Standard Operating Procedure for Inspection of Granule Flow Properties During Compression
| Department | Quality Control |
|---|---|
| SOP No. | SOP/TAB/131/2025 |
| Supersedes | SOP/TAB/131/2022 |
| Page No. | Page 1 of 6 |
| Issue Date | 01/03/2026 |
| Effective Date | 06/03/2026 |
| Review Date | 01/03/2027 |
1. Purpose
To define the procedure for inspecting the flow properties of granules during the compression process to ensure uniform and efficient tablet formation.
2. Scope
This SOP applies to the inspection of granule flow properties during tablet compression. It ensures that granules have appropriate flow characteristics for consistent tablet compression and quality.
3. Responsibilities
- Quality Control (QC): Responsible for inspecting granule flow properties and ensuring that they meet the required specifications for uniform tablet compression.
- Compression Operator: Responsible for adjusting machine parameters to ensure that the granules flow properly during the compression process.
- Quality Assurance (QA): Ensures that the granule flow inspection procedure is followed according to this SOP and reviews results for compliance with quality standards.
4. Accountability
The QC Manager is accountable for ensuring that the granule flow properties are inspected accurately during the compression process. The QA Manager is responsible for reviewing and ensuring compliance with the inspection results.
5. Procedure
5.1 Granule Flow Property Assessment
- Inspect the granules before and during the compression process to evaluate their flowability, which is crucial for consistent tablet formation.
- Granules should be free-flowing without clumping, bridging, or poor flow, which could cause irregular tablet weight or formation issues.
5.2 Flow Property Testing Methods
- Perform a flowability test using methods such as the “angle of repose” test, “Hausner ratio,” or “Carr index” to evaluate the granule’s flow characteristics.
- For the angle of repose test:
- Place the granules in a funnel and allow them to flow freely onto a flat surface.
- Measure the angle formed between the surface of the pile and the horizontal plane. A typical acceptable angle of repose range for granules is 25°–35°.
- For Hausner ratio or Carr index:
- Calculate the bulk and tapped density of the granules to assess flowability. The Hausner ratio should ideally be between 1.2 and 1.5 for good flow.
- The Carr index should ideally be below 15% for good flow.
5.3 Sample Collection
- Collect representative samples of granules at regular intervals during the granulation process, typically every 100 grams of granules produced or after each major granulation stage.
- Ensure that the sample is representative of the entire batch by collecting from different locations (top, middle, and bottom of the batch).
5.4 Monitoring and Adjustments
- Monitor the flow properties during the compression process. If any issues, such as poor flow or clogging, are detected, adjust the compression machine settings or the granulation process.
- For poor flow, consider adjusting the granule size distribution, moisture content, or binder levels in the granulation process.
- If issues persist, perform additional granulation to optimize flow properties.
5.5 Documentation
- Record all granule flow property results, including test methods, values, and any corrective actions taken, in the batch record (Annexure-2).
- Document any deviations or corrective actions in the deviation report (Annexure-1).
- Ensure that all records are signed, dated, and reviewed by QA for compliance.
5.6 Acceptance Criteria
- Granules should exhibit good flowability with an angle of repose between 25° and 35° and a Hausner ratio between 1.2 and 1.5.
- If the flow properties fall outside the specified range, corrective actions should be taken, such as modifying the granulation parameters or reprocessing the granules.
5.7 Post-Compression Actions
- Once the granule flow properties are acceptable, proceed with the compression process and continue to monitor flow properties as needed during subsequent batches.
- Ensure that all monitoring equipment is cleaned and calibrated as required after each inspection.
6. Abbreviations
- SOP: Standard Operating Procedure
- GMP: Good Manufacturing Practice
- QC: Quality Control
- QA: Quality Assurance
- API: Active Pharmaceutical Ingredient
7. Documents
- Batch Record (Annexure-2)
- Deviation Report (Annexure-1)
8. References
- USP <1174> – Powder Flowability Testing
- 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
- European Pharmacopoeia (EP) – Granule Flow Properties
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Deviation Report
| Deviation Date | Batch Number | Deviation Description | Corrective Action | Responsible Person |
|---|---|---|---|---|
| 15/12/2025 | Batch 001 | Poor granule flow resulting in uneven tablet weight | Adjusted granule binder content and compression settings | Jane Doe |
Annexure-2: Batch Record
| Sample Number | Flow Property Test Result | Action Taken |
|---|---|---|
| Sample 1 | Good flowability (Hausner ratio 1.3) | Accepted |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial Version | New SOP Creation | QA Head |
| 01/02/2025 | 2.0 | Updated flow testing methodology | Improved testing procedure | QA Head |