Standard Operating Procedure for Distillation and Purification of Recovered Solvents in API Manufacturing
| Department | API Manufacturing |
|---|---|
| SOP No. | SOP/API/042/2025 |
| Supersedes | SOP/API/042/2022 |
| 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 validated procedure for the distillation and purification of recovered solvents to ensure their suitability for reuse in API manufacturing, thereby reducing waste and complying with GMP and environmental regulations.
2. Scope
This SOP applies to the distillation and purification operations for solvents recovered from production areas in the API manufacturing facility using in-house recovery systems.
3. Responsibilities
- Production Operator: Perform distillation activities and monitor process parameters.
- Engineering Department: Maintain distillation unit and ensure utility availability.
- QA Department: Verify documentation and approve purified solvent for reuse.
- QC Department: Analyze recovered solvent samples for quality testing.
4. Accountability
The Production Manager is accountable for implementation of the distillation process. QA Manager is responsible for ensuring compliance and authorizing the reuse of recovered solvents.
5. Procedure
5.1 Equipment and Setup
- Ensure availability of clean and calibrated distillation equipment including:
- Distillation vessel
- Condenser
- Receiver tank
- Thermocouple and pressure gauge
- Check utilities: heating system, chilled water circulation, and vacuum pump.
- Verify previous product residue has been removed (refer cleaning SOP).
5.2 Loading and Process Initiation
- Transfer used solvent from labeled drums to the distillation vessel using closed pipelines.
- Ensure solvent identity and quantity are recorded in the “Solvent Recovery Log” (Annexure-1).
- Start heating slowly while monitoring temperature and pressure.
- Collect solvent fractions as per boiling range data under atmospheric or vacuum conditions.
- Condensed purified solvent should be collected in pre-cleaned labeled containers.
5.3 Process Monitoring and Control
- Monitor and record:
- Distillation start time
- Jacket temperature
- Reflux ratio
- Vacuum level
- Ensure no over-boiling or contamination of the receiver.
- Stop distillation once residue volume or temperature exceeds control limits.
5.4 Quality Testing and Release
- Collect purified solvent samples and send to QC for testing:
- Purity
- Boiling point
- Color and odor
- Non-volatile residue
- Compare with respective solvent specifications.
- Label as “Purified Solvent – Approved for Reuse” or “Rejected” based on QC report (Annexure-2).
5.5 Documentation and Storage
- Enter all recovery data in the “Purified Solvent Inventory Register” (Annexure-3).
- Store approved solvents in designated solvent tanks or drums with status labels.
- Rejected solvents must be disposed of as per hazardous waste disposal SOP.
6. Abbreviations
- SOP: Standard Operating Procedure
- QA: Quality Assurance
- QC: Quality Control
- API: Active Pharmaceutical Ingredient
- ppm: Parts per million
7. Documents
- Solvent Recovery Log (Annexure-1)
- Purified Solvent QC Report (Annexure-2)
- Purified Solvent Inventory Register (Annexure-3)
8. References
- ICH Q7 – Good Manufacturing Practice Guide for APIs
- 21 CFR Part 211 – Subpart D & E
- WHO TRS 986 – Annex on Recovered Solvents
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Solvent Recovery Log
| Date | Solvent Name | Batch No. | Recovered Qty (L) | Start Time | End Time |
|---|---|---|---|---|---|
| 13/04/2025 | Ethyl Acetate | API-202506 | 120 | 08:00 | 11:30 |
Annexure-2: Purified Solvent QC Report
| Sample ID | Test | Result | Specification | Status |
|---|---|---|---|---|
| QC-SOL-025 | Purity | 99.8% | ≥99.5% | Pass |
Annexure-3: Purified Solvent Inventory Register
| Date | Solvent | Qty Approved (L) | Storage Tank/Drum ID | Label Status |
|---|---|---|---|---|
| 13/04/2025 | Ethyl Acetate | 120 | ST-11 | Approved for Reuse |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial SOP Release | New Equipment Installation | QA Head |
| 13/04/2025 | 2.0 | Added Annexures and QC Release Controls | Regulatory Compliance | QA Head |