Procedure for pH Determination in Oral Liquids
1) Purpose
The purpose of this SOP is to outline the procedure for determining the pH of oral liquid pharmaceutical products to ensure compliance with specifications and regulatory requirements.
2) Scope
This SOP applies to all oral liquid pharmaceutical products requiring pH determination to assess acidity or alkalinity as part of quality control measures.
3) Responsibilities
Quality Control (QC) Department: Responsible for performing pH determination tests.
Quality Assurance (QA) Department: Responsible for review and approval of pH testing procedures and results.
Manufacturing Department: Responsible for providing oral liquid samples and support during testing.
4) Procedure
4.1 Equipment Preparation:
4.1.1 Calibrate the pH meter according to manufacturer’s instructions.
4.1.2 Ensure electrodes are clean and conditioned prior to testing.
4.2 Sample Preparation:
4.2.1 Mix the oral liquid sample thoroughly to ensure homogeneity.
4.2.2 Transfer a representative sample into a clean, dry beaker.
4.3 pH Measurement:
4.3.1 Immerse the pH electrode into the oral liquid sample without touching the bottom or sides of the beaker.
4.3.2 Allow the pH reading to stabilize as per meter instructions, then record the pH value.
4.4 Calibration Verification:
4.4.1 Verify pH meter calibration periodically during testing with standard buffer solutions.
4.4.2 Adjust pH meter if readings deviate from expected values.
4.5 Data Recording:
4.5.1 Record the pH value obtained from each sample tested.
4.5.2 Document any observations or deviations from expected results.
4.6 Reproducibility Testing:
4.6.1 Repeat pH measurements on the same sample to confirm reproducibility.
4.6.2 Compare results and ensure consistency within acceptable limits.
4.7 Data Analysis:
4.7.1 Compile and review pH measurement data, including initial readings, calibration checks, and reproducibility testing results.
4.7.2 Analyze data against acceptance criteria and specifications.
4.8 Reporting:
4.8.1 Prepare a pH Determination Report summarizing test procedures, results, and conclusions.
4.8.2 Include any corrective actions or recommendations based on pH measurement findings.
4.8.3 Submit the report to QA for review and approval and maintain records as per facility procedures.
5) Abbreviations, if any
QC: Quality Control
QA: Quality Assurance
6) Documents, if any
pH Determination Report
Calibration Records
Sample Testing Data
7) Reference, if any
USP (insert appropriate reference for pH testing)
FDA Guidance for Industry – Container Closure Systems for Packaging Human Drugs and Biologics
8) SOP Version
Version 1.0
