and Monitoring (2023)
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: CO₂ Sparging Log
| Date | Batch No. | Initial pH | Flow Rate (vvm) | Start–End Time | Final pH | Performed By |
|---|---|---|---|---|---|---|
| 04/05/2025 | BS-215 | 7.3 | 0.03 | 10:10–10:30 | 7.0 | Sunita Reddy |
Annexure-2: CO₂ Flow Meter Calibration Record
| Equipment ID | Last Calibrated | Due Date | Status | Calibrated By |
|---|---|---|---|---|
| MFC-CO2-204 | 01/04/2025 | 01/10/2025 | OK | Ajay Verma |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 04/05/2025 | 2.0 | Added flow rate limits, alarm response, and calibration annexure | GMP process control update |