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
4.3.4 Repeat measurements as necessary to ensure consistency and accuracy.
4.4 Interpretation of Results:
4.4.1 Compare measured viscosity values against acceptance criteria specified in pharmacopeial standards or internal specifications.
4.4.2 Document viscosity measurement results accurately, including any deviations from expected values.
4.4.3 Investigate and resolve discrepancies or out-of-specification results promptly.
4.5 Acceptance Criteria:
4.5.1 Semisolid formulations are considered acceptable if their viscosity values fall within predefined limits.
4.5.2 Ensure all viscosity measurements adhere to validated procedures and method validation parameters.
4.6 Documentation:
4.6.1 Record all viscosity testing procedures, results, and observations in the Viscosity Testing Record.
4.6.2 Maintain detailed records of sample details, testing conditions, equipment calibration, and any corrective actions taken.
4.6.3 Review and approve the documentation by QC Manager.
5) Abbreviations, if any
QC: Quality Control
6) Documents, if any
Viscosity Testing Record
Viscometer Calibration Certificates
Sampling Plan Document
7) Reference, if any
USP General Chapter <911> – Viscosity Measurements
Pharmacopeial standards for Viscosity Testing in Semisolids
8) SOP Version
Version 1.0
