Standard Operating Procedure for Coating Adhesion Testing for Film-Coated Tablets

Department	Tablet
SOP No.	SOP/TAB/094/2025
Supersedes	SOP/TAB/094/2022
Page No.	Page 1 of 7
Issue Date	01/03/2026
Effective Date	06/03/2026
Review Date	01/03/2027

1. Purpose

To outline the procedure for testing the adhesion of the film coating to tablets, ensuring that the coating adheres properly to the tablet surface without detaching or compromising the product quality during handling and storage.

2. Scope

This SOP applies to the testing of the coating adhesion for film-coated tablets to ensure the integrity and uniformity of the coating layer as per regulatory and product specifications.

3. Responsibilities

• Manufacturing Personnel: Responsible for preparing film-coated tablets for adhesion testing and ensuring that the coating process adheres to the established SOP.
• Quality Control (QC): Responsible for conducting the adhesion testing, recording results, and ensuring that the coating meets the required specifications.
• Quality Assurance (QA): Ensures that the adhesion testing procedure is followed correctly and reviews the results to approve or reject the batch for release.

4. Accountability

The QC Manager is accountable for ensuring the coating adhesion testing is conducted in compliance with this SOP. The QA Manager is responsible for reviewing the results and approving the batch for release.

5. Procedure

5.1 Sample Collection

1. Collect a representative sample of film-coated tablets from the batch, as specified in the batch record.
2. The sample should consist of a minimum of 10 tablets or as specified in the batch record or pharmacopeial guidelines.
3. Ensure that the tablets are free from defects such as cracks, chips, or coating defects.
4. Label the sample appropriately for identification during testing.

5.2 Preparation of Testing Apparatus

1. Ensure that all testing equipment (e.g., adhesion tester, test equipment, weighing balance) is clean, calibrated, and ready for use.
2. Set up the adhesion tester according to the manufacturer’s instructions, ensuring the proper application of force and measurement units.
3. Ensure that the test environment (e.g., temperature, humidity) is controlled as per the batch record or pharmacopeial requirements.

5.3 Performing Adhesion Test

1. Place the tablets on the adhesion tester one by one, ensuring they are positioned according to the test apparatus specifications.
2. Apply the specified force to the tablet surface as per the test method described in the batch record or pharmacopeial guidelines.
3. Measure the force required to detach the coating from the tablet surface, ensuring that the test is conducted on both the tablet surface and the edges.
4. Record the adhesion strength values for each tablet tested (Annexure-1).

5.4 Data Recording and Calculation

1. Record the adhesion strength values and any other observations (e.g., cracks, partial detachment) in the batch record (Annexure-1).
2. Calculate the average adhesion strength across all samples and compare it with the specified acceptance criteria.
3. Ensure that the coating adhesion meets the required specifications, typically a minimum adhesion strength to prevent coating detachment under normal handling conditions.

5.5 Acceptance Criteria

1. Ensure that the average adhesion strength meets the acceptance criteria specified in the batch record or pharmacopeial guidelines.
2. If the adhesion strength does not meet the criteria, investigate and document the findings in the deviation report (Annexure-2).
3. Take corrective actions as necessary and perform re-testing if required.

5.6 Documentation and Record-Keeping

1. Document all test results, including adhesion strength values, observations, and any deviations from the acceptance criteria in the batch record (Annexure-1).
2. Ensure that all records are signed, dated, and stored according to the company’s record retention policy for future audits and inspections.
3. Maintain all raw data, test results, and photographs (if applicable) for future reference and audits.

5.7 Post-Test Cleanup

1. Clean all equipment used for adhesion testing, including the adhesion tester and sample containers, according to the cleaning SOP to prevent contamination between tests.
2. Ensure that the testing equipment is properly maintained and calibrated for future use.

6. Abbreviations

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

7. Documents

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

8. References

• USP <601> – Film-Coated Tablets
• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
• European Pharmacopoeia (EP) – Coating Adhesion Testing

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Batch Record

Batch Number	Tablet Sample	Adhesion Strength (N)	Result
Batch 001	Film-Coated Tablet	1.2	Pass

Annexure-2: Deviation Report

Deviation Date	Batch Number	Deviation Description	Corrective Action	Responsible Person
15/12/2025	Batch 001	Low coating adhesion strength	Adjusted coating solution and reworked process	John Doe

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 Testing Procedures	Refined adhesion testing protocols	QA Head