Standard Operating Procedure for Selection of Analytical Techniques in Method Development
| Department | Analytical Method Development |
|---|---|
| SOP No. | SOP/AMD/363/2025 |
| Supersedes | SOP/AMD/363/2022 |
| Page No. | Page 1 of 14 |
| Issue Date | 01/06/2025 |
| Effective Date | 05/06/2025 |
| Review Date | 01/06/2027 |
1. Purpose
To define a systematic approach for selecting suitable analytical techniques for quantitative and qualitative method development of drug substances and products. The selection ensures compliance with regulatory standards and suitability for
intended application.
2. Scope
This SOP is applicable to all new or modified methods developed in the Analytical Method Development (AMD) department of pharmaceutical API and formulation units. It includes selection from techniques such as UV, HPLC, GC, FTIR, potentiometry, and titrimetry.
3. Responsibilities
- Analytical Chemist: Conducts literature review, selects technique, and documents justification.
- Method Development Scientist: Approves the selection based on preformulation data and validation feasibility.
- QA Officer: Reviews the selection rationale and supporting documentation for regulatory compliance.
4. Accountability
The Head of AMD Department is accountable for ensuring all technique selections are justified, scientifically sound, and aligned with ICH Q2(R1), USP, and other pharmacopeial requirements.
5. Procedure
5.1 Preliminary Assessment
- Obtain product-specific information:
- Physicochemical characteristics (solubility, pKa, UV absorbance, volatility)
- Therapeutic concentration range
- Formulation matrix (excipients, solvents)
- Review available pharmacopoeial monographs or prior validated methods.
5.2 Technique Selection Matrix
Use the following criteria to select the most appropriate analytical technique:
| Technique | Ideal For | Limitations |
|---|---|---|
| HPLC | Non-volatile, polar compounds | Requires mobile phase optimization |
| GC | Volatile and thermally stable analytes | Not suitable for thermolabile APIs |
| UV-Vis | Compounds with chromophores | Lacks selectivity, prone to interference |
| FTIR | Structural characterization | Limited quantification capability |
| Titration | Acid/base or redox-active analytes | Low sensitivity, matrix-dependent |
| Potentiometry | pH and ionic measurements | Not selective for complex mixtures |
5.3 Selection Process
- Document justification for selected technique in Annexure-1.
- If multiple techniques are applicable, conduct parallel trials for sensitivity, precision, and specificity.
- Select technique providing best balance of robustness, sensitivity, specificity, and cost-effectiveness.
5.4 Case Examples
- API-A: UV method selected due to strong absorbance at 254 nm and minimal matrix interference.
- API-B: GC selected for quantifying residual solvents due to volatility profile.
- API-C: HPLC selected due to presence of multiple closely eluting impurities.
5.5 Documentation
- Record selection process, rationale, trial results, and risk assessment in Annexure-2.
- Store supporting chromatograms, spectrums, and validation feasibility data with the technique evaluation file.
5.6 Approval
- Submit the documented technique selection sheet to QA for review.
- Obtain final approval from AMD Head before initiating full method development.
6. Abbreviations
- API: Active Pharmaceutical Ingredient
- HPLC: High Performance Liquid Chromatography
- GC: Gas Chromatography
- UV: Ultraviolet Spectroscopy
- FTIR: Fourier Transform Infrared Spectroscopy
7. Documents
- Annexure-1: Analytical Technique Selection Sheet
- Annexure-2: Comparative Technique Evaluation Summary
8. References
- ICH Q2(R1) – Validation of Analytical Procedures
- USP General Chapters <1225>, <621>
- FDA Guidance for Industry – Analytical Procedures and Methods Validation
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | Priya Menon | Harshad Shinde | Dr. Ritu Goyal |
| Designation | Scientist – AMD | QA Lead | Department Head |
| Department | Analytical Method Development | Quality Assurance | Analytical Method Development |
11. Annexures
Annexure-1: Analytical Technique Selection Sheet
| Product Name | Technique Considered | Selected Technique | Justification |
|---|---|---|---|
| Paracetamol Tablets | UV, HPLC | UV | Strong UV absorbance; minimal interference; cost-effective |
| Metronidazole API | GC, HPLC | HPLC | Non-volatile; impurity profiling needed |
Annexure-2: Comparative Technique Evaluation Summary
| Technique | LOD (µg/mL) | Precision (% RSD) | Specificity | Decision |
|---|---|---|---|---|
| UV | 0.5 | 1.2 | Low | Rejected |
| HPLC | 0.1 | 0.8 | High | Selected |
Revision History
| Revision Date | Revision No. | Change Description | Reason | Approved By |
|---|---|---|---|---|
| 01/06/2025 | 2.0 | Incorporated selection matrix and Annexure-2 | Annual Review | Dr. Ritu Goyal |
| 04/08/2022 | 1.0 | Initial Issue | New SOP | QA Head |