Procedure for Evaluating the Effect of pH on Drug Stability
1) Purpose
The purpose of this SOP is to provide a standardized procedure for assessing the impact of pH on the stability of drug substances and products to determine optimal formulation conditions and storage environments.
2) Scope
This SOP applies to all drug substances and products that require evaluation of pH effect on their stability. It is relevant for personnel in quality control, research and development, and regulatory affairs departments.
3) Responsibilities
The responsibilities for assessing the effect of pH on drug stability are as
follows:
- Quality Control Team: To conduct pH stability tests as per the protocol and document results.
- R&D Team: To design the pH stability study protocol and provide technical support.
- Regulatory Affairs Team: To ensure compliance with regulatory guidelines during pH stability testing.
- Stability Study Coordinator: To manage testing schedules, sample management, and data analysis.
4) Procedure
The detailed stepwise procedure for assessing the effect of pH on drug stability is outlined below:
- Preparation of pH Stability Study Protocol:
- 4.1 Define the purpose, scope, and objective of the pH stability study.
- 4.2 Identify the drug substance or product and critical quality attributes (CQAs) to be monitored (e.g., potency, degradation products, solubility).
- 4.3 Determine the pH range to be tested (e.g., pH 2 to 8).
- 4.4 Establish the time points for testing at each pH condition (e.g., 0, 1, 3, 6, 12 months).
- 4.5 Develop a protocol outlining procedures, equipment, and materials required for testing.
- Sample Preparation and Testing:
- 4.6 Prepare solutions of the drug substance or product at different pH levels using appropriate buffers.
- 4.7 Store samples at specified conditions (e.g., room temperature, refrigerated) in stability chambers or other controlled environments.
- 4.8 Retrieve samples at specified time points and perform the required tests (e.g., assay, degradation products, solubility).
- Data Analysis and Interpretation:
- 4.9 Analyze the stability data to identify any trends or deviations caused by pH variations.
- 4.10 Determine the optimal pH conditions for the stability of the drug substance or product.
- 4.11 Document any significant findings or trends in the data.
- Documentation and Reporting:
- 4.12 Compile a comprehensive pH stability study report including objectives, methods, results, and conclusions.
- 4.13 Ensure the report is reviewed and approved by relevant stakeholders.
- 4.14 Submit the report to regulatory bodies or internal stakeholders as required.
- Review and Update:
- 4.15 Regularly review the pH stability study protocol and update it based on new data or regulatory changes.
- 4.16 Archive the approved protocol and report in a controlled document management system.
5) Abbreviations, if any
- CQA: Critical Quality Attribute
6) Documents, if any
- pH Stability Study Protocol
- pH Stability Testing Log Sheets
- pH Stability Study Report Template
7) Reference, if any
- ICH Q1A(R2): Stability Testing of New Drug Substances and Products
8) SOP Version
Version 1.0