Procedure for Conducting Homogeneity Studies of Ointments

Department	Research and Development (R&D)/Quality Control
SOP No.	FD-015
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 approach for conducting homogeneity studies of ointments. This ensures uniform distribution of active pharmaceutical ingredients (APIs) and excipients throughout the formulation to maintain product consistency and efficacy.

2. Scope

This SOP applies to the Research and Development (R&D) and Quality Control (QC) departments responsible for evaluating the homogeneity of ointments during formulation development and manufacturing. The procedure includes sample preparation, analytical testing, and evaluation criteria.

3. Responsibilities

• Formulation Scientist: Conducts the homogeneity study and records results.
• Quality Control (QC) Analyst: Performs analytical testing to verify uniformity.
• Quality Assurance (QA) Personnel: Ensures compliance with standard procedures.
• R&D Head: Reviews and approves homogeneity study reports before product finalization.

4. Accountability

The R&D and QC Managers are accountable for ensuring that homogeneity studies are conducted per regulatory and quality standards.

5. Procedure

5.1 Sample Collection

• Collect samples from different points of the batch:
  • Top
  • Middle
  • Bottom
• Ensure that at least three replicates are collected from each section.
• Label each sample with batch number, collection point, and date.

5.2 Visual Inspection

• Observe the samples under normal and magnified light.
• Check for uniform color, texture, and phase separation.
• Record any inconsistencies in the Homogeneity Testing Log.

5.3 Chemical Analysis

• Perform assay testing using High-Performance Liquid Chromatography (HPLC) or Ultraviolet (UV) Spectroscopy.
• Measure API concentration in each sample and compare with theoretical values.
• Calculate the percentage variation among different sample locations.
• Ensure the variation is within the acceptable limit (e.g., ±5%).

5.4 Microscopic Examination

• Spread a thin layer of the ointment on a glass slide.
• Examine the uniformity of dispersed API particles under a microscope.
• Document any visible inconsistencies.

5.5 Rheological (Viscosity) Testing

• Measure viscosity at different shear rates using a Brookfield Viscometer.
• Compare results to expected values to confirm consistency.

5.6 Homogeneity Evaluation Criteria

• Acceptable uniformity: API concentration variance within ±5% of label claim.
• No phase separation or particle agglomeration.
• Consistent viscosity readings across different sections.

5.7 Documentation and Reporting

• Record all observations and test results in the Homogeneity Testing Log.
• Summarize findings in the Homogeneity Study Report.
• Obtain approval from the R&D Head and QA before proceeding with further formulation development.

6. Abbreviations

• API – Active Pharmaceutical Ingredient
• QC – Quality Control
• QA – Quality Assurance
• HPLC – High-Performance Liquid Chromatography
• UV – Ultraviolet Spectroscopy

7. Documents

• Homogeneity Testing Log (Annexure-1)
• Homogeneity Study Report (Annexure-2)

8. References

• ICH Q2(R1) Validation of Analytical Procedures
• USP <905> Uniformity of Dosage Units
• 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: Homogeneity Testing Log

Date	Batch Number	Sample Location	Test Parameter	Result	Verified By
01/02/2025	OINT-001	Top	API Assay (%)	99.2%	QA Officer
01/02/2025	OINT-001	Middle	API Assay (%)	98.8%	QA Officer
01/02/2025	OINT-001	Bottom	API Assay (%)	99.0%	QA Officer

Annexure-2: Homogeneity Study Report

Date	Batch Number	Test Parameter	Specification	Result	Final Status
01/02/2025	OINT-001	Viscosity	1000-2000 cP	1500 cP	Pass
02/02/2025	OINT-002	API Uniformity	98-102%	99.0%	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