pH Testing Procedures for Pharmaceutical Products
1) Purpose
The purpose of this SOP is to outline the procedure for conducting pH testing of pharmaceutical products to ensure they meet specified pH range requirements for stability and efficacy.
2) Scope
This SOP applies to all pH testing of pharmaceutical products conducted within the manufacturing facility, including raw materials, intermediates, and final products.
3) Responsibilities
– QC personnel are responsible for performing pH tests and documenting the results.
– Laboratory supervisors must ensure proper calibration and maintenance of pH meters.
– QA personnel are responsible for reviewing and approving pH test results.
4) Procedure
1. Preparation for pH Testing
1.1. Ensure the pH meter is calibrated according to the manufacturer’s instructions.
1.1.1. Calibrate the pH meter using standard buffer solutions (e.g., pH 4.0, 7.0, and 10.0).
1.2. Gather all necessary materials, including sample containers, pH electrodes, and buffer solutions.
1.3. Verify that the pH meter is functioning correctly and is clean.
2. Sample Preparation
2.1. Obtain a representative sample of the product to be tested.
2.2. If the sample is a solid, dissolve it in
2.3. Ensure that the sample solution is at room temperature before testing.
3. pH Measurement
3.1. Rinse the pH electrode with distilled water and blot dry with a lint-free tissue.
3.2. Immerse the pH electrode into the sample solution.
3.3. Stir the solution gently to ensure uniformity.
3.4. Wait for the pH reading to stabilize, then record the pH value.
3.5. Rinse the electrode with distilled water between measurements to avoid cross-contamination.
4. Documentation
4.1. Record the pH value, sample identification, batch number, date, and time of the test.
4.2. Include any observations or anomalies encountered during the testing process.
4.3. Ensure the data is recorded in the appropriate laboratory notebook or electronic system.
5. Review and Approval
5.1. Submit the pH test results to the laboratory supervisor for initial review.
5.2. The QA department will perform a final review and approval of the pH test documentation.
6. Maintenance of pH Meter
6.1. Regularly clean and calibrate the pH meter according to the manufacturer’s guidelines.
6.2. Replace the pH electrode as per the recommended frequency or if it shows signs of damage or malfunction.
5) Abbreviations, if any
– QC: Quality Control
– QA: Quality Assurance
6) Documents, if any
– pH Test Record
– Calibration Log
– Laboratory Notebook
7) Reference, if any
– USP <791> pH
– FDA Guidance for Industry: Q2(R1) Validation of Analytical Procedures
8) SOP Version
Version 1.0