Standard Operating Procedure for Impurity Profiling of Sterile Products
| Department | Sterile Injectable Manufacturing |
|---|---|
| SOP No. | SOP/SIM/162/2025 |
| Supersedes | SOP/SIM/162/2022 |
| Page No. | Page 1 of 15 |
| Issue Date | 24/06/2025 |
| Effective Date | 26/06/2025 |
| Review Date | 24/06/2026 |
1. Purpose
This SOP outlines the standard procedures for profiling impurities in sterile injectable pharmaceutical products. It includes identification, quantification, classification, and reporting of impurities using validated analytical methods to ensure safety, efficacy, and compliance with pharmacopeial and ICH guidelines.
2. Scope
This SOP
is applicable to the Quality Control (QC) department involved in testing of all sterile injectable products manufactured at the facility. It covers routine analysis, stability studies, and investigational impurity profiling.
3. Responsibilities
- QC Analyst: Execute impurity profiling tests and ensure accurate documentation.
- QC Supervisor: Review test data and interpret results for regulatory compliance.
- QA Department: Approve reports, investigate OOS/OOT results, and ensure SOP adherence.
- Instrument Technician: Ensure instruments like HPLC and GC are calibrated and operational.
4. Accountability
The Head – Quality Control is accountable for the execution, review, and documentation of impurity profiling activities.
5. Procedure
5.1 Impurity Classification
- Organic Impurities – process-related or degradation products
- Inorganic Impurities – reagents, ligands, heavy metals
- Residual Solvents – as per ICH Q3C guidelines
5.2 Instrumentation and Equipment
- HPLC system with UV/ELSD/RI/PDA detectors
- Gas Chromatograph with FID/TCD
- Analytical Balance (0.1 mg accuracy)
- pH meter, Sonicator, Auto-sampler
- Validated software for data acquisition (e.g., Empower, Chromeleon)
5.3 Reference Standards
- Use pharmacopeial or certified in-house reference standards.
- Store under recommended conditions (Annexure-1: Reference Standard Log).
- Document usage and expiry verification in test worksheet.
5.4 Sample Preparation
- Withdraw required volume (as per method) of sample under aseptic conditions.
- Filter through 0.22 μm membrane if required.
- Prepare blanks, standards, and spiked recovery solutions.
5.5 Analytical Testing
5.5.1 Organic Impurity Profiling (HPLC)
- Set column temperature, flow rate, and mobile phase as per validated method.
- Inject blank, standard, sample, and recovery solution.
- Calculate % impurities and total impurities.
5.5.2 Residual Solvent Analysis (GC)
- Prepare standard and sample vials with internal standard.
- Inject into GC with appropriate column (e.g., DB-624).
- Quantify residual solvents per ICH Q3C limits.
5.5.3 Inorganic Impurity Analysis
- Use appropriate colorimetric method or ICP-MS if applicable.
- Record observations and confirm results against specification.
5.6 Acceptance Criteria
- Total impurities < NMT 2.0%
- Any unidentified impurity < NMT 0.2%
- Any individual known impurity < NMT 0.5%
- Residual solvents: Class I – NMT 2 ppm, Class II/III – as per ICH
5.7 OOS/OOT Handling
- Initiate deviation and investigation as per QA protocol.
- Reanalyze sample if required, under QA supervision.
- Document final disposition based on risk assessment.
5.8 Documentation
- Record all chromatograms, observations, and peak integrations in Annexure-2: Test Data Sheet.
- Compile a summary report (Annexure-3) with chromatographic data and interpretations.
6. Abbreviations
- SOP: Standard Operating Procedure
- QC: Quality Control
- QA: Quality Assurance
- HPLC: High Performance Liquid Chromatography
- GC: Gas Chromatography
- FID: Flame Ionization Detector
- OOS: Out of Specification
- OOT: Out of Trend
7. Documents
- Reference Standard Log – Annexure-1
- Test Data Sheet – Annexure-2
- Impurity Profiling Report – Annexure-3
8. References
- ICH Q3A/B – Impurities in New Drug Substances/Products
- ICH Q2(R1) – Validation of Analytical Procedures
- USP/NF General Chapters <621>, <467>
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | QC Analyst | QA Executive | Head QA |
| Department | Quality Control | Quality Assurance | Quality Assurance |
11. Annexures
Annexure-1: Reference Standard Log
| Standard Name | Lot No. | Expiry Date | Storage | Checked By |
|---|---|---|---|---|
| Impurity A | IMPA-011 | 15/08/2026 | 2–8°C | S. Sridhar |
Annexure-2: Test Data Sheet
| Sample ID | Impurity | RT (min) | Area % | Status |
|---|---|---|---|---|
| INJ1202 | Impurity B | 4.22 | 0.38 | Pass |
Annexure-3: Impurity Profiling Report
| Batch No. | Total Impurities (%) | Unidentified (%) | Decision | Reviewer |
|---|---|---|---|---|
| B240612 | 1.56 | 0.12 | Complies | Neha T. |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 01/01/2022 | 1.0 | Initial Release | New SOP | QA Head |
| 24/06/2025 | 2.0 | Included residual solvent and impurity reporting formats | Annual SOP Review | QA Head |