SOP applies to Analytical Method Development (AMD) and Quality Control (QC) teams responsible for developing and executing content uniformity testing in semi-solid dosage forms like ointments, gels, and pastes during product development and routine release.

3. Responsibilities

• Analytical Scientist: Develops and validates the content uniformity method and performs analysis.
• QC Analyst: Prepares samples and standards, executes the method, and maintains data logs.
• QA Executive: Reviews the analytical reports and ensures compliance with regulatory standards.

4. Accountability

The Head of Analytical Method Development is accountable for ensuring the scientific integrity and compliance of content uniformity testing methods for ointments.

5. Procedure

5.1 Sample Selection

1. Randomly select 10 units (e.g., tubes, jars) from a batch as per sampling plan.
2. From each unit, take samples from top, middle, and bottom for better representation.

5.2 Sample Preparation

1. Weigh approximately 1.0 g of ointment into a 50 mL volumetric flask.
2. Add suitable diluent (e.g., methanol or ethanol:water mixture), sonicate for 15 minutes.
3. Cool and make up the volume. Mix thoroughly to ensure complete dissolution.
4. Filter the solution through 0.45 µm membrane filter before injection.

5.3 Standard Preparation

1. Weigh accurately 25 mg of API reference standard into a 50 mL volumetric flask.
2. Dissolve in the same diluent and make up to volume.
3. Filter before use.

5.4 Instrumental Parameters (Example HPLC)

1. Column: C18, 250 mm × 4.6 mm, 5 µm
2. Mobile Phase: 65:35 v/v Methanol:Water with 0.1% acetic acid
3. Flow Rate: 1.0 mL/min
4. Detector: UV at 254 nm
5. Injection Volume: 20 µL

5.5 System Suitability Criteria

1. Five replicate injections of standard solution
2. % RSD of peak area ≤ 2.0%
3. Theoretical plates ≥ 2000, tailing factor ≤ 2.0

5.6 Calculation

Content (%) = (Sample Peak Area / Standard Peak Area) × (Standard Concentration / Sample Weight) × Dilution Factor × 100

5.7 Acceptance Criteria

• Individual content: 90% to 110% of label claim
• Relative Standard Deviation (RSD): Not more than 6.0%

5.8 Method Validation

1. Specificity: Confirmed by placebo interference check
2. Linearity: 50–150% of label claim; correlation coefficient r ≥ 0.999
3. Accuracy: 98.0%–102.0% recovery at 80%, 100%, 120% levels
4. Precision: % RSD of intra- and inter-day results ≤ 2.0%

6. Abbreviations

• API: Active Pharmaceutical Ingredient
• RSD: Relative Standard Deviation
• QA: Quality Assurance
• HPLC: High Performance Liquid Chromatography

7. Documents

1. Content Uniformity Test Log – Annexure-1
2. System Suitability Data – Annexure-2
3. Validation Summary Report – Annexure-3

8. References

• USP <905>: Uniformity of Dosage Units
• ICH Q2(R1): Validation of Analytical Procedures
• EP 2.9.40: Uniformity of Dosage Units

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name	Dr. Anuradha Singh	Rajesh Gokhale	Sunita Reddy
Designation	Analytical Scientist	QA Reviewer	Head – AMD
Department	Analytical Method Development	QA	Analytical Method Development

11. Annexures

Annexure-1: Content Uniformity Test Log

Sample ID	Top	Middle	Bottom	Average (%)	Status
ONT-252-01	98.5%	99.1%	97.8%	98.5%	Pass

Annexure-2: System Suitability Data

Injection	Peak Area	Retention Time	Tailing Factor	Plate Count
1	14325	6.25	1.1	2850

Annexure-3: Validation Summary Report

Content uniformity method for ointment formulation was validated for specificity, linearity (r = 0.9994), precision (% RSD = 1.5%), and recovery (98.2%–101.5%). Method approved for routine QC analysis.

Revision History:

Revision Date	Revision No.	Details	Reason	Approved By
21/05/2025	2.0	Updated sampling approach and added RSD limit	Annual SOP Review	Sunita Reddy
10/02/2022	1.0	Initial SOP Release	New SOP	QA Head