Procedure for Rheological Testing of Gels

1) Purpose

The purpose of this SOP is to outline the procedure for performing rheological testing on gel pharmaceutical products to ensure compliance with specifications and regulatory requirements.

2) Scope

This SOP applies to all gel pharmaceutical products requiring rheological testing as part of quality control measures to assess viscosity and consistency.

3) Responsibilities

Quality Control (QC) Department: Responsible for performing rheological testing.
Quality Assurance (QA) Department: Responsible for review and approval of rheological testing procedures and results.
Manufacturing Department: Responsible for providing gel samples and support during testing.

4) Procedure

4.1 Equipment Preparation:
    4.1.1 Calibrate the rheometer according to manufacturer’s instructions.
    4.1.2 Ensure the spindle or cone-plate geometry is appropriate for gel viscosity range.

4.2 Sample Preparation:
    4.2.1 Allow the gel sample to equilibrate to room temperature if stored under refrigeration.
    4.2.2 Transfer a sufficient amount of sample onto the rheometer platform.

4.3 Rheological Measurement:
    4.3.1 Set the rheometer to the appropriate settings (e.g., shear rate, temperature).
    4.3.2 Start the measurement and allow the rheometer to record viscosity and shear stress values.
    4.3.3 Perform tests at multiple shear rates if required by specifications.

4.4 Data Analysis:
    4.4.1 Analyze rheological data to determine viscosity profile, shear thinning behavior, and other relevant parameters.
    4.4.2 Compare results against acceptance criteria and specifications.

4.5 Calibration Verification:
    4.5.1 Verify rheometer calibration periodically using standard reference materials.
    4.5.2 Adjust rheometer settings or calibration if readings deviate from expected values.

4.6 Reporting:
    4.6.1 Prepare a Rheological Testing Report summarizing test procedures, results, and conclusions.
    4.6.2 Include any corrective actions or recommendations based on rheological testing findings.
    4.6.3 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

Rheological Testing Report
Calibration Records
Sample Testing Data

7) Reference, if any

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

8) SOP Version

Version 1.0