Development Team: Ensures that the selected packaging components (e.g., cans, valves, actuators) do not react negatively with the formulation components.

4. Accountability

The R&D Manager is accountable for ensuring that this SOP is followed during compatibility studies for aerosol products. The overall compliance to this SOP is under the supervision of the Quality Assurance (QA) Manager.

5. Procedure

5.1. Selection of Components for Compatibility Testing

1. Identify all components involved in the formulation, including active ingredients, excipients, propellants, and packaging materials (e.g., cans, valves, actuators).
2. Select the components that need to be tested for compatibility based on their interaction potential, chemical reactivity, and influence on the formulation’s stability and performance.
3. Determine the need for testing the following types of interactions:
   • Chemical compatibility: Ensuring that there are no undesirable reactions (e.g., degradation or contamination) between formulation components.
   • Physical compatibility: Ensuring that the components mix or blend without phase separation, crystallization, or settling.
   • Functional compatibility: Ensuring that the components work together properly during aerosol actuation and delivery (e.g., proper spray pattern, valve function).

5.2. Conducting Compatibility Tests

1. Prepare compatibility test samples by combining the selected components in appropriate proportions according to the formulation’s requirements.
2. Perform the following compatibility tests:
   • Visual Inspection: Observe the test samples for any changes in appearance, such as color, phase separation, or precipitation, after a specified period.
   • Stability Testing: Test the stability of the formulation components over time under different environmental conditions (e.g., temperature, humidity). Ensure that the formulation remains stable, without degradation or loss of efficacy.
   • Physical Testing: Assess the formulation for proper dispersion, solubility, and uniformity of content. This may involve examining the consistency, viscosity, or dispersion properties of the formulation.
   • Performance Testing: Evaluate the functional performance of the formulation in the aerosol canister. This includes the spray pattern, droplet size, and delivery consistency during actuation. Conduct tests for valve and actuator functionality to ensure proper operation.
   • Compatibility with Packaging: Assess the interaction between the formulation and packaging components (e.g., can, valve, actuator). Ensure that there is no leaching, corrosion, or physical damage to the packaging material.
3. Record all observations, measurements, and any deviations from expected results in the Compatibility Testing Log (Annexure-1).

5.3. Data Analysis and Interpretation

1. Analyze the results of the compatibility tests to identify any interactions between formulation components and packaging materials.
2. If any compatibility issues are detected (e.g., instability, separation, corrosion), initiate further investigation to determine the root cause and assess the impact on product safety and performance.
3. Based on the test results, determine whether adjustments to the formulation or packaging materials are necessary to prevent adverse reactions.
4. Document the findings and conclusions in the Compatibility Study Report (Annexure-2), including any proposed changes or recommendations for the formulation or packaging materials.

5.4. Stability Testing of Compatible Formulation

1. Once compatibility is confirmed, conduct additional stability testing to verify that the formulation maintains its integrity and performance under long-term storage conditions.
2. Test the formulation at various time intervals (e.g., 0, 3, 6, 9, and 12 months) under accelerated conditions (e.g., 40°C ± 2°C and 75% RH ± 5%) to simulate real-world storage conditions.
3. Monitor the product for any signs of degradation or performance issues, including changes in spray pattern, appearance, or valve functionality. Record the results in the Stability Testing Log (Annexure-3).

5.5. Corrective and Preventive Actions (CAPA)

1. If compatibility issues are discovered during testing, initiate corrective actions to resolve the issue. This could involve reformulating the product or selecting alternative materials.
2. Preventive actions should be implemented to minimize the risk of similar issues arising in future formulations. This may include improving material selection processes, refining formulation techniques, or updating packaging materials.
3. Document all corrective and preventive actions in the CAPA Log (Annexure-4) and monitor the effectiveness of these actions during subsequent testing.

6. Abbreviations

• GMP: Good Manufacturing Practice
• QC: Quality Control
• CAPA: Corrective and Preventive Actions
• R&D: Research and Development

7. Documents

1. Compatibility Testing Log (Annexure-1)
2. Compatibility Study Report (Annexure-2)
3. Stability Testing Log (Annexure-3)
4. CAPA Log (Annexure-4)

8. References

This SOP is based on the following regulatory guidelines and industry standards:

• Good Manufacturing Practice (GMP) Guidelines
• FDA Code of Federal Regulations (CFR) Title 21, Part 211
• ISO 9001:2015 – Quality Management Systems

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Compatibility Testing Log

Test Parameter	Test Date	Test Result	Observations	Tested By
Viscosity	06/02/2025	Pass	No visible change	Rajesh Patel

Annexure-2: Compatibility Study Report

Batch No.	Product Name	Compatibility Test Result	Approval Date
12345	Example Aerosol	Compatible	06/02/2025

Annexure-3: Stability Testing Log

Test Parameter	Test Date	Test Result	Remarks	Tested By
Spray Pattern	06/02/2025	Pass	No clogging	Rajesh Patel

Annexure-4: CAPA Log

Issue	Root Cause	Corrective Action	Preventive Action	Follow-up Date
Phase separation	Improper mixing	Reformulated	Improved mixing process	06/03/2025

12. Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By	Page No.	Ref. Point No.	Details of Revision
01/01/2024	V 1.0	Initial Release	First Issue	Anjali Sharma	Page 1	[Ref Point]	First Release
01/01/2025	V 2.0	Updated compatibility study process	To comply with updated GMP regulations	Anjali Sharma	Page 1	[Ref Point]	Updated procedures