Standard Operating Procedure for Chromatography Skid Calibration in Biosimilar Manufacturing

Department	Biosimilars
SOP No.	SOP/BS/198/2025
Supersedes	SOP/BS/198/2022
Page No.	Page 1 of 9
Issue Date	04/05/2025
Effective Date	06/05/2025
Review Date	04/05/2026

1. Purpose

To establish a standardized procedure for the calibration of chromatography skid systems used in biosimilar downstream processing to ensure all critical sensors and control instruments meet GMP calibration requirements.

2. Scope

This SOP applies to all chromatography skids used in biosimilar purification processes including Protein A, ion-exchange, HIC, and polishing columns in GMP manufacturing areas.

3. Responsibilities

• Engineering: Perform calibration of instrumentation as per schedule.
• Production: Support in providing access to skids and verifying results.
• QA: Review calibration certificates, approve deviations, and control calibration schedules.

4. Accountability

The Head of Engineering and Head of Quality Assurance are accountable for ensuring that all chromatography skids are calibrated and maintained in validated condition.

5. Procedure

5.1 Preparation

1. Refer to the calibration master plan and verify due dates for chromatography skids.
2. Ensure equipment is shut down, depressurized, and LOTO (Lockout Tagout) is applied.
3. Gather certified reference standards and tools:
   • Flow standard (e.g., gravimetric setup)
   • Pressure calibrator
   • Conductivity and pH standard solutions
   • UV photometer calibrator

5.2 Calibration of Flow Sensor

1. Use a calibrated flow standard to simulate flow through skid pump line.
2. Compare displayed value with actual flow and adjust calibration factor if deviation exceeds ±5%.
3. Document results in Annexure-1.

5.3 Calibration of Pressure Transducers

1. Use a pressure calibrator to apply known pressure points (e.g., 0, 1, 2, 3 bar).
2. Check sensor output and ensure linearity across range.
3. Record all readings in Annexure-2. Acceptable deviation: ±1% of full scale.

5.4 pH and Conductivity Sensor Calibration

1. Disconnect in-line sensors and immerse in certified standard solutions (pH 4.0, 7.0, and 10.0).
2. Calibrate conductivity sensors using standards at 1.3 and 5.0 mS/cm.
3. Perform calibration through system HMI or local controller. Record in Annexure-3.

5.5 UV Detector Calibration

1. Run potassium dichromate solution or use a filter photometer to validate 280 nm absorbance accuracy.
2. Compare with reference standard. Acceptable deviation: ±0.005 AU.
3. Record findings in Annexure-4.

5.6 Calibration Labeling and Documentation

1. Affix calibration status label on each calibrated component with:
   • Calibration date
   • Due date
   • Technician initials
2. Update equipment history sheet and calibration tracking system.

5.7 Out-of-Tolerance (OOT) Handling

1. If sensor readings fall outside acceptance limits:
   • Tag as “Calibration Failed”
   • Notify QA and initiate deviation (Annexure-5)
   • Investigate potential impact on batches processed since last valid calibration

6. Abbreviations

• HIC: Hydrophobic Interaction Chromatography
• pH: Power of Hydrogen
• UV: Ultraviolet
• OOT: Out of Tolerance

7. Documents

1. Flow Sensor Calibration Log – Annexure-1
2. Pressure Sensor Calibration Log – Annexure-2
3. pH/Conductivity Sensor Log – Annexure-3
4. UV Calibration Report – Annexure-4
5. OOT Report – Annexure-5

8. References

• GAMP 5 – Good Automated Manufacturing Practice
• ICH Q10 – Pharmaceutical Quality System
• WHO TRS 961 – GMP for Biologics

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Flow Sensor Calibration Log

Date	Equipment ID	Setpoint (L/h)	Observed	Deviation	Status
04/05/2025	SKID-101	100	98.5	–1.5%	Pass

Annexure-2: Pressure Sensor Calibration Log

Date	Sensor ID	Setpoint (bar)	Observed	Status
04/05/2025	PRS-204	2.0	2.02	Pass

Annexure-3: pH/Conductivity Sensor Log

Date	Sensor ID	Standard	Observed	Status
04/05/2025	PHC-301	pH 7.00	6.98	Pass

Annexure-4: UV Calibration Report

Date	Detector ID	Expected AU	Observed AU	Status
04/05/2025	UV-022	1.000	0.998	Pass

Annexure-5: OOT Report

Date	Sensor ID	Parameter	OOT Description	Action Taken
03/05/2025	PHC-302	pH	Observed pH 6.2 instead of 7.0	Recalibrated, batch under review

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Enhanced UV calibration and OOT procedures	Internal audit compliance