Standard Operating Procedure for Investigating Tablet Coating Defects

Department	Tablet
SOP No.	SOP/TAB/211/2025
Supersedes	SOP/TAB/211/2022
Page No.	Page 1 of 6
Issue Date	01/03/2026
Effective Date	06/03/2026
Review Date	01/03/2027

1. Purpose

This SOP defines the process for investigating coating defects in tablet production. The objective is to identify the root cause of coating defects, ensure the corrective actions are implemented, and maintain tablet quality in compliance with GMP standards.

2. Scope

This SOP applies to the investigation of all coating defects observed during the tablet coating process, including defects such as uneven coating, chipping, cracking, or other visible defects in the finished product.

3. Responsibilities

• Quality Assurance (QA) Manager: Responsible for overseeing the investigation of coating defects and ensuring that corrective actions are implemented in compliance with regulatory standards.
• Production Team: Responsible for notifying QA of any coating defects, participating in the investigation, and implementing corrective measures as required.
• Coating Team: Responsible for identifying potential causes of defects during the coating process and assisting in the investigation.
• Regulatory Affairs Team: Ensures that the investigation process meets FDA and GMP compliance standards.

4. Accountability

The QA Manager is accountable for the investigation of coating defects and ensuring that corrective actions are taken. The Production and Coating Teams are responsible for identifying issues and supporting the investigation process.

5. Procedure

5.1 Identification of Coating Defects

1. Inspect the coated tablets visually for defects such as uneven coating, discoloration, chips, cracks, or poor adhesion.
2. Document the type and frequency of defects and identify the batch numbers and production dates associated with the defects (Annexure-1).
3. Notify the QA team immediately upon identifying any coating defects.

5.2 Investigation of Defects

1. The QA team will initiate an investigation into the identified coating defects.
2. Examine the coating process for possible causes of defects, including:
   • Improper coating equipment settings (e.g., spray rate, air flow, pan speed).
   • Incorrect coating material formulation (e.g., incorrect binder or solvent concentration).
   • Environmental conditions (e.g., humidity, temperature) during coating.
   • Possible contamination of raw materials used in the coating process.
3. Review the process parameters during the coating run, including equipment calibration, operator logs, and environmental conditions (Annexure-2).

5.3 Root Cause Analysis

1. Once the potential causes are identified, perform a root cause analysis to determine the exact cause of the defects (Annexure-3).
2. Involve the Coating Team, Production Team, and Quality Control to help identify any procedural, equipment, or material-related causes.
3. If necessary, use tools such as fishbone diagrams or failure mode analysis to guide the investigation.

5.4 Corrective Actions

1. Once the root cause has been identified, implement corrective actions to address the issue and prevent recurrence.
2. Corrective actions may include:
   • Adjusting equipment settings.
   • Modifying coating formulations.
   • Improving environmental control during the coating process.
   • Re-training operators on proper coating procedures.
3. Ensure that all corrective actions are documented and signed off by the QA Manager (Annexure-4).

5.5 Re-Testing and Validation

1. After corrective actions have been implemented, perform re-testing of the coating process using new batches to ensure that the defects have been resolved.
2. Validate the new coating process to ensure it meets product specifications (Annexure-5).
3. Document the results of the re-testing and validation, ensuring that all findings are recorded and signed off by the QA team.

5.6 Documentation and Record Keeping

1. Maintain detailed records of the defect investigation, including all steps taken, findings, corrective actions, and validation results (Annexure-6).
2. Store all records securely for future reference and regulatory inspection purposes.

6. Abbreviations

• SOP: Standard Operating Procedure
• QA: Quality Assurance
• QC: Quality Control
• GMP: Good Manufacturing Practice

7. Documents

1. Coating Defect Log (Annexure-1)
2. Coating Process Parameters Review (Annexure-2)
3. Root Cause Analysis Report (Annexure-3)
4. Corrective Action Plan (Annexure-4)
5. Coating Process Validation Report (Annexure-5)
6. Coating Defect Investigation Report (Annexure-6)

8. References

• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
• USP <1161> – Tablet Coating
• ISO 9001 – Quality Management Systems

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Coating Defect Log

Batch Number	Defect Type	Frequency	Reported By
Batch-12345	Uneven Coating	5 units	John Doe

Annexure-2: Coating Process Parameters Review

Parameter	Value	Acceptable Range	Action Taken
Spray Rate	100 mL/min	80-120 mL/min	Adjusted to 110 mL/min

Annexure-3: Root Cause Analysis Report

Root Cause	Impact	Corrective Action
Incorrect Spray Nozzle Setting	Uneven coating on tablets	Adjusted nozzle settings to optimal range

Annexure-4: Corrective Action Plan

Action ID	Action Description	Responsible Person	Completion Date
CAP-001	Recalibrate spray nozzle	John Doe	05/03/2026

Annexure-5: Coating Process Validation Report

Batch Number	Validation Status	Test Results
Batch-12345	Passed	Coating uniformity within specifications

Annexure-6: Coating Defect Investigation Report

Defect Type	Investigation Outcome	Corrective Actions
Chipping	Incorrect tablet compression force	Adjusted compression settings

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 investigation process	Clarified actions for coating defects	QA Head