Standard Operating Procedure for Precision Study via Repeatability Testing in Analytical Method Development
| Department | Analytical Method Development |
|---|---|
| SOP No. | SOP/AMD/368/2025 |
| Supersedes | SOP/AMD/368/2022 |
| Page No. | Page 1 of 12 |
| Issue Date | 01/06/2025 |
| Effective Date | 03/06/2025 |
| Review Date | 01/06/2027 |
1. Purpose
This SOP outlines the detailed procedure for performing precision studies using repeatability testing as part of analytical method validation. Precision is defined as the closeness of agreement among individual test results when the
2. Scope
This procedure applies to all quantitative analytical methods developed or validated for drug substances, drug products, raw materials, and excipients by the Analytical Method Development (AMD) department.
3. Responsibilities
- Analyst: Conducts repeatability tests as per the validated method and documents all observations.
- AMD Scientist: Reviews chromatograms/data sheets and calculates statistical metrics.
- QA Reviewer: Verifies calculations and ensures protocol compliance before final report approval.
4. Accountability
The Head of Analytical Method Development is responsible for ensuring proper execution, review, documentation, and archiving of all precision study reports in accordance with regulatory standards such as ICH Q2(R1), WHO TRS, and 21 CFR Part 211.
5. Procedure
5.1 Preparation for Repeatability Testing
- Select a single batch or standard preparation to represent a homogeneous sample.
- Prepare six independent sample preparations of the same concentration under identical conditions.
- Use the validated method parameters including mobile phase, flow rate, detection wavelength, etc.
5.2 Instrument Setup and Sample Analysis
- Calibrate the instrument before initiating the run using calibration standards.
- Inject each of the six preparations in sequence under the same operating conditions.
- Record peak areas or detector responses for each preparation.
5.3 Calculation of Results
- Calculate the assay or measured concentration for each sample preparation.
- Determine the mean, standard deviation (SD), and relative standard deviation (%RSD).
- Acceptance criteria: %RSD should typically be ≤2.0% for assay methods, unless otherwise justified by method sensitivity.
5.4 Documentation and Reporting
- Document all chromatograms, system suitability data, sample preparation details, and calculation sheets.
- Summarize the results using Annexure-1: Precision Summary Sheet.
- Prepare a report for submission to QA, including graphical representations (box plots, if applicable) of repeatability data.
6. Abbreviations
- RSD: Relative Standard Deviation
- SD: Standard Deviation
- QA: Quality Assurance
- AMD: Analytical Method Development
7. Documents
- Annexure-1: Precision Summary Sheet
- Analytical Method Validation Protocol
- Instrument Calibration Records
8. References
- ICH Q2(R1): Validation of Analytical Procedures
- USP General Chapter <1225>: Validation of Compendial Procedures
- 21 CFR Part 211 – Current Good Manufacturing Practices
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | Ramesh Pawar | Sunita Joshi | Dr. Neeraj Deshmukh |
| Designation | Method Development Analyst | QA Officer | Head – Analytical Method Development |
| Department | Analytical Method Development | Quality Assurance | Analytical Method Development |
11. Annexures
Annexure-1: Precision Summary Sheet
| Sample No. | Result (%) |
|---|---|
| 1 | 99.8% |
| 2 | 100.2% |
| 3 | 99.9% |
| 4 | 100.1% |
| 5 | 99.7% |
| 6 | 100.0% |
Mean: 99.95% | SD: 0.19 | %RSD: 0.19%
Conclusion: The method meets the precision criteria with excellent repeatability.
Revision History
| Revision Date | Revision No. | Description | Reason | Approved By |
|---|---|---|---|---|
| 01/06/2025 | 2.0 | Added annexures and updated acceptance limits | Annual SOP Review | Dr. Neeraj Deshmukh |
| 10/07/2022 | 1.0 | Initial Release | New SOP | QA Head |