ensures the moisture sensitivity profile of pharmaceutical substances is well characterized.

2. Scope

This SOP applies to all solid APIs and formulated pharmaceutical products tested in the Analytical Method Development (AMD) department. The procedure includes exposure to controlled humidity environments such as 75% RH and 90% RH for defined durations.

3. Responsibilities

• Analytical Scientist: Designs the study protocol, selects method, and interprets results.
• Lab Analyst: Prepares samples, conducts exposure, and performs analysis.
• QA Officer: Reviews testing records and ensures compliance with approved protocols.
• Head – AMD: Approves final degradation report and confirms regulatory readiness.

4. Accountability

The Head of AMD is accountable for ensuring that all humidity stress studies are conducted as per ICH Q1A(R2) and internal R&D guidelines, and that validated methods are used for evaluation.

5. Procedure

5.1 Protocol Development

1. Prepare a protocol that includes:
   • Sample ID, description, and quantity
   • Humidity condition (e.g., 75% RH, 90% RH)
   • Temperature (25°C/40°C)
   • Exposure duration (e.g., 24h, 48h, 72h)
   • Analytical test method
2. Obtain review and approval before initiating study.

5.2 Exposure Conditions

1. Place samples in a controlled humidity chamber set to desired RH (typically 75% or 90%) and temperature (25°C or 40°C).
2. Use open petri dishes or uncovered vials for solid samples to maximize exposure.
3. Record environmental parameters at regular intervals using calibrated hygrometer and thermometer.
4. Document placement and retrieval times in Annexure-1: Humidity Exposure Log.

5.3 Sample Retrieval and Preparation

1. After the specified exposure period, remove samples from chamber.
2. Immediately weigh and prepare samples for analysis using validated diluent or mobile phase.
3. Filter solutions through 0.45 µm PVDF syringe filter before analysis.

5.4 Analysis and Evaluation

1. Analyze the sample using a validated HPLC/UPLC or UV method for:
   • Assay (%)
   • Degradation products (new peaks)
   • Moisture content if required (via Karl Fischer titration)
2. Compare chromatograms of stressed and control samples.
3. Log data in Annexure-2: Degradation Summary Sheet.

5.5 Acceptance Criteria and Interpretation

1. Degradation should fall within 5–20% to confirm method sensitivity.
2. Main peak must remain unaffected with acceptable peak purity.
3. Presence of new peaks indicates potential moisture-induced degradation pathways.

6. Abbreviations

• RH: Relative Humidity
• HPLC: High-Performance Liquid Chromatography
• UPLC: Ultra-Performance Liquid Chromatography
• PDA: Photodiode Array
• SOP: Standard Operating Procedure

7. Documents

1. Humidity Exposure Log – Annexure-1
2. Degradation Summary Sheet – Annexure-2

8. References

• ICH Q1A(R2) – Stability Testing of New Drug Substances and Products
• ICH Q2(R2) – Validation of Analytical Procedures
• USP <671> – Containers and Storage Conditions

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Humidity Exposure Log

Sample ID	RH (%)	Temp (°C)	Start Time	End Time	Observed Changes	Analyst
HUM-API-007	90	40	10:00	10:00 (Next Day)	Clumping Observed	Rajesh Kumar

Annexure-2: Degradation Summary Sheet

Sample ID	Assay (%)	% Degradation	New Peaks Observed	Peak Purity	Conclusion
HUM-API-007	89.5	10.5	2	Pass	Humidity sensitive

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
04/05/2025	2.0	Expanded temperature and RH combinations; added Karl Fischer analysis step	Method enhancement for sensitive APIs