Standard Operating Procedure for Ensuring Accuracy of In-Process Weight Checks
| Department | In-Process Control |
|---|---|
| SOP No. | SOP/IPC/171/2025 |
| Supersedes | SOP/IPC/171/2022 |
| Page No. | Page 1 of 14 |
| Issue Date | 25/06/2025 |
| Effective Date | 27/06/2025 |
| Review Date | 25/06/2026 |
1. Purpose
The purpose of this SOP is to define a systematic procedure to ensure the accuracy of in-process weight checks during the manufacturing of sterile injectable products. It helps to maintain compliance with GMP regulations and ensure consistency and quality of the final
product.
2. Scope
This SOP applies to all manufacturing processes involving filling, sealing, and labeling of injectable products in vials, ampoules, and prefilled syringes where weight verification is part of in-process control (IPC) at the sterile manufacturing facility.
3. Responsibilities
- Manufacturing Operator: To perform weight checks as per the batch record and SOP.
- IPQA Officer: To verify, record, and ensure compliance of weight check limits and frequency.
- QA Executive: To review the weight check documentation and initiate necessary deviation reports for any non-conformity.
4. Accountability
The Head of Quality Assurance is accountable for implementation and compliance with this SOP across sterile manufacturing areas.
5. Procedure
5.1 Preparation for Weight Checks
- Ensure the balance or check weigher is calibrated and verified before use. Refer to the Balance Calibration Log (Annexure-1).
- Use only identified and labeled balances for IPC weight checks.
- Verify the equipment ID and location before initiating weight checks.
5.2 Execution of Weight Checks
- Collect a predefined number of units (e.g., 10 vials) from the filling line every 30 minutes or as per the BMR.
- Place each unit individually on the balance and record the gross weight.
- Refer to the Tare weight of the container (vial, ampoule, or syringe) as per specification.
- Calculate the net fill weight: Gross weight – Tare weight = Net weight.
- Compare the net weight against the approved specification/range stated in the product specification sheet.
- Record all weights in the Weight Verification Log (Annexure-2).
5.3 Acceptance Criteria
- Net weight must fall within ±5% of labeled fill weight unless otherwise specified.
- If any unit is found out of specification, perform a second check with another set of 10 units.
- If failure is confirmed, immediately inform Production and QA. Initiate deviation and investigate root cause.
5.4 Frequency of Checks
- Initial check: Before batch filling starts (trial run verification).
- Routine checks: At predefined intervals during filling.
- Post-run check: After filling operation is completed.
- Additional checks: If any abnormality or deviation is observed in the line or weight trends.
5.5 Handling Out-of-Limit Results
- Segregate the affected batch quantity filled since the last satisfactory check.
- Review line parameters (nozzle clogging, vacuum sealing, equipment speed, air pressure, etc.).
- Document all observations and findings in Deviation Report Form (Annexure-3).
- Rectify the root cause before restarting filling operation.
5.6 Documentation Requirements
- Fill all records with blue ink. Do not leave blanks. Use ‘NA’ if not applicable.
- Ensure all entries are reviewed and signed by IPQA before continuation of filling.
- Attach the weight check data with the respective batch manufacturing records.
- Maintain trend data for weight checks for all products for ongoing process monitoring.
5.7 Training
- All personnel involved in IPC weight checks must be trained in the use of balances and GMP practices.
- Training must be documented in the Training Record Log (Annexure-4).
6. Abbreviations
- SOP: Standard Operating Procedure
- IPC: In-Process Control
- BMR: Batch Manufacturing Record
- QA: Quality Assurance
- IPQA: In-Process Quality Assurance
7. Documents
- Balance Calibration Log – Annexure-1
- Weight Verification Log – Annexure-2
- Deviation Report Form – Annexure-3
- Training Record Log – Annexure-4
8. References
- WHO GMP Guidelines for Sterile Products
- 21 CFR Part 211 – Current Good Manufacturing Practice
- ICH Q8(R2) – Pharmaceutical Development
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | Production Executive | QA Executive | Head QA |
| Department | Production | Quality Assurance | Quality Assurance |
11. Annexures
Annexure-1: Balance Calibration Log
| Balance ID | Location | Last Calibration | Next Due | Status |
|---|---|---|---|---|
| BLN-01 | Filling Room | 01/06/2025 | 01/12/2025 | Calibrated |
Annexure-2: Weight Verification Log
| Date | Batch No. | Time | Unit No. | Gross Weight (mg) | Net Weight (mg) | Result | Checked By |
|---|---|---|---|---|---|---|---|
| 24/06/2025 | INJ/0625/01 | 10:00 | 1 | 515 | 500 | Pass | Rajesh Kumar |
Annexure-3: Deviation Report Form
| Deviation ID | Date | Description | Immediate Action | Corrective/Preventive Action | Approved By |
|---|---|---|---|---|---|
| DEV/IPC/005 | 24/06/2025 | Weight below limit in 2 units | Line paused | Nozzle cleaned, line retrained | Sunita Reddy |
Annexure-4: Training Record Log
| Employee Name | Department | Training Date | Trainer | Remarks |
|---|---|---|---|---|
| Ajay Mehta | Production | 15/06/2025 | QA Executive | Completed |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/07/2022 | 1.0 | Initial version | New SOP | Head QA |
| 25/06/2025 | 2.0 | Updated procedure steps and annexures | Annual Review | Head QA |