Standard Operating Procedure for In-Process Control during Film Coating Process

Department	Tablet
SOP No.	SOP/TAB/042/2025
Supersedes	SOP/TAB/042/2022
Page No.	Page 1 of 6
Issue Date	06/09/2025
Effective Date	11/09/2025
Review Date	06/09/2026

1. Purpose

The purpose of this SOP is to establish guidelines for in-process control during the film coating process of tablets. In-process control ensures that the coating is applied uniformly, meets quality specifications, and prevents defects such as uneven coating, cracking, or poor adhesion.

2. Scope

This SOP applies to all tablet formulations requiring film coating. It covers the process of monitoring and controlling critical parameters, such as temperature, humidity, spray rate, and coating uniformity during the film coating process.

3. Responsibilities

• Manufacturing Personnel: Responsible for performing the film coating process and monitoring in-process parameters to ensure compliance with this SOP.
• Quality Control (QC): Responsible for conducting in-process checks, recording data, and ensuring that the coating process stays within the acceptable limits.
• Quality Assurance (QA): Ensures that in-process controls are consistently followed and that any deviations are investigated and documented. Reviews final batch records and inspection results.

4. Accountability

The Production Manager is accountable for overseeing the film coating process and ensuring that all in-process controls are performed correctly. The QA Manager is responsible for ensuring that all in-process control parameters are adhered to and that deviations are addressed.

5. Procedure

5.1 Pre-Coating Setup

1. Ensure that all necessary equipment, including the coating pan, spray guns, and control systems, are calibrated and in good working order.
2. Verify that the film coating solution is prepared according to the formulation sheet and is free from any undissolved particles or foreign matter.
3. Check the temperature and humidity levels in the coating room to ensure they are within the specified limits for optimal coating conditions.
4. Ensure that the coating pan is clean and properly set up for tablet processing.

5.2 In-Process Control during Coating Application

1. Start the coating process by spraying the coating solution onto the tablets. Continuously monitor the spray rate and adjust as necessary to ensure uniform coverage of the tablets.
2. Check the temperature and humidity inside the coating pan regularly. The temperature should typically be between 40°C to 50°C to prevent over-drying or under-drying the coating.
3. Ensure that the airflow is within the required range to facilitate proper drying of the coating and prevent the accumulation of moisture.
4. Monitor the tablets for any signs of over-saturation or under-coating. Adjust the spray rate, airflow, and rotation speed to achieve uniform tablet coating.
5. Measure the thickness of the coating during the process using appropriate tools, ensuring that it remains within the predefined specifications.

5.3 In-Process Monitoring

1. Perform regular checks to ensure uniformity of the coating. Look for signs of uneven coating, streaking, or tablet clustering.
2. Monitor the pressure and temperature of the spray system, ensuring that the settings are consistent with the recommended values.
3. Perform regular checks of the coating solution’s viscosity. If the viscosity changes, adjust the formulation or process settings accordingly.
4. Check for any defects in the coating, such as peeling, cracking, or blistering, and adjust the process parameters to prevent these defects.
5. Ensure that the tablets are evenly distributed in the coating pan, preventing over-saturation and achieving a smooth coating finish.

5.4 Post-Coating Inspection

1. Once the coating process is complete, conduct a final inspection of the tablets for uniformity, coating defects, and overall quality.
2. Measure the final coating thickness to ensure it meets the predefined specifications. If the coating is too thick or too thin, adjust the process for future batches.
3. Perform hardness and friability tests on a sample of tablets to confirm that the coating does not compromise tablet strength or durability.
4. Document all inspection results in the batch record (Annexure-1) and record any deviations from the process in the deviation report (Annexure-2).

5.5 Documentation and Record-Keeping

1. Record all in-process checks, including spray rate, temperature, humidity, coating thickness, and any deviations, in the batch record (Annexure-1).
2. Ensure that any deviations or corrective actions taken are documented in the deviation report (Annexure-2).
3. Maintain records of all quality control tests, including coating thickness, friability, and hardness test results, for review during the final product release process.
4. Store all batch records, in-process checks, and inspection reports in a secure and organized manner for future audits and regulatory inspections.

5.6 Equipment Cleaning and Maintenance

1. After each batch, clean the coating equipment, including spray guns, hoses, and the coating pan, to remove any residual coating solution or powder.
2. Perform regular maintenance checks on all coating equipment to ensure that it is functioning properly. Document any maintenance activities in the maintenance log (Annexure-3).
3. Ensure that all parts of the equipment are thoroughly cleaned and sanitized to prevent contamination in subsequent batches.

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-1)
2. Deviation Report (Annexure-2)
3. Maintenance Log (Annexure-3)

8. References

• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
• EU GMP Guidelines Part I – Basic Requirements for Medicinal Products
• ICH Q7 – Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients

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 Type	Coating Solution	Coating Parameters	Coating Quality
Batch 001	Tablet A	Film coat solution: 5% HPMC	Temperature: 45°C, Airflow: 2.5 m³/min	Pass
Batch 002	Tablet B	Film coat solution: 7% PVA	Temperature: 50°C, Airflow: 3.0 m³/min	Pass

Annexure-2: Deviation Report

Deviation Date	Batch Number	Deviation Description	Corrective Action	Responsible Person
10/08/2025	Batch 003	Uneven coating observed during final inspection	Adjusted spray rate and reprocessed tablets	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 Coating Parameters and Inspection	Improved Process Efficiency	QA Head