Procedure for Optimizing Ointment Viscosity Parameters

Department	Research and Development (R&D)/Quality Control
SOP No.	FD-016
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 process for optimizing viscosity parameters in ointments. Proper viscosity ensures ease of application, spreadability, and uniform drug delivery, thereby maintaining product efficacy and stability.

2. Scope

This SOP applies to the Research and Development (R&D) and Quality Control (QC) departments responsible for determining, adjusting, and optimizing the viscosity of ointments during formulation development and manufacturing.

3. Responsibilities

• Formulation Scientist: Develops and adjusts viscosity parameters for different ointment formulations.
• Quality Control (QC) Analyst: Conducts viscosity testing and verifies compliance with product specifications.
• Quality Assurance (QA) Personnel: Ensures compliance with standard procedures and regulatory guidelines.
• R&D Head: Reviews and approves viscosity optimization reports before finalizing formulations.

4. Accountability

The R&D and QC Managers are accountable for ensuring that viscosity optimization is conducted as per regulatory and quality standards.

5. Procedure

5.1 Selection of Ointment Formulation Components

• Identify the base components, including oils, waxes, and emulsifiers.
• Select appropriate gelling and thickening agents.
• Ensure that all raw materials comply with pharmacopeial standards (USP, BP, IP).

5.2 Initial Viscosity Assessment

• Prepare an initial batch of ointment based on the proposed formulation.
• Measure viscosity using a Brookfield Viscometer or equivalent equipment.
• Document initial viscosity values in the Viscosity Optimization Log.

5.3 Adjustment of Viscosity Parameters

• If viscosity is too high:
  • Increase the proportion of liquid components (e.g., oils, solvents).
  • Reduce the concentration of thickening agents.
  • Adjust processing parameters such as mixing speed and temperature.
• If viscosity is too low:
  • Increase the concentration of thickening or gelling agents.
  • Reduce the amount of liquid excipients.
  • Modify cooling rates to enhance consistency.

5.4 Rheological Testing

• Measure viscosity at different shear rates to assess shear-thinning or thixotropic behavior.
• Perform oscillatory rheometry to evaluate viscoelastic properties.
• Compare test results with target viscosity specifications.

5.5 Spreadability Testing

• Apply a standard weight to a 1 g sample of ointment placed between two glass slides.
• Measure the diameter of the spread sample.
• Ensure spreadability falls within the acceptable range for topical application.

5.6 Stability Testing

• Store optimized formulations under different conditions:
  • 25°C ± 2°C / 60% RH
  • 40°C ± 2°C / 75% RH
  • Refrigerated conditions (2-8°C)
• Monitor viscosity over time to ensure long-term stability.
• Document any changes in the Stability Testing Report.

5.7 Documentation and Reporting

• Record all viscosity test results in the Viscosity Optimization Log.
• Summarize findings in the Viscosity Optimization Report.
• Obtain approval from the R&D Head and QA before finalizing viscosity parameters.

6. Abbreviations

• QC – Quality Control
• QA – Quality Assurance
• USP – United States Pharmacopeia
• BP – British Pharmacopeia
• IP – Indian Pharmacopeia
• RH – Relative Humidity

7. Documents

• Viscosity Optimization Log (Annexure-1)
• Viscosity Optimization Report (Annexure-2)

8. References

• USP <911> Viscosity Guidelines
• ICH Q1A (R2) Stability Testing Guidelines
• WHO GMP Guidelines for Pharmaceutical Manufacturing
• 21 CFR Part 211 – Current Good Manufacturing Practices

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 Optimization Log

Date	Batch Number	Test Parameter	Specification	Result	Verified By
01/02/2025	OINT-001	Viscosity (cP)	1000-2000	1500	QA Officer
02/02/2025	OINT-002	Spreadability (mm)	5-10	7	QA Officer

Annexure-2: Viscosity Optimization Report

Date	Batch Number	Parameter Adjusted	Adjustment Method	Final Viscosity (cP)	Final Status
01/02/2025	OINT-001	Thickening Agent	Increased concentration	1800	Pass
02/02/2025	OINT-002	Oil Content	Reduced quantity	1200	Pass

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