Standard Operating Procedure for Lotion Rheological Testing

1) Purpose

The purpose of this SOP is to outline the procedure for conducting rheological testing of lotions to assess their flow properties and ensure consistent product quality.

2) Scope

This SOP applies to all personnel involved in the rheological testing of lotions within the pharmaceutical manufacturing facility.

3) Responsibilities

The responsibilities for executing this SOP are as follows:

Laboratory Analysts:

• Perform rheological tests according to this SOP and document results accurately.
• Ensure all rheological testing equipment is calibrated and maintained.

Quality Control Personnel:

• Review and verify rheological test results for accuracy and compliance with specifications.

Quality Assurance Personnel:

• Ensure that the rheological testing program complies with regulatory requirements.

4) Procedure

4.1 Pre-Testing Preparation:

• Ensure the rheometer is calibrated and in good working condition.
• Prepare the lotion samples according to the specified sampling plan.
• Bring the lotion samples to the specified temperature for testing, typically 25°C.

4.2 Rheological Testing Process:

1. Equipment Setup:
   • Set up the rheometer according to the manufacturer’s instructions.
   • Select the appropriate geometry (cone-plate, parallel plate, etc.) for the lotion being tested.
   • Verify that the rheometer is level and properly secured.
2. Sample Preparation:
   • Stir the lotion sample gently to ensure uniformity.
   • Transfer an adequate amount of lotion into the rheometer sample holder.
3. Conducting the Test:
   1. Load the sample onto the rheometer, ensuring it is properly placed without air bubbles.
   2. Set the testing parameters (shear rate, shear stress, frequency, etc.) as per the product specifications.
   3. Start the rheometer and allow it to run for the specified duration to obtain a stable reading.
   4. Record the rheological properties such as viscosity, yield stress, and thixotropy.
   5. Repeat the test as required to obtain consistent and accurate results.
4. Post-Test Activities:
   • Clean the rheometer geometry and sample holder thoroughly after each test.
   • Document the test results in the laboratory logbook and batch record.

4.3 Documentation:

• Record the rheological data, test conditions, and any observations in the laboratory logbook.
• Ensure all documentation is complete and accurate, including the batch number and test date.

4.4 Review and Evaluation:

• Compare the rheological results with the product specifications to determine if the lotion meets the required standards.
• Document any deviations and investigate the cause.

5) Abbreviations, if any

Pa·s: Pascal-second (unit of viscosity)

RPM: Revolutions Per Minute

6) Documents, if any

• Laboratory Logbook
• Batch Record
• Rheometer Calibration Records

7) Reference, if any

• USP <912> Viscosity – Rotational Methods
• Manufacturer’s instructions for the specific rheometer model used

8) SOP Version

Version 1.0