Standard Operating Procedure for In-Process Filtrate Clarity Testing in API Manufacturing
| Department | API Manufacturing |
|---|---|
| SOP No. | SOP/API/099/2025 |
| Supersedes | SOP/API/099/2022 |
| Page No. | Page 1 of 10 |
| Issue Date | 13/04/2025 |
| Effective Date | 15/04/2025 |
| Review Date | 13/04/2026 |
1. Purpose
To define a standardized procedure for performing clarity testing of filtrates collected during filtration steps in API manufacturing, ensuring absence of particulate matter and confirming filtration integrity.
2. Scope
This SOP applies to all visual clarity checks carried out during intermediate and final filtration steps in API manufacturing processes.
3. Responsibilities
- Production Chemist: Collect samples for clarity testing and perform initial
visual observation.
QC Analyst: Review and document results of clarity observations and initiate re-filtration if required.
QA Officer: Approve clarity test reports and verify documentation accuracy.
4. Accountability
The Production Head is accountable for implementing clarity checks. QA Head is responsible for ensuring compliance and traceability of the filtration monitoring process.
5. Procedure
5.1 Sampling
- Collect ~50 mL of filtrate sample in a clean, transparent glass beaker or vial immediately after filtration.
- Ensure the sample is free from any contamination introduced during collection.
5.2 Visual Clarity Observation
- Place the beaker against a white and black background under adequate illumination (minimum 1000 lux).
- Observe for any visible particulate matter, turbidity, or haziness.
- If necessary, use a flashlight at a 45-degree angle to enhance visibility of suspended matter.
- Compare sample with a standard blank (solvent or clean filtered water) for reference.
5.3 Acceptance Criteria
- The filtrate must appear clear and free from any suspended particles or haziness.
- In case of visible particles:
- Repeat filtration using the same or finer filter media.
- Record deviation and escalate to QA if multiple occurrences are noted.
5.4 Documentation
- Record clarity test results in the Filtrate Clarity Logbook (Annexure-1).
- Include:
- Date and time of test
- Batch number
- Filtration stage
- Observation (Clear / Hazy / Particulate matter)
- Initials of observer
- Attach photographic evidence if required by QA or SOP deviation process.
6. Abbreviations
- SOP: Standard Operating Procedure
- QA: Quality Assurance
- QC: Quality Control
- BMR: Batch Manufacturing Record
7. Documents
- Filtrate Clarity Logbook (Annexure-1)
- Batch Manufacturing Record
- Deviation Form (if applicable)
8. References
- ICH Q7 – Good Manufacturing Practice for APIs
- 21 CFR Part 211 – US FDA GMP
- WHO TRS 986 – GMP Guidelines
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Filtrate Clarity Logbook
| Date | Batch No. | Filtration Stage | Observation | Performed By | Remarks |
|---|---|---|---|---|---|
| 13/04/2025 | API-20250413 | Post-Reaction Filtration | Clear | Complies |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial Release | Process Monitoring SOP | QA Head |
| 13/04/2025 | 2.0 | Added flashlight and photographic comparison techniques | GMP Enhancement | QA Head |