Standard Operating Procedure for Assay Testing of Capsule Fill Materials

Department	Capsule Manufacturing
SOP No.	SOP/CM/184/2025
Supersedes	SOP/CM/184/2022
Page No.	Page 1 of 8
Issue Date	01/02/2025
Effective Date	05/02/2025
Review Date	01/02/2026

1. Purpose

To outline the procedure for performing assay testing on capsule fill materials to ensure that the active pharmaceutical ingredient (API) content meets the required specifications.

2. Scope

This SOP applies to the assay testing of all capsule fill materials to confirm the concentration of the active pharmaceutical ingredient (API) and ensure compliance with batch release specifications.

3. Responsibilities

• Quality Control (QC) Team: Responsible for performing assay testing, analyzing results, and documenting findings.
• Quality Assurance (QA) Team: Ensures the assay testing process complies with regulatory requirements and approves results.
• Production Team: Provides capsule fill material samples for assay testing at specified intervals.

4. Accountability

The QA Manager is accountable for ensuring that assay testing is performed according to regulatory standards. The QC Supervisor oversees testing execution and documentation. The Production Supervisor ensures timely sample submission.

5. Procedure

5.1 Pre-Testing Setup

Before starting the assay test, ensure the following:

1. Review Test Specifications
   1. Verify assay specifications for the active pharmaceutical ingredient (API) in the capsule fill material, ensuring compliance with approved limits.
2. Prepare Equipment
   1. Ensure that all laboratory equipment, such as HPLC systems or UV spectrometers, is calibrated and operational. Document calibration in the Equipment Calibration Log (Annexure 1).
3. Prepare Sample
   1. Obtain a representative sample of capsule fill material according to the sampling plan (typically 10-20 capsules). Ensure proper handling to prevent contamination.

5.2 Assay Testing Procedure

Follow these steps to perform the assay test:

1. Extract API from Capsules
   1. Open each capsule and remove the fill material. Accurately weigh the fill material using a calibrated balance. Record the weight in the Assay Testing Log (Annexure 2).
2. Prepare Sample Solution
   1. Weigh an appropriate quantity of the fill material, dissolve it in a suitable solvent (e.g., methanol, water), and filter the solution if necessary.
3. Perform Assay Analysis
   1. Analyze the sample solution using the appropriate analytical technique (e.g., HPLC, UV spectrophotometry) to determine the concentration of the API.
4. Calculate API Content
   1. Calculate the API content in the capsule fill material as a percentage of the label claim. Compare the result with the defined acceptance limits (typically ±10% of the label claim).
5. Document Results
   1. Record all assay results in the Assay Testing Log (Annexure 2), including the sample details, test method used, and any deviations.

5.3 Post-Testing Activities

Once the assay testing is complete, ensure the following actions are taken:

1. Review Test Results
   1. The QA Manager reviews the test results and ensures compliance with the specifications. If the assay fails, initiate an investigation and determine the cause.
2. Corrective Actions
   1. If the assay fails, investigate the cause (e.g., formulation error, equipment malfunction) and take corrective actions. Retest the sample if necessary.
3. Training and Feedback
   1. If errors are identified in the testing process, provide feedback and additional training to the QC personnel.
4. Record Keeping
   1. Ensure all assay testing records are properly filed and archived in accordance with regulatory retention requirements.

6. Abbreviations

• SOP: Standard Operating Procedure
• GMP: Good Manufacturing Practice
• QA: Quality Assurance
• QC: Quality Control
• API: Active Pharmaceutical Ingredient
• HPLC: High-Performance Liquid Chromatography
• UV: Ultraviolet

7. Documents

1. Annexure 1: Equipment Calibration Log
2. Annexure 2: Assay Testing Log
3. Annexure 3: Deviation Report

8. References

• FDA Guidance on Assay Testing for Pharmaceutical Products
• Good Manufacturing Practice (GMP) Guidelines
• USP <711> – Dissolution Testing
• ICH Q6A – Specifications: Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure 1: Equipment Calibration Log

Equipment ID	Calibration Date	Operator	Calibration Details	Next Calibration Due
HPLC 108	01/02/2025	John Doe	Calibration of detector and column	01/02/2026

Annexure 2: Assay Testing Log

Capsule ID	API Content (mg)	Label Claim (mg)	Deviation (%)	Remarks
Capsule 001	500	500	0%	Pass

Annexure 3: Deviation Report

Batch ID	Deviation Type	Corrective Action	Responsible Person	Completion Date
Batch 001	API Deviation	Reformulation	Production Supervisor	03/02/2025

12. Revision History

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/01/2024	1.0	Initial version of SOP	Creation of SOP for assay testing of capsule fill material	QA Head
01/02/2025	2.0	Updated testing methods and documentation	Improvement of test methods and compliance	QA Head