Procedure for Testing Ointment Viscosity
| Department | Quality Control (QC)/Quality Assurance (QA)/Production |
|---|---|
| SOP No. | SOP/Ointment/061 |
| Supersedes | V 1.0 |
| Page No. | Page X of Y |
| Issue Date | [Insert Issue Date] |
| Effective Date | [Insert Effective Date] |
| Review Date | [Insert Review Date] |
1. Purpose
The purpose of this Standard Operating Procedure (SOP) is to establish a standardized method for testing the viscosity of ointments. Viscosity is a critical parameter that determines the ease of application, spreadability, and stability of the formulation.
2. Scope
This SOP applies to all personnel in the Quality Control (QC) and Quality Assurance (QA) departments responsible for testing the viscosity of ointments during formulation development, in-process control, and final batch release.
3. Responsibilities
- Quality Control Analyst: Conducts viscosity testing and records results.
- Quality Assurance Personnel: Reviews and approves test results.
- Production Supervisor: Ensures that the ointment batches conform to viscosity requirements.
- R&D Team (if applicable): Evaluates formulation modifications based on viscosity test results.
4. Accountability
The QC and QA Managers are accountable for ensuring that viscosity tests are conducted accurately and documented as per regulatory and GMP standards.
5. Procedure
5.1 Equipment and Materials
- Brookfield Viscometer (or equivalent)
- Spindle set (as per formulation requirements)
- Calibrated thermometer
- Standardized viscosity reference material
- Calibrated weighing balance
- Clean sample containers
- Data recording sheets
5.2 Pre-Test Preparations
- Ensure the viscometer is calibrated before use.
- Ensure the sample is free from air bubbles and is at
room temperature (25°C ± 2°C) unless otherwise specified.
Stir the ointment sample gently to ensure uniformity before testing.
Select the appropriate spindle (e.g., Spindle No. 6 for semi-solid formulations).
5.3 Viscosity Measurement
5.3.1 Brookfield Viscometer Method
- Turn on the viscometer and select the appropriate speed (e.g., 10, 20, or 50 rpm).
- Lower the spindle into the sample ensuring proper immersion as per instrument guidelines.
- Allow the viscometer to stabilize for at least 30 seconds.
- Record the viscosity reading in centipoise (cP) or milliPascal-seconds (mPa·s).
- Repeat the test three times and take the average of the readings.
5.3.2 Cone and Plate Viscometer Method (If Applicable)
- Ensure the sample is evenly spread across the plate.
- Set the appropriate temperature control (if applicable).
- Start the test and record the viscosity readings as per instrument guidelines.
5.4 Acceptance Criteria
- The viscosity should be within the predefined range for the specific ointment formulation.
- Significant deviations from the standard range may indicate formulation issues requiring further evaluation.
5.5 Documentation
- Record all viscosity measurements, spindle numbers, and speeds in the Viscosity Test Log.
- Document observations such as sample homogeneity and instrument stability.
- QA personnel must review and approve results before batch release.
6. Abbreviations
- GMP – Good Manufacturing Practices
- QA – Quality Assurance
- QC – Quality Control
- cP – Centipoise
- mPa·s – MilliPascal-seconds
7. Documents
- Viscosity Test Log (Annexure-1)
- Ointment Batch Testing Report (Annexure-2)
8. References
- WHO GMP Guidelines for Pharmaceutical Manufacturing
- USP <912> – Viscosity Determination
- ICH Q2 (R1) – Validation of Analytical Procedures
9. SOP Version
Version 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: Viscosity Test Log
| Date | Batch Number | Spindle Used | Speed (RPM) | Viscosity (cP) | Result | Verified By |
|---|---|---|---|---|---|---|
| 01/02/2025 | OINT-101 | No. 6 | 20 | 45,000 | Pass | QA Officer |
| 02/02/2025 | OINT-102 | No. 6 | 20 | 47,500 | Pass | QA Officer |
Annexure-2: Ointment Batch Testing Report
| Date | Batch Number | Test Method | Acceptance Criteria | Result | Final Status | Approved By |
|---|---|---|---|---|---|---|
| 01/02/2025 | OINT-101 | Brookfield | 40,000 – 50,000 cP | 45,000 cP | Approved | QA Head |
| 02/02/2025 | OINT-102 | Brookfield | 40,000 – 50,000 cP | 47,500 cP | Approved | QA Head |
12. Revision History:
| Revision Date | Revision No. | Details of Revision | Reason for Revision | Approved By |
|---|---|---|---|---|
| 01/01/2024 | 1.0 | Initial Version | New SOP | QA Head |
| 01/02/2025 | 2.0 | Updated SOP Format | Standardization of Document | QA Head |