Standard Operating Procedure (SOP) for Stability Testing of Screening Formulations

1) Purpose

The purpose of this Standard Operating Procedure (SOP) is to outline the procedure for stability testing of screening formulations in pharmaceutical development. Stability testing is crucial for evaluating the shelf life, degradation profiles, and storage conditions of drug formulations. This SOP provides standardized procedures for conducting stability studies on screening formulations to ensure that they maintain their efficacy, safety, and quality over time under different conditions.

2) Scope

This SOP applies to all personnel involved in the stability testing of screening formulations. It covers the preparation of samples, selection of stability conditions, testing methods, and data analysis. This SOP is relevant to formulation scientists, laboratory technicians, project managers, and quality assurance (QA) personnel involved in preclinical and clinical formulation development.

3) Responsibilities

• Formulation Scientists: Oversee the stability testing process, ensuring that the formulations are tested under the correct conditions and that the data generated is accurate and reliable.
• Laboratory Technicians: Prepare the samples and conduct the stability testing according to the approved protocol, ensuring all conditions are met.
• Project Managers: Coordinate the stability testing activities, ensuring that the testing is conducted according to the study timeline and that results are communicated to relevant teams.
• Quality Assurance (QA): Review the stability testing process and ensure compliance with Good Laboratory Practice (GLP) standards. Ensure that the data is recorded, documented, and stored appropriately.
• Regulatory Affairs Personnel: Ensure that stability testing complies with regulatory guidelines and that the results are suitable for inclusion in regulatory submissions.

4) Procedure

The following steps outline the procedure for stability testing of screening formulations:

1. Step 1: Formulation Sample Preparation
   1. Prepare screening formulations according to the approved formulation protocols, ensuring accurate measurements and mixing of ingredients.
   2. Label each sample with the formulation type, batch number, preparation date, and storage conditions to ensure traceability during the stability study.
   3. Ensure that sufficient quantities of the formulation are prepared to allow for testing at multiple time points throughout the stability study.
2. Step 2: Selection of Stability Conditions
   1. Select appropriate stability testing conditions based on the expected storage conditions of the formulations, such as temperature (e.g., 4°C, room temperature, or accelerated conditions at 40°C) and humidity levels (e.g., 75% RH).
   2. Determine the duration of the stability study based on the study objectives, but typically stability studies span 1 to 6 months for preliminary results or up to 12 months for final formulations.
   3. Ensure that stability conditions align with regulatory guidelines for preclinical testing or clinical use, as applicable.
3. Step 3: Stability Testing Procedure
   1. Store the prepared formulation samples under the selected stability conditions and monitor them at regular intervals, such as 0, 1, 2, 3, 6, and 12 months.
   2. At each time point, collect a sample of the formulation for testing, ensuring that the sample is representative of the batch.
   3. Perform necessary tests on the formulation samples, which may include visual inspection (e.g., appearance, color, and phase separation), chemical analysis (e.g., active pharmaceutical ingredient (API) content), and physical tests (e.g., pH, viscosity, particle size).
4. Step 4: Analytical Testing
   1. Use validated analytical methods, such as High-Performance Liquid Chromatography (HPLC) or UV-Vis spectroscopy, to measure the stability of the API in the formulation over time.
   2. Test for any degradation products or impurities that may form over time and assess the extent of degradation at each time point.
   3. Perform statistical analysis of the data to determine the stability profile of the formulation, including degradation rates and the formulation’s shelf life under different conditions.
5. Step 5: Data Interpretation and Reporting
   1. Review the stability test results to determine whether the formulation meets the predefined stability criteria (e.g., retention of API content, no significant degradation, acceptable physical properties).
   2. Interpret the results to evaluate the formulation’s stability under the selected conditions and determine the expected shelf life of the product.
   3. Prepare a stability report that summarizes the data, including test conditions, test results, observations, and conclusions.
   4. Document any deviations from the stability protocol and provide justification for any changes or adjustments to the test procedure or conditions.
6. Step 6: Storage of Samples
   1. Store all formulation samples under the appropriate conditions after stability testing, ensuring that they are securely labeled and stored in a controlled environment.
   2. Ensure that any remaining samples are stored according to internal policies for sample retention and are available for future analysis if necessary.
7. Step 7: Documentation and Record Keeping
   1. Document all stability testing activities, including sample preparation, testing conditions, analytical results, and observations. Maintain detailed records of all test dates, times, and actions taken during the study.
   2. Ensure that all records are signed and dated by the personnel conducting the tests and that they are stored securely in compliance with Good Laboratory Practice (GLP) standards.
   3. Maintain records for regulatory submissions or audits, ensuring that the documentation is accessible for review as required.
8. Step 8: Sample Disposal
   1. Dispose of any remaining samples and testing materials according to safety protocols and regulatory guidelines. Ensure that hazardous materials, if any, are disposed of in compliance with environmental and safety regulations.

5) Documents

The following documents should be maintained during the stability testing of screening formulations:

1. Stability Testing Protocols
2. Sample Preparation Records
3. Stability Testing Logs
4. Analytical Data and Test Results
5. Stability Study Reports
6. Sample Disposal Records

6) Abbreviations

• HPLC: High-Performance Liquid Chromatography
• API: Active Pharmaceutical Ingredient
• GLP: Good Laboratory Practices
• RH: Relative Humidity

7) References

References to regulatory guidelines and scientific literature that support this SOP:

• OECD Guidelines for Good Laboratory Practice (GLP)
• ICH Q1A Stability Testing of New Drug Substances and Products
• FDA Guidelines for Stability Testing

8) Version

Version 1.0: Initial version of the SOP.

9) Annexure

Stability Testing Log Template