Chemical Stability Testing of Emulsion Formulations
1) Purpose
The purpose of this SOP is to outline the procedure for conducting chemical stability testing on emulsion formulations. This testing ensures that the active pharmaceutical ingredient (API) and excipients within the emulsion remain stable, maintaining efficacy and safety over time.
2) Scope
This SOP applies to all personnel involved in the chemical stability testing of emulsion formulations, including formulation scientists and quality control teams. It focuses on the testing of APIs and excipients for degradation and other chemical changes that could compromise the formulation’s integrity.
3) Responsibilities
- Formulation Scientists: Responsible for preparing emulsion samples for chemical stability testing and ensuring sample uniformity.
- QC Team: Responsible for conducting chemical stability tests at defined intervals and documenting the results.
- QA Team: Responsible for reviewing and approving the stability study results and ensuring compliance with GMP standards.
4) Procedure
4.1 Sample Preparation
- 4.1.1 Prepare emulsion formulations as per the manufacturing protocol, ensuring sample uniformity for all test groups.
- 4.1.2 Label the samples with the batch number, preparation date, and storage conditions.
- 4.1.3 Store samples under different storage conditions, such as 25°C/60% RH, 40°C/75% RH, and 4°C as a control.
4.2 Chemical Stability Testing Parameters
The following parameters should be monitored during chemical stability testing:
- 4.2.1 API Content: Measure the concentration of the active pharmaceutical ingredient using high-performance liquid chromatography (HPLC). Compare the results with the initial concentration to determine any loss in potency.
- 4.2.2 Degradation Products: Monitor the formation of degradation products using HPLC or other suitable methods. Ensure that degradation levels are within acceptable limits as per regulatory guidelines.
- 4.2.3 pH: Measure the pH of the emulsion at regular intervals, as significant changes in pH may indicate chemical instability.
4.3 Sampling and Testing Schedule
- 4.3.1 Initial Test: Conduct chemical stability tests immediately after formulation preparation to establish a baseline.
- 4.3.2 Interim Tests: Perform chemical stability testing at specified intervals (e.g., 1 month, 3 months, 6 months) for samples stored under different conditions.
- 4.3.3 Final Test: Conduct the final test at the end of the study period (e.g., 12 months) to determine long-term chemical stability.
4.4 Data Recording and Analysis
- 4.4.1 Record all test results in the Chemical Stability Test Report (see Annexure 1 for the template).
- 4.4.2 Compare the test results to the baseline values to assess the presence of degradation or chemical changes.
- 4.4.3 Analyze the data to determine the shelf life and overall chemical stability of the emulsion formulation.
4.5 Acceptance Criteria for Stability
The emulsion formulation is considered chemically stable if the following criteria are met throughout the study:
- 4.5.1 The concentration of the API remains within ±10% of the initial value, indicating no significant degradation.
- 4.5.2 Degradation products remain below the acceptable threshold as defined by regulatory guidelines.
- 4.5.3 No significant pH shifts that indicate chemical instability.
5) Abbreviations
- HPLC: High-Performance Liquid Chromatography
- RH: Relative Humidity
- QC: Quality Control
- QA: Quality Assurance
6) Documents
- Chemical Stability Test Report
- Batch Manufacturing Record (BMR)
- HPLC Analysis Report
- pH Measurement Report
7) References
- ICH Q1A: Stability Testing of New Drug Substances and Products
- FDA Guidelines for Stability Testing of Emulsion Formulations
8) SOP Version
Version 1.0
Annexure
Annexure 1: Chemical Stability Test Report Template
| Time Point | Storage Condition | API Content (%) | Degradation Products | pH | Operator Initials |
|---|---|---|---|---|---|
| Initial | 25°C/60% RH | 100% | None | 7.0 | Operator Name |
| 1 Month | 40°C/75% RH | 98% | None | 6.9 | Operator Name |
| 3 Months | 40°C/75% RH | 95% | Trace | 6.8 | Operator Name |