and approving the test results.

5. Procedure

5.1 Preparation for Robustness Testing

1. Select the analytical method to be tested for robustness (e.g., HPLC, UV-Vis, GC).
2. Review the method’s existing validation data to identify critical parameters that may affect the method’s performance (e.g., column type, mobile phase, flow rate, temperature, detector settings).
3. Prepare a test plan detailing the specific conditions under which the robustness tests will be conducted. These conditions should include variations in the critical parameters identified.
4. Obtain appropriate reference standards and tablet samples to conduct the robustness testing.

5.2 Defining the Critical Parameters

1. Identify critical parameters that could affect the method’s performance. Common parameters include:
   • HPLC: Mobile phase composition, flow rate, temperature, column type
   • UV-Vis: Wavelength, solvent composition, path length
   • GC: Injection temperature, carrier gas flow rate, column type
2. Determine the acceptable range of variation for each critical parameter based on method validation data and historical performance.

5.3 Conducting the Robustness Testing

1. Perform the analytical tests by varying one critical parameter at a time while keeping others constant. For example:
   • For HPLC: Vary the flow rate (e.g., ±10%), column temperature (e.g., ±5°C), and mobile phase composition (e.g., ±5% of acetonitrile).
   • For UV-Vis: Test the effect of changing the wavelength (e.g., ±2 nm) and solvent composition (e.g., ±5% ethanol).
   • For GC: Vary the injection temperature (e.g., ±10°C), carrier gas flow rate (e.g., ±5%), and column type.
2. For each variation, prepare and analyze a minimum of three replicates to assess the consistency and reliability of the method.
3. Record all test conditions, including the specific variation applied to the critical parameter, and document the results for each replicate.

5.4 Data Analysis and Interpretation

1. Analyze the results from the robustness tests by comparing the test outcomes under different conditions. Look for significant deviations in the results due to parameter variations.
2. Calculate the percent deviation in the analytical results (e.g., retention time, peak area, or absorbance) for each parameter variation.
3. Determine if the method remains within acceptable limits for each variation. An acceptable limit is typically a ±5% variation, unless otherwise specified by regulatory standards.
4. If the method shows significant variation (greater than acceptable limits), investigate the cause and perform further optimization or validation of the method.

5.5 Acceptance Criteria

1. The analytical method is considered robust if the results remain consistent and within acceptable limits (±5% deviation) despite small changes in critical parameters.
2. If the method is found to be sensitive to variations, corrective actions should be implemented, which may include method modification or revalidation.
3. Any deviations from expected results should be documented in the deviation report (Annexure-1), and further investigations should be initiated as required.

5.6 Documentation and Record-Keeping

1. Document all robustness testing results, including the variations applied, test conditions, and the results of each test in the batch record (Annexure-2).
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 raw data, including chromatograms, spectra, and test reports, for regulatory compliance and future reference.

5.7 Post-Test Actions

1. Clean the laboratory instruments and equipment after each use according to the instrument’s SOP to avoid cross-contamination.
2. Dispose of any used samples, reagents, or solvents according to the company’s waste disposal procedures.
3. Ensure that the analytical instruments are regularly calibrated and maintained according to the manufacturer’s instructions and company SOPs.

6. Abbreviations

• SOP: Standard Operating Procedure
• GMP: Good Manufacturing Practice
• QC: Quality Control
• QA: Quality Assurance
• HPLC: High-Performance Liquid Chromatography
• UV-Vis: Ultraviolet-Visible Spectroscopy
• GC: Gas Chromatography

7. Documents

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

8. References

• USP <621> – Chromatography
• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
• European Pharmacopoeia (EP) – Chromatography and Method Validation Specifications

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Deviation Report

Deviation Date	Batch Number	Deviation Description	Corrective Action	Responsible Person
15/12/2025	Batch 001	Deviations found in method robustness	Recalibrated method and optimized conditions	Jane Doe

Annexure-2: Batch Record

Batch Number	Critical Parameter Tested	Variation Applied	Result
Batch 001	Flow Rate (HPLC)	±5%	Pass

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 Protocol	Improved robustness criteria	QA Head