Procedure for Viscosity Testing in Oral Liquids

1) Purpose

The purpose of this SOP is to outline the procedure for testing the viscosity 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 viscosity testing as part of quality control measures to assess flow properties and consistency.

3) Responsibilities

Quality Control (QC) Department: Responsible for performing viscosity testing.
Quality Assurance (QA) Department: Responsible for review and approval of viscosity 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 viscometer according to manufacturer’s instructions.
    4.1.2 Ensure the viscometer spindle is appropriate for the viscosity range of the sample.

4.2 Sample Preparation:
    4.2.1 Allow the oral liquid sample to equilibrate to room temperature if stored under refrigeration.
    4.2.2 Transfer a sufficient amount of sample into the viscometer chamber.

4.3 Viscosity Measurement:
    4.3.1 Insert the viscometer spindle into the sample, ensuring it is fully submerged and centered.
    4.3.2 Start the viscometer and allow sufficient time for stable readings to be obtained.
    4.3.3 Record the viscosity reading displayed on the viscometer.

4.4 Calibration Verification:
    4.4.1 Verify viscometer calibration periodically using standard viscosity reference fluids.
    4.4.2 Adjust viscometer if readings deviate from expected values.

4.5 Data Recording:
    4.5.1 Record the viscosity 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 viscosity 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 viscosity 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 Viscosity Testing Report summarizing test procedures, results, and conclusions.
    4.8.2 Include any corrective actions or recommendations based on viscosity 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

Viscosity Testing Report
Calibration Records
Sample Testing Data

7) Reference, if any

USP (insert appropriate reference for viscosity testing)
FDA Guidance for Industry – Container Closure Systems for Packaging Human Drugs and Biologics

8) SOP Version

Version 1.0