Procedure for Viscosity Testing in Semisolids

1) Purpose

The purpose of this SOP is to outline the procedure for measuring the viscosity of semisolid pharmaceutical formulations to ensure consistency and quality.

2) Scope

This SOP applies to all semisolid formulations (e.g., creams, ointments, gels) manufactured within the facility that require viscosity testing as part of quality control.

3) Responsibilities

Quality Control (QC) Department: Responsible for conducting viscosity testing and ensuring compliance with this SOP.
Production Department: Responsible for providing semisolid samples and supporting QC during testing.

4) Procedure

4.1 Equipment Preparation:
    4.1.1 Verify and calibrate the viscosity measuring instrument (e.g., viscometer) according to manufacturer’s instructions.
    4.1.2 Ensure adequate supply of viscosity standards (if applicable) and cleaning solutions.
    4.1.3 Perform instrument suitability checks using standard viscosity fluids before testing.

4.2 Sample Preparation:
    4.2.1 Obtain representative samples of semisolid formulations from different batches.
    4.2.2 Allow samples to equilibrate to room temperature if necessary.
    4.2.3 Mix samples thoroughly to ensure homogeneity before viscosity measurement.

4.3 Viscosity Measurement:
    4.3.1 Set the appropriate parameters (e.g., spindle speed, temperature) on the viscometer based on sample characteristics.
    4.3.2 Immerse the viscometer spindle into the sample without introducing air bubbles.
    4.3.3 Allow the spindle to stabilize and record the viscosity reading displayed on