Department that require filtration prior to final filling.

3. Responsibilities

• Production Chemist: To carry out the filtration process as per the batch record.
• Quality Assurance: To monitor the filtration process and ensure compliance with product specifications.
• Engineering Department: To maintain and validate filtration equipment as per preventive maintenance schedule.

4. Accountability

The Head – Manufacturing is accountable for the implementation and adherence to this SOP in the Gel Manufacturing department.

5. Procedure

5.1 Pre-Filtration Checks

1. Ensure the gel formulation is homogeneous and has passed in-process testing.
2. Verify cleanliness status of the filtration unit, hoses, and receiving vessel.
3. Ensure the filter is sterilized (if applicable) and assembled correctly as per equipment SOP.
4. Confirm that the required mesh size of the filter (typically 100–200 microns) is documented in the BMR.

5.2 Filtration Setup

1. Connect the filtration unit to the mixing vessel discharge valve using sanitized hoses.
2. Connect the outlet of the filtration unit to the receiving vessel or directly to the filling line hopper.
3. Clamp all hose ends securely and check for leakage.

5.3 Filtration Process

1. Start transferring the gel formulation through the filtration assembly.
2. Maintain appropriate flow rate and avoid turbulence to prevent air entrapment.
3. Monitor for signs of clogging, pressure increase, or filtration delay.
4. Record the start and end time of filtration.
5. Discard the first 100–200g of filtered gel or as defined in the BMR.

5.4 Filter Integrity and Disposal

1. After filtration, dismantle the filter unit under controlled conditions.
2. Inspect the filter for clogging or abnormal load.
3. Label and retain the used filter for QA review and visual confirmation.
4. Dispose of used filters as per SOP on Bio-waste Management.

5.5 Precautions

• Do not reuse filters without validation and QA approval.
• Avoid excessive filtration time to prevent shear stress or product degradation.
• Ensure filtered gel is not exposed to ambient conditions longer than defined hold time.

6. Abbreviations

• SOP: Standard Operating Procedure
• BMR: Batch Manufacturing Record
• QA: Quality Assurance

7. Documents

1. Filter Usage Log – Annexure-1
2. Filtration Equipment Cleaning Log – Annexure-2
3. Batch Manufacturing Record (BMR)

8. References

• Schedule M – Good Manufacturing Practices
• WHO TRS – Equipment Maintenance and Cleaning

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation	Jr. Production Chemist	QA Executive	Head – Manufacturing
Department	Gel Manufacturing	Quality Assurance	Manufacturing

11. Annexures

Annexure-1: Filter Usage Log

Includes filter type, mesh size, date/time, operator, and observations post-use.

Annexure-2: Filtration Equipment Cleaning Log

Tracks cleaning agent used, cleaning steps followed, operator initials, and QA verification.

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
01/05/2022	1.0	Initial release	GMP documentation	QA Head
02/06/2025	2.0	Updated with filter retention policy and mesh validation	Process optimization	QA Head