Standard Operating Procedure for Visual Inspection of Tablet Coating Uniformity
| Department | Quality Control |
|---|---|
| SOP No. | SOP/TAB/103/2025 |
| Supersedes | SOP/TAB/103/2022 |
| 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 visually inspecting the uniformity of tablet coatings, ensuring that the coating process is consistent and meets product specifications for appearance and quality.
2. Scope
This SOP applies to the visual inspection of coated tablets during the manufacturing process. It covers the identification of coating defects, color uniformity, and any other coating-related issues.
3. Responsibilities
- Quality Control (QC): Responsible for performing the visual inspection of tablet coating uniformity and ensuring that all tablets meet the required quality standards for appearance.
- Quality Assurance (QA): Reviews the visual inspection results to ensure compliance with regulatory and product specifications.
- Coating Operators: Ensure proper coating procedures are followed during the tablet manufacturing process to achieve uniform coating application.
4. Accountability
The QC Manager is accountable for overseeing the visual inspection process and ensuring that the coated tablets meet the required standards. The QA Manager is responsible for approving the inspection results before the release of the product.
5. Procedure
5.1 Inspection Preparation
- Ensure that the tablet coating equipment has been calibrated and is functioning correctly before starting the inspection process.
- Prepare the inspection area by ensuring proper lighting, a clean environment, and any necessary tools, such as magnifying lenses or inspection trays.
- Collect a representative sample of coated tablets from the batch, ensuring that the sample size is adequate to evaluate coating uniformity (usually 10–20 tablets, or as specified in the batch record).
5.2 Visual Inspection Process
- Examine the tablets for overall coating appearance. Check for uniformity in coating color, thickness, and surface finish.
- Inspect each tablet for coating defects such as:
- Uneven coating
- Peeling or cracking
- Spotting or discoloration
- Air bubbles or blisters
- Chipping or other physical damage to the coating
- If defects are identified, record the findings and segregate the defective tablets for further evaluation and investigation.
5.3 Acceptance Criteria
- Coating should be uniform across the entire surface of the tablet, without visible defects such as cracks, chips, or peeling.
- Color consistency should be within acceptable limits, with no significant variations between individual tablets or within different areas of a tablet.
- Any defects or variations that fall outside of the established acceptable limits should be documented, and corrective actions should be implemented (Annexure-1).
5.4 Documentation and Record-Keeping
- Document the visual inspection results, including any defects observed, corrective actions taken, and the number of defective tablets found, in the batch record (Annexure-1).
- Ensure that all inspection records are signed, dated, and stored according to the company’s record retention policy for future audits and inspections.
- Maintain a log of any corrective actions taken during the inspection process, along with the outcome of rework or corrective measures.
5.5 Post-Inspection Actions
- Segregate defective tablets from the acceptable batch and follow the established procedure for investigating and resolving coating defects.
- If necessary, perform additional tests or rework the coating process to meet uniformity standards and re-inspect the tablets.
6. Abbreviations
- SOP: Standard Operating Procedure
- GMP: Good Manufacturing Practice
- QC: Quality Control
- QA: Quality Assurance
7. Documents
- Batch Record (Annexure-1)
- Defective Tablet Report (Annexure-2)
8. References
- USP <1216> – Tablet Coating and Inspection
- 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
- European Pharmacopoeia (EP) – Coating Specifications and Inspection 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: Batch Record
| Batch Number | Tablet Sample | Coating Uniformity | Defect Type | Corrective Action |
|---|---|---|---|---|
| Batch 001 | Tablet Sample | Uniform | None | Pass |
Annexure-2: Defective Tablet Report
| Defect Date | Batch Number | Defect Description | Corrective Action Taken | Responsible Person |
|---|---|---|---|---|
| 15/12/2025 | Batch 001 | Cracking in coating | Reworked coating 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 Inspection Process | Refined defect categorization | QA Head |