Standard Operating Procedure for API Retention Time Validation for Tablets
| Department | Quality Control |
|---|---|
| SOP No. | SOP/TAB/115/2025 |
| Supersedes | SOP/TAB/115/2022 |
| Page No. | Page 1 of 7 |
| Issue Date | 01/03/2026 |
| Effective Date | 06/03/2026 |
| Review Date | 01/03/2027 |
1. Purpose
To define the procedure for validating the retention time of the active pharmaceutical ingredient (API) in tablet formulations using High-Performance Liquid Chromatography (HPLC), ensuring consistency and accuracy in API identification and quantification.
2. Scope
This SOP applies to the validation of retention times for the API in tablet formulations using HPLC. The method ensures that the retention time of the API is consistent with established specifications and provides reliable data for quality control and regulatory compliance.
3. Responsibilities
- Quality Control (QC): Responsible for performing retention time validation and ensuring that the results comply with specifications.
- Quality Assurance (QA): Ensures that the retention time validation is performed according to the SOP and reviews the results for compliance with regulatory standards.
- Laboratory Personnel: Responsible for preparing samples, operating the HPLC system, and recording results accurately.
4. Accountability
The QC Manager is accountable for ensuring the accurate performance of retention time validation. The QA Manager is responsible for reviewing and approving the results to ensure consistency and reliability in API testing.
5. Procedure
5.1 Sample Preparation
- Weigh an appropriate amount of tablet sample (usually 10 tablets) to obtain a representative quantity for testing.
- Crush the tablets to a fine powder using a mortar and pestle or mechanical grinder to ensure uniformity.
- Dissolve the powder in an appropriate solvent (e.g., methanol or acetonitrile) based on the solubility of the API, and filter the solution using a 0.45 µm filter.
- If necessary, dilute the solution to bring the concentration within the optimal range for HPLC analysis.
5.2 HPLC System Setup
- Ensure that the HPLC system is properly calibrated and the appropriate column is installed for API separation.
- Set up the mobile phase, flow rate, and other conditions (e.g., temperature, detection wavelength) based on the method validation specifications.
- Prime the system to ensure consistent flow and eliminate air bubbles in the pump or lines.
5.3 Retention Time Validation
- Inject a known standard of the API into the HPLC system to establish a baseline retention time under the selected conditions.
- Inject the prepared tablet sample and record the retention time for the API peak in the chromatogram.
- Compare the retention time of the tablet sample with that of the standard. The retention time should match within an acceptable range (typically ±5% of the standard’s retention time).
- Perform the test in triplicate to ensure reproducibility of the results.
5.4 Data Analysis and Calculation
- Calculate the average retention time for the API from the triplicate injections.
- Ensure that the average retention time falls within the specified range of the standard’s retention time. Any significant deviations must be investigated.
- Document all observations and results, including chromatograms, retention time data, and any deviations from the expected results.
5.5 Acceptance Criteria
- The retention time of the API should be consistent with the standard within the allowable limits (±5%).
- If the retention time falls outside the acceptable range, initiate an investigation to identify potential issues, such as incorrect mobile phase composition, column problems, or sample contamination.
- Corrective actions should be taken as necessary, and re-testing should be performed once the issue is resolved.
5.6 Documentation and Record-Keeping
- Record all validation results, including chromatograms, retention time calculations, and observations in the batch record (Annexure-2).
- Ensure that all records are signed, dated, and stored according to the company’s record retention policy for future audits and inspections.
- Maintain raw data, including instrument logs, standard preparation details, and deviation reports, for regulatory compliance and future reference.
5.7 Post-Test Actions
- Clean the HPLC system and associated equipment to remove any residual sample and prevent cross-contamination between tests.
- Dispose of used samples, solvents, and reagents according to the company’s waste disposal procedures.
- Ensure that the HPLC system is calibrated and maintained according to the manufacturer’s guidelines and company SOPs.
6. Abbreviations
- SOP: Standard Operating Procedure
- GMP: Good Manufacturing Practice
- QC: Quality Control
- QA: Quality Assurance
- API: Active Pharmaceutical Ingredient
- HPLC: High-Performance Liquid Chromatography
7. Documents
- Batch Record (Annexure-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) – Specifications for Chromatography and Method Validation
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 | Retention time variation beyond acceptable limit | Re-calibrated HPLC system and re-tested | Jane Smith |
Annexure-2: Batch Record
| Batch Number | Sample Weight (g) | API Retention Time (min) | Result |
|---|---|---|---|
| Batch 001 | 100 g | 8.5 min | 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 retention time limits | Improved precision and accuracy | QA Head |