Standard Operating Procedure for Identification of Active Pharmaceutical Ingredient (API) by IR Spectroscopy
| Department | Elixir Department |
|---|---|
| SOP No. | SOP/ELX/213/2025 |
| Supersedes | SOP/ELX/213/2022 |
| Page No. | Page 1 of 9 |
| Issue Date | 11/04/2025 |
| Effective Date | 15/04/2025 |
| Review Date | 11/04/2026 |
1. Purpose
To establish a standardized procedure for the identification of Active Pharmaceutical Ingredients (APIs) in elixir formulations using Infrared (IR) Spectroscopy. This ensures reliable and accurate confirmation of API identity as per pharmacopeial standards.
2. Scope
This SOP applies to all quality control analysts performing identification of APIs by IR spectroscopy for raw materials, intermediate samples, and finished elixir products in the Elixir Department.
3. Responsibilities
- QC Analyst:
- Prepare samples and standard, operate the IR spectrophotometer, and document spectra.
- QC Supervisor:
- Verify the comparison of sample spectra with reference spectra and ensure data integrity.
- QA Officer:
- Review and approve results as part of batch release process.
4. Accountability
The QC Head is accountable for ensuring the IR method is validated and properly executed. QA is responsible for the final verification of identity test records.
5. Procedure
5.1 Instrument Preparation
- Ensure the IR spectrophotometer (FTIR or dispersive) is clean, calibrated, and switched on for at least 30 minutes before use.
- Verify background scan is performed and saved prior to analysis.
- Use desiccated potassium bromide (KBr) or ATR (Attenuated Total Reflectance) setup as per method.
5.2 Preparation of Reference Standard
- Dry the API reference standard if required (as per method).
- Grind with dry KBr in a 1:100 ratio and press into a transparent pellet using a pellet press (if KBr method is used).
- If using ATR, place the pure standard on the crystal and scan directly.
5.3 Preparation of Test Sample
- Take a portion of dried API or extract API from elixir matrix if required (as per method).
- Prepare KBr pellet or use ATR method, ensuring no contamination.
5.4 IR Spectral Scan
- Place sample or pellet in sample holder/ATR plate.
- Run the scan in the IR range of 4000 to 400 cm⁻¹.
- Record the spectra and overlay with the standard/reference spectra.
5.5 Interpretation and Acceptance Criteria
- Compare characteristic peaks (e.g., functional group region, fingerprint region).
- The sample must show matching peaks within ±2 cm⁻¹ of the standard spectrum.
- No additional or missing peaks should be observed in the sample spectrum.
5.6 Documentation
- Save and print the IR spectra of standard and sample.
- Record test details in the IR Identification Logbook (Annexure-1).
- Attach the spectra and result summary in the batch file or analytical worksheet.
5.7 Precautions
- Use clean and dry equipment for pellet preparation.
- Do not touch KBr pellets with bare hands.
- Ensure desiccator storage of KBr powder and pellets to prevent moisture interference.
6. Abbreviations
- API: Active Pharmaceutical Ingredient
- IR: Infrared
- SOP: Standard Operating Procedure
- QA: Quality Assurance
- QC: Quality Control
- KBr: Potassium Bromide
- ATR: Attenuated Total Reflectance
7. Documents
- IR Identification Logbook (Annexure-1)
- Instrument Calibration Certificate
- Batch Manufacturing Record (BMR)
8. References
- USP General Chapter <197K> – Identification by Infrared Spectroscopy
- 21 CFR Part 211.165 – Testing and Release for Distribution
- ICH Q2(R1) – Validation of Analytical Procedures
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: IR Identification Logbook
| Date | Batch No. | Sample ID | Method Used | Result | Tested By | Checked By |
|---|---|---|---|---|---|---|
| 11/04/2025 | ELX-0425-031 | API-A | USP IR Method | Complies | Rajesh Kumar | Sunita Reddy |
Revision History:
| Revision Date | Revision No. | Revision Details | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial Release | New SOP | QA Head |
| 11/04/2025 | 2.0 | Added ATR method and precautions for sample prep | Method Update | QA Head |