Standard Operating Procedure for Weight Uniformity During Coating Process

Department	Tablet
SOP No.	SOP/TAB/138/2025
Supersedes	SOP/TAB/138/2022
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 ensuring weight uniformity during the coating process of tablets, ensuring that the weight of each tablet is consistent and meets the required specifications for product quality.

2. Scope

This SOP applies to the monitoring and control of tablet weight during the coating process, ensuring that each tablet meets the defined weight specifications.

3. Responsibilities

• Quality Control (QC): Responsible for conducting weight uniformity tests on coated tablets at regular intervals during the coating process and ensuring compliance with weight specifications.
• Tablet Coating Operator: Responsible for applying the coating consistently and following the SOP for maintaining uniform tablet weight during the process.
• Quality Assurance (QA): Ensures that the coating process adheres to the SOP, reviews the results, and verifies compliance with weight uniformity specifications.

4. Accountability

The QC Manager is accountable for ensuring that weight uniformity is monitored and controlled during the tablet coating process. The QA Manager is responsible for reviewing the results and ensuring that the batch complies with the required weight specifications.

5. Procedure

5.1 Sample Collection

1. During the coating process, collect a representative sample of coated tablets from different stages of the batch (e.g., early, middle, and late stages of the coating process) to ensure consistency across the entire batch.
2. Ensure that the sample size meets the required quantity, typically 10 tablets per batch for weight uniformity testing.
3. Weigh each tablet in the sample individually and record the weight data.

5.2 Weight Uniformity Testing

1. Calculate the average weight of the sample tablets.
2. Calculate the percentage deviation from the average weight for each individual tablet.
3. Compare the deviation results with the acceptable weight variation limits, typically ± 5% for tablets with a specified weight of more than 250 mg.
4. If any tablet exceeds the allowed deviation, the batch may need to be adjusted, and the affected tablets should be reprocessed.

5.3 Monitoring During Coating Process

1. During the coating process, monitor the application of the coating material to ensure uniformity in coverage.
2. Ensure that the coating is applied evenly, without over-spray or under-spray, which can affect the final tablet weight.
3. Adjust the coating parameters, such as the spray rate, atomization pressure, and coating pan speed, as necessary to maintain consistent tablet weight.

5.4 Corrective Actions

1. If the weight uniformity is outside the acceptable range, stop the coating process and investigate the cause of the variation.
2. Possible corrective actions may include adjusting the coating solution concentration, changing the application parameters (e.g., spray rate or pan speed), or increasing or decreasing the coating time.
3. Once adjustments are made, re-test the sample tablets for weight uniformity to verify that the issue has been resolved.

5.5 Documentation

1. Document the results of the weight uniformity tests, including individual tablet weights, average weight, deviation percentage, and any corrective actions taken in the batch record (Annexure-2).
2. Document any deviations from the standard weight uniformity range and the corrective actions taken in the deviation report (Annexure-1).
3. Ensure that all records are signed, dated, and reviewed by QA for compliance with quality standards.

5.6 Acceptance Criteria

1. The weight variation of each tablet should not exceed ± 5% of the average tablet weight for tablets weighing more than 250 mg.
2. If the weight variation exceeds the acceptable limit, the batch may need to be rejected or reworked.

5.7 Post-Coating Actions

1. Once the tablets pass the weight uniformity test, proceed with the next steps in tablet processing, such as drying, packaging, and labeling.
2. Ensure that the coating equipment is cleaned and calibrated according to the preventive maintenance schedule after each use.

6. Abbreviations

• SOP: Standard Operating Procedure
• GMP: Good Manufacturing Practice
• QC: Quality Control
• QA: Quality Assurance
• API: Active Pharmaceutical Ingredient

7. Documents

1. Batch Record (Annexure-2)
2. Deviation Report (Annexure-1)

8. References

• USP <905> – Uniformity of Dosage Units
• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
• European Pharmacopoeia (EP) – Weight Uniformity 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: Deviation Report

Deviation Date	Batch Number	Deviation Description	Corrective Action	Responsible Person
15/12/2025	Batch 001	Tablet weight variation exceeded 5%	Adjusted coating process parameters	John Doe

Annexure-2: Batch Record

Sample Number	Tablet Weight	Deviation	Action Taken
Sample 1	500 mg	Pass (Deviation: 2%)	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 coating process and testing method	Improved weight monitoring	QA Head