activities align with ICH Q2(R1), WHO guidelines, and GMP expectations.

2. Scope

This SOP applies to all validated analytical methods developed by the Analytical Method Development (AMD) department that are subject to change in formulation, manufacturing site, equipment, or process, and require partial or full revalidation.

3. Responsibilities

• Analyst: Performs the revalidation experiments and maintains raw data.
• Group Leader: Evaluates need for revalidation and prepares the revalidation protocol.
• QA Executive: Reviews and approves the revalidation protocol and final report.
• Department Head: Ensures that revalidation is completed and implemented appropriately.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring revalidation of analytical methods in accordance with regulatory requirements and internal quality systems.

5. Procedure

5.1 Triggers for Revalidation

1. Change in API or formulation composition.
2. Transfer of method to a new laboratory or manufacturing site.
3. Change in critical equipment (e.g., new HPLC model, different column manufacturer).
4. Change in sample matrix or concentration range.
5. Failure to meet system suitability or method performance criteria.
6. Periodic review as part of a regulatory requirement or product lifecycle management.

5.2 Types of Revalidation

1. Full Revalidation: Required when the method is used for a new product, new equipment, or significantly altered matrix.
2. Partial Revalidation: Performed when only specific parameters are affected, e.g., linearity range or detection limit.

5.3 Revalidation Protocol Preparation

1. Prepare a detailed protocol including:
   • Objective
   • Scope and type of revalidation
   • Parameters to be tested: accuracy, precision, specificity, linearity, robustness, LOD, LOQ, etc.
   • Acceptance criteria
   • Test materials and batch details
   • Responsibility matrix and timeline
2. Get protocol reviewed by QA and approved before execution.

5.4 Execution of Revalidation

1. Conduct experiments as per protocol.
2. Ensure compliance with ICH Q2(R1) during:
   • Accuracy (recovery studies)
   • Precision (repeatability and intermediate precision)
   • Linearity (minimum 5 points)
   • LOD and LOQ determination
   • Specificity and robustness evaluation
3. Document all data in Annexure-1 and chromatograms in Annexure-2.

5.5 Compilation of Report

1. Summarize findings in Annexure-3: Revalidation Summary Report.
2. Compare results with original validation to assess equivalency or improvement.
3. QA to review and approve report before release of revalidated method.

5.6 Change Control and Communication

1. Initiate a change control document post-approval of revalidation.
2. Update internal method database and notify relevant departments.

6. Abbreviations

• SOP: Standard Operating Procedure
• QA: Quality Assurance
• LOD: Limit of Detection
• LOQ: Limit of Quantification
• AMD: Analytical Method Development
• ICH: International Council for Harmonisation

7. Documents

1. Revalidation Data Sheet – Annexure-1
2. Chromatogram Archive – Annexure-2
3. Revalidation Summary Report – Annexure-3

8. References

• ICH Q2(R1): Validation of Analytical Procedures
• GMP Guidelines – Schedule M
• WHO TRS 996

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Rahul Menon	Geeta Thakur	Sunita Reddy
Designation	Sr. Analyst	QA Reviewer	Head – AMD
Department	Analytical Method Development	QA	Analytical Method Development

11. Annexures

Annexure-1: Revalidation Data Sheet

Test	Result	Acceptance Criteria	Status
Precision	0.85% RSD	≤ 2.0%	Pass
Accuracy	98.8%–101.2%	95–105%	Pass
Linearity	r² = 0.998	≥ 0.990	Pass

Annexure-2: Chromatogram Archive

All relevant chromatograms are filed in QA logbook ref: QA/AMD/CHROM/207/2025

Annexure-3: Revalidation Summary Report

Method Title	Assay of Loratadine
Revalidation Type	Partial
Reason	Instrument change from Waters 2489 to Agilent 1260
Conclusion	Method meets validation criteria and is suitable for continued use

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
21/05/2025	2.0	Expanded to include change control linkage	Annual Review	Sunita Reddy
05/02/2022	1.0	Initial Release	New SOP	QA Head