compliance with ICH Q3C and regulatory expectations.

2. Scope

This procedure applies to the Analytical Method Development (AMD) laboratory for pharmaceutical API and formulation batches containing residual solvents categorized under Class 1, 2, and 3 per ICH Q3C guidelines.

3. Responsibilities

• Analytical Scientist: Responsible for method development, optimization, and validation of GC-MS methods for residual solvent analysis.
• QA Officer: Ensures regulatory compliance by reviewing protocols, data, and final reports.
• GC-MS Analyst: Sets instrument parameters, verifies calibration, and ensures data integrity.
• Head – AMD: Reviews and approves method validation and standard operating procedures.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring validated GC-MS methods for residual solvents are available and compliant with current regulatory standards.

5. Procedure

5.1 Selection of Target Solvents

1. Identify solvents used in the synthesis or formulation from production records.
2. Classify solvents as per ICH Q3C:
   • Class 1: Benzene, Carbon tetrachloride, etc. (to be avoided)
   • Class 2: Methanol, Acetonitrile, Toluene, etc. (to be limited)
   • Class 3: Ethanol, Acetone, etc. (low toxic potential)
3. Establish permissible limits based on daily intake thresholds.

5.2 Sample Preparation

1. Weigh 500–1000 mg of sample into a headspace vial.
2. Add 5 mL of suitable diluent (e.g., DMSO, water, or DMF depending on solubility).
3. Seal vials using crimp-top and magnetic cap; vortex to mix.
4. Include internal standard (e.g., 1-butanol or acetone-d₆).

5.3 GC-MS Method Setup

1. Use a capillary column such as DB-624 (30 m x 0.32 mm x 1.8 µm) for volatile organic compounds.
2. GC Parameters:
   • Carrier gas: Helium at 1.0 mL/min
   • Injection mode: Split or splitless depending on detection limit
   • Injector temp: 200°C
   • Oven program: 40°C (hold 5 min) → 240°C at 10°C/min
3. MS Parameters:
   • Ionization: Electron Impact (EI)
   • Scan range: m/z 30–300
   • Source temp: 230°C
   • Quadrupole temp: 150°C
4. Record details in Annexure-1: GC-MS Method Log.

5.4 Calibration and Standard Curve

1. Prepare calibration standards at 0.5x, 1.0x, and 1.5x of ICH limits.
2. Include internal standard in all calibration solutions.
3. Construct standard curve using peak area ratio (Analyte/IS) vs concentration.
4. R² ≥ 0.995 is required for acceptance.

5.5 Method Validation

1. Validate method parameters per ICH Q2(R2):
   • Specificity
   • Linearity (R² ≥ 0.995)
   • Accuracy (recovery 90%–110%)
   • Precision (RSD ≤ 5%)
   • LOD and LOQ determination
2. Document results in Annexure-2: Validation Report.

5.6 Sample Analysis

1. Analyze sample in triplicate and report mean content for each solvent.
2. Check for co-elution or interference using spiked placebo and blank runs.
3. Calculate residual solvent levels using internal standard calibration.
4. Enter results in Annexure-3: Sample Result Log.

6. Abbreviations

• GC-MS: Gas Chromatography – Mass Spectrometry
• LOD: Limit of Detection
• LOQ: Limit of Quantification
• ICH: International Council for Harmonisation
• IS: Internal Standard
• SOP: Standard Operating Procedure

7. Documents

1. GC-MS Method Log – Annexure-1
2. Validation Report – Annexure-2
3. Sample Result Log – Annexure-3

8. References

• ICH Q3C(R8) – Impurities: Guideline for Residual Solvents
• ICH Q2(R2) – Validation of Analytical Procedures
• USP <467> – Residual Solvents
• FDA Guidance for Industry – Residual Solvents in Drug Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: GC-MS Method Log

Analyte	Retention Time (min)	m/z	IS	Method ID	Analyst
Methanol	3.5	32	1-butanol	GCMS/RS/001	Rajesh Kumar

Annexure-2: Validation Report

Parameter	Result	Acceptance Criteria	Status
Linearity	R² = 0.9975	≥ 0.995	Pass
Recovery	96.2%–102.3%	90%–110%	Pass

Annexure-3: Sample Result Log

Sample ID	Solvent	Amount (ppm)	Limit	Status
API/2025/054	Acetonitrile	38	≤ 410	Complies

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Added internal standard use and detailed validation section	Annual SOP Review