is applicable to Analytical Method Development (AMD) teams involved in forced degradation studies of drug substances and products during pre-formulation, formulation development, and stability testing in accordance with ICH Q1A(R2).

3. Responsibilities

• Analytical Scientist: Conducts oxidation stress studies, monitors degradation, and interprets chromatographic/spectral data.
• Instrument Operator: Performs LC-MS/NMR analysis for pathway elucidation.
• QA Officer: Ensures documentation accuracy and compliance with stability study requirements.
• Head – AMD: Reviews and approves degradation pathway reports and justifies oxidation-specific degradation mechanisms.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring scientifically justified oxidative stress testing and accurate profiling of degradation pathways under regulatory guidelines.

5. Procedure

5.1 Selection of Samples

1. Select API and/or finished drug product samples suitable for stress degradation studies.
2. Use unformulated API, formulation blend, and final product to evaluate matrix impact on oxidation.
3. Record in Annexure-1: Sample Log for Oxidative Study.

5.2 Stress Conditions

1. Oxidizing Agent: Use hydrogen peroxide (H₂O₂) at 3%, 10%, or 30% (v/v) depending on API sensitivity.
2. Exposure Time: Typically 1–24 hours under ambient temperature or elevated conditions (40–60°C).
3. Controls: Include non-stressed sample and vehicle blank.
4. Document details in Annexure-2: Oxidation Reaction Record.

5.3 Sample Preparation and Analysis

1. Neutralize excess peroxide using sodium bisulfite or catalase enzyme (if required).
2. Analyze the degraded and control samples using validated HPLC/UPLC with PDA or MS detection.
3. Compare peak profiles, retention times, and UV spectra for new peaks.
4. Assess peak purity using PDA or MS-based purity assessment tools.
5. Document in Annexure-3: Oxidative Degradation Chromatographic Summary.

5.4 Identification of Degradation Products

1. Use LC-MS/MS to determine molecular weights and fragmentation patterns of major degradation products.
2. Compare with known oxidation products (e.g., sulfoxide, N-oxide, aldehyde formation).
3. Isolate unknown degradants if needed and characterize using NMR or FTIR.
4. Summarize data in Annexure-4: Degradation Pathway Characterization Sheet.

5.5 Pathway Profiling and Risk Assessment

1. Construct oxidative degradation pathway based on observed structures and reaction types.
2. Identify sensitive moieties in the molecule (e.g., thiols, amines, phenols).
3. Document safety impact and toxicological relevance per ICH M7 if degradation product has structural alerts.
4. Report outcome in Annexure-5: Oxidative Degradation Pathway Report.

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• LC-MS: Liquid Chromatography-Mass Spectrometry
• NMR: Nuclear Magnetic Resonance
• PDA: Photodiode Array
• ICH: International Council for Harmonisation
• SOP: Standard Operating Procedure

7. Documents

1. Sample Log for Oxidative Study – Annexure-1
2. Oxidation Reaction Record – Annexure-2
3. Oxidative Degradation Chromatographic Summary – Annexure-3
4. Degradation Pathway Characterization Sheet – Annexure-4
5. Oxidative Degradation Pathway Report – Annexure-5

8. References

• ICH Q1A(R2) – Stability Testing of New Drug Substances and Products
• ICH M7 – Assessment and Control of DNA Reactive Impurities
• USP <1225> – Validation of Compendial 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: Sample Log for Oxidative Study

Date	Sample ID	Batch No.	Matrix	Assigned By
18/05/2025	OXD-API-07	AXR/045	Pure API	Rajesh Kumar

Annexure-2: Oxidation Reaction Record

Date	H2O2 Conc.	Volume Used	Exposure Time	Neutralized
18/05/2025	10%	5 mL	4 hours	Yes

Annexure-3: Oxidative Degradation Chromatographic Summary

Peak No.	RT (min)	RRT	Area %	Degradation Product
2	6.72	1.21	0.56%	Unknown (DGP-OX-01)

Annexure-4: Degradation Pathway Characterization Sheet

Impurity Code	m/z	Fragmentation	Functional Group	Structure Assigned
DGP-OX-01	315	Loss of –CH3	Sulfoxide	Yes

Annexure-5: Oxidative Degradation Pathway Report

The oxidative stress study of API revealed two major degradation products. LC-MS and NMR confirmed sulfoxide and N-oxide formation. Structures were consistent with oxidation-prone functional groups. No genotoxic alerts detected.

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Expanded section on pathway mapping and impurity structural assignment	Annual Update