Scope

This SOP applies to all method development activities involving chromatographic techniques—High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC)—carried out in the Analytical Method Development department for API and formulation samples.

3. Responsibilities

• Analytical Scientist: Conducts chromatographic optimization trials and documents results.
• Method Development Lead: Reviews system suitability and performance data to finalize parameters.
• QA Reviewer: Verifies data integrity and ensures compliance with regulatory and internal standards.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring that the optimization process is executed, verified, and documented in alignment with ICH Q2(R1), regulatory guidelines, and internal quality policies.

5. Procedure

5.1 Preliminary Setup

1. Gather physicochemical properties of analyte: pKa, solubility, polarity, logP, UV absorbance, boiling point (for GC).
2. Select appropriate column based on analyte characteristics:
   • HPLC: C18, C8, Phenyl, or HILIC based on polarity and retention needs
   • GC: Capillary column (e.g., DB-1, DB-5, FFAP) based on volatility and separation profile

5.2 Mobile Phase and Diluent Selection

1. Choose solvent system (e.g., water:acetonitrile, water:methanol) compatible with analyte solubility and detector requirements.
2. Adjust pH to influence ionization state and retention behavior; use buffer systems like phosphate, acetate, or ammonium formate.
3. Ensure diluent compatibility with both sample and mobile phase to avoid precipitation or baseline drift.

5.3 Flow Rate Optimization

1. Begin trials at standard flow rate (e.g., 1.0 mL/min for HPLC).
2. Assess retention time, peak symmetry, and resolution under increased and decreased flow conditions.
3. Select flow rate that ensures optimal separation and system pressure compliance.

5.4 Column Temperature

1. Study effect of temperature (e.g., 25°C to 45°C) on peak shape, tailing, and baseline noise.
2. Maintain consistent oven temperature for GC methods to ensure reproducibility.

5.5 Detection Parameters

1. HPLC: Select detection wavelength based on analyte’s UV absorbance maximum using UV scan data.
2. GC: Use Flame Ionization Detector (FID) or Thermal Conductivity Detector (TCD) depending on sensitivity and compound class.

5.6 Injection Volume and Sample Load

1. Optimize injection volume (typically 10–20 µL for HPLC) to balance sensitivity and peak shape.
2. Avoid column overloading and ensure linearity within working concentration range.

5.7 System Suitability and Repeatability

1. Evaluate system suitability parameters:
   • Theoretical plates (N)
   • Tailing factor (Tf)
   • Resolution (Rs)
   • Retention time (Rt)
2. Repeat test for minimum six injections to ensure reproducibility.

5.8 Documentation

1. Record all optimization trials, observations, and decisions in Annexure-1.
2. Attach chromatograms, UV scans, and system suitability reports.
3. Summarize the finalized parameters in Annexure-2.

6. Abbreviations

• HPLC: High Performance Liquid Chromatography
• GC: Gas Chromatography
• FID: Flame Ionization Detector
• UV: Ultraviolet
• LOD: Limit of Detection
• Rt: Retention Time

7. Documents

1. Annexure-1: Optimization Trial Log
2. Annexure-2: Finalized Chromatographic Parameters Summary

8. References

• ICH Q2(R1): Validation of Analytical Procedures
• USP General Chapters <621> and <1021>
• FDA Guidance on Analytical Procedure Development

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Aarti Sharma	Rakesh Verma	Dr. Manish Dubey
Designation	Analytical Scientist	QA Reviewer	Head – AMD
Department	Analytical Method Development	Quality Assurance	Analytical Method Development

11. Annexures

Annexure-1: Optimization Trial Log

Trial No.	Parameter Modified	Value	Observation	Conclusion
1	Flow Rate	0.8 mL/min	Better resolution but longer runtime	Not selected
2	Mobile Phase	ACN:Buffer (60:40)	Sharp peaks and symmetry	Selected

Annexure-2: Finalized Chromatographic Parameters Summary

• Column: C18, 150 mm × 4.6 mm, 5 µm
• Mobile Phase: Acetonitrile:Phosphate buffer (60:40, v/v)
• Flow Rate: 1.0 mL/min
• Detection Wavelength: 254 nm
• Injection Volume: 10 µL
• Run Time: 10 min

Revision History

Revision Date	Revision No.	Description	Reason	Approved By
01/06/2025	2.0	Updated trial formats and buffer selection criteria	Annual Review	Dr. Manish Dubey
15/08/2022	1.0	Initial SOP Release	New SOP	QA Head