and process-related impurities.

2. Scope

This SOP is applicable to the Analytical Method Development (AMD) laboratory responsible for designing and optimizing LC-MS/MS methods used for impurity profiling of active pharmaceutical ingredients (API), excipients, and finished dosage forms.

3. Responsibilities

• Analytical Scientist: Develops and optimizes LC-MS/MS methods, prepares method development and validation reports.
• Mass Spectrometry Specialist: Supports selection of ionization technique, fragmentation settings, and spectral interpretation.
• QA Officer: Reviews method protocols, reports, and ensures compliance with GMP, ICH Q3A/Q3B guidelines.
• Head – AMD: Approves methods for use in stability studies, regulatory filings, and impurity qualification.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring that LC-MS/MS methods for impurity profiling are developed, validated, and documented in accordance with international regulatory standards and internal quality systems.

5. Procedure

5.1 Method Planning and Pre-Development

1. Review target compound structure, known process impurities, degradants, and expected mass fragments.
2. Determine detection limits required based on ICH Q3A/Q3B thresholds (e.g., 0.05%, 0.1%, 0.2%).
3. Choose suitable ionization technique: ESI (Electrospray Ionization) or APCI (Atmospheric Pressure Chemical Ionization).
4. Select MS mode: Full scan, SIM (Selected Ion Monitoring), or MRM (Multiple Reaction Monitoring) depending on analyte complexity.

5.2 LC Conditions Selection

1. Use reversed-phase C18 columns (e.g., 50 x 2.1 mm, 1.7 µm) for broad separation capability.
2. Select mobile phase:
   • Water with 0.1% formic acid (A)
   • Acetonitrile with 0.1% formic acid (B)
3. Develop gradient program (e.g., 5% B to 95% B over 15 min) to resolve impurities.
4. Set flow rate between 0.2 to 0.4 mL/min depending on column and system pressure limits.

5.3 MS/MS Parameter Optimization

1. Infuse standard solutions (1–10 µg/mL) to identify precursor ions (m/z).
2. Perform product ion scan to determine suitable fragment ions (Q3 transitions).
3. Optimize collision energy (CE), declustering potential (DP), and entrance potential (EP).
4. Create MRM transitions for all known impurities and API if quantification is required.
5. Use Annexure-1: MS Parameter Optimization Log.

5.4 Sample Preparation

1. Dissolve samples in appropriate solvent (e.g., methanol, acetonitrile-water mix).
2. Filter through 0.22 µm PVDF or nylon filters.
3. If matrix interference is observed, perform SPE (Solid Phase Extraction) cleanup.

5.5 Method Validation

1. Perform validation as per ICH Q2(R2) for:
   • LOD and LOQ
   • Linearity (R² ≥ 0.999)
   • Precision (intra-day and inter-day)
   • Accuracy (recovery within 90%–110%)
   • Specificity (no interference at impurity retention times)
2. Document results in Annexure-2: Validation Summary Sheet.

5.6 System Suitability and Data Handling

1. Inject system suitability mixture prior to batch analysis to confirm:
   • Resolution ≥ 1.5 between impurities
   • S/N ratio ≥ 10 for LOD level
2. Process data using appropriate software with audit trails enabled.
3. Quantify impurities using external calibration or response factor approach.
4. Prepare Annexure-3: Impurity Quantification Log.

6. Abbreviations

• LC-MS/MS: Liquid Chromatography-Tandem Mass Spectrometry
• ESI: Electrospray Ionization
• MRM: Multiple Reaction Monitoring
• LOD: Limit of Detection
• LOQ: Limit of Quantification
• SOP: Standard Operating Procedure

7. Documents

1. MS Parameter Optimization Log – Annexure-1
2. Validation Summary Sheet – Annexure-2
3. Impurity Quantification Log – Annexure-3

8. References

• ICH Q3A(R2) – Impurities in New Drug Substances
• ICH Q3B(R2) – Impurities in New Drug Products
• ICH Q2(R2) – Validation of Analytical Procedures
• FDA Guidance on Mass Spectrometry for Regulatory Submissions

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: MS Parameter Optimization Log

Impurity	Precursor Ion (m/z)	Product Ion (m/z)	Collision Energy (eV)	Analyst
Imp-01	279.1	121.0	25	Sunita Reddy

Annexure-2: Validation Summary Sheet

Parameter	Result	Acceptance	Status
LOD	0.005%	≤ 0.05%	Pass
Linearity	R² = 0.9997	≥ 0.999	Pass

Annexure-3: Impurity Quantification Log

Batch No.	Impurity	Amount (%)	LOD/LOQ Met	Analyst
API-2025-045	Imp-03	0.12%	Yes	Rajesh Kumar

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Added validation log and impurity quantification section	Annual Review