Standard Operating Procedure for Weight Variation Testing of Injectable Products
| Department | Sterile Injectable Manufacturing |
|---|---|
| SOP No. | SOP/SIM/072/2025 |
| Supersedes | SOP/SIM/072/2022 |
| Page No. | Page 1 of 13 |
| Issue Date | 18/06/2025 |
| Effective Date | 20/06/2025 |
| Review Date | 18/06/2026 |
1. Purpose
This SOP outlines the procedure for performing weight variation testing of filled injectable containers to ensure uniformity in dosage units and compliance with regulatory standards.
2. Scope
This SOP is applicable to all batches of injectable products filled in vials, ampoules, or prefilled syringes
manufactured in the sterile injectable manufacturing facility.
3. Responsibilities
- QC Analyst: Performs weight variation test as per this SOP.
- QA Officer: Ensures compliance to procedure and reviews test data.
- Production Officer: Supports sampling and ensures availability of required containers.
4. Accountability
The Head of Quality Control is accountable for ensuring that weight variation testing is performed and documented as per current GMP and pharmacopoeial guidelines.
5. Procedure
5.1 Sampling
- Collect 10 containers (vials/ampoules/syringes) randomly from the filled lot as per SOP for in-process sampling.
- Ensure containers are labeled appropriately and are free from external moisture.
5.2 Equipment Verification
- Ensure the analytical balance used for weighing is calibrated and within the valid calibration period.
- Record balance ID and calibration verification before use (Annexure-1).
5.3 Testing Method
- Weigh each filled container (Gross Weight) and record.
- Carefully remove the contents completely and clean the empty container.
- Weigh the empty container (Tare Weight) and calculate Net Weight = Gross Weight – Tare Weight.
- Record all readings in Annexure-2.
5.4 Acceptance Criteria
- Refer to applicable pharmacopeia (e.g., USP, IP) for acceptance limits, usually ±10% of label claim.
- If one or more units are outside acceptable limits, perform investigation as per deviation SOP.
5.5 Documentation and Review
- All test results must be reviewed and approved by QA.
- Attach test report to Batch Manufacturing Record for release.
6. Abbreviations
- SOP: Standard Operating Procedure
- QC: Quality Control
- QA: Quality Assurance
- IP: Indian Pharmacopoeia
- USP: United States Pharmacopoeia
7. Documents
- Balance Calibration Verification Log – Annexure-1
- Weight Variation Test Record – Annexure-2
- Deviation Report (if any) – Annexure-3
8. References
- USP <905> Uniformity of Dosage Units
- Schedule M – Good Manufacturing Practices
- WHO TRS No. 986 Annex 2
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | Manufacturing Executive | QA Executive | Head QA |
| Department | Production | Quality Assurance | Quality Assurance |
11. Annexures
Annexure-1: Balance Calibration Verification Log
| Date | Balance ID | Calibration Due Date | Checked By |
|---|---|---|---|
| 18/06/2025 | BAL-003 | 30/06/2025 | Sunita Reddy |
Annexure-2: Weight Variation Test Record
| Sample No. | Gross Weight (g) | Tare Weight (g) | Net Weight (g) | Remarks |
|---|---|---|---|---|
| 1 | 5.87 | 1.42 | 4.45 | Within Limit |
Annexure-3: Deviation Report
| Date | Deviation Details | Corrective Action | Reviewed By |
|---|---|---|---|
| 18/06/2025 | Sample 8 out of limit | Batch held, investigation initiated | Anil Jadhav |
Revision History
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial Issue | New SOP | QA Head |
| 18/06/2025 | 2.0 | Updated with Annexures and Criteria | Review Cycle | QA Head |