pharmacopeial standards.

2. Scope

This SOP is applicable to Analytical Method Development (AMD) personnel performing impurity profiling of nasal formulations during product development, stability testing, and regulatory submissions.

3. Responsibilities

• Analytical Scientist: Performs impurity profiling using validated methods and documents results.
• QC Analyst: Assists with sample preparation, instrument calibration, and system suitability checks.
• QA Executive: Verifies impurity data for compliance with regulatory thresholds and approves reports.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring that impurity analysis methods are scientifically validated, robust, and compliant with international guidelines.

5. Procedure

5.1 Sample Preparation

1. Shake the nasal spray bottle and actuate 5 sprays into a 100 mL volumetric flask.
2. Make up the volume with mobile phase or suitable diluent (e.g., Water:ACN 50:50).
3. Filter through 0.22 µm PVDF or nylon syringe filter.

5.2 Standard Preparation

1. Prepare individual impurity standards and API standard at known concentrations.
2. Use concentrations equivalent to reporting threshold (e.g., 0.05% for known impurities).

5.3 Chromatographic Conditions

1. Column: C18 (150 mm × 4.6 mm, 5 µm)
2. Mobile Phase: Gradient of water with 0.1% formic acid (A) and acetonitrile (B)
3. Flow Rate: 1.0 mL/min
4. Detector: UV at 210 nm or diode-array detector (DAD)
5. Run Time: 60 minutes for extended profiling

5.4 System Suitability

1. Inject standard mix solution containing API and known impurities.
2. Ensure resolution (Rs) ≥ 2.0 between peaks, %RSD ≤ 2.0% for five replicate injections.

5.5 Method Validation

1. Validate the method for:
   • Specificity
   • LOD/LOQ (S/N ratio ≥ 3 and 10 respectively)
   • Linearity (r ≥ 0.999) from 0.05% to 1.5%
   • Accuracy (recovery 90–110%)
   • Precision (RSD ≤ 5% for impurity peaks)

5.6 Data Interpretation

1. Compare unknown peaks with retention times of known impurities.
2. Calculate impurity content as:
   
   % Impurity = (Area of impurity / Area of API) × (Concentration of API / Concentration of impurity standard) × 100
3. Report total impurities, known identified impurities, and unknown impurities.

6. Abbreviations

• HPLC: High Performance Liquid Chromatography
• API: Active Pharmaceutical Ingredient
• LOD: Limit of Detection
• LOQ: Limit of Quantification
• Rs: Resolution

7. Documents

1. Impurity Analysis Data Log – Annexure-1
2. System Suitability Log – Annexure-2
3. Impurity Validation Report – Annexure-3

8. References

• ICH Q3B(R2): Impurities in New Drug Products
• USP <621>: Chromatography
• FDA Guidance for Industry: Nasal Spray Drug Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Swati Deshmukh	Ravi Choudhary	Sunita Reddy
Designation	Analytical Scientist	QA Reviewer	Head – AMD
Department	Analytical Method Development	QA	Analytical Method Development

11. Annexures

Annexure-1: Impurity Analysis Data Log

Peak Name	RT (min)	Area	% Impurity	Status
Impurity A	12.3	345	0.12%	Pass
Unknown-1	22.8	178	0.07%	Pass

Annexure-2: System Suitability Log

Injection	RT (API)	RT (Impurity A)	Rs	% RSD
1	9.8	12.3	3.5	1.6

Annexure-3: Impurity Validation Report

Impurity profiling method validated for nasal spray product NS-01. Linearity from 0.05% to 1.5% with correlation coefficient 0.9997. Recovery of Impurity A: 98.7%. LOD: 0.015%, LOQ: 0.045%. Method suitable for stability and release testing.

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
21/05/2025	2.0	Expanded section on unknown impurity evaluation and annexures added	Annual Review	Sunita Reddy
02/03/2022	1.0	Initial SOP Release	New SOP	QA Head