Tablets: SOP for In-Process Uniformity of Blend Testing – V 2.0

Standard Operating Procedure for In-Process Uniformity of Blend Testing

Department	Tablet
SOP No.	SOP/TAB/158/2025
Supersedes	SOP/TAB/158/2022
Page No.	Page 1 of 6
Issue Date	01/03/2026
Effective Date	06/03/2026
Review Date	01/03/2027

1. Purpose

To define the procedure for conducting in-process testing of blend uniformity during tablet manufacturing to ensure that the mixture of ingredients is consistent and within the specified quality standards.

2. Scope

This SOP applies to the testing of blend uniformity during the tablet manufacturing process, ensuring uniform distribution of active pharmaceutical ingredients (APIs) and excipients throughout the blend.

3. Responsibilities

Quality Control (QC): Responsible for conducting the blend uniformity test and documenting results. QC will also recommend corrective actions if deviations are observed.
Production Operator: Responsible for ensuring that the blend is prepared as per the batch record and notifying QC when the blend is ready for testing.
Quality Assurance (QA): Ensures that the blend uniformity testing process is compliant with SOP requirements and reviews the results for consistency with product specifications.

4. Accountability

The QC Manager is accountable for ensuring that the blend uniformity testing is conducted regularly during the manufacturing process. The QA Manager ensures the procedure is followed and results are documented appropriately.

5. Procedure

5.1 Preparation for Testing

Verify that the blending equipment has been cleaned and calibrated according to the SOP for equipment qualification.
Ensure that the batch of materials is ready for blending, including proper mixing of active ingredients and excipients.
Prepare the required testing equipment, including sampling tools, scales, and containers for blend sampling.
Confirm that the blend is prepared in accordance with the batch record and formulation requirements.

5.2 Sampling of the Blend

Take a sample of the blend from different points within the blending equipment to ensure that the sample is representative of the entire batch.
Follow the sampling plan for the number of samples to be taken and the locations from which the samples should be collected.
Ensure that the samples are properly labeled with batch information and time of sampling to ensure traceability.

5.3 Blend Uniformity Testing

Weigh each sample of the blend and test for uniformity using a method approved by the QC department (e.g., content uniformity or weight variation test).
For content uniformity testing, check the active ingredient concentration in the sample to ensure it is within the specified range.
If the testing method is weight variation, ensure that each sample meets the predetermined weight variation criteria specified in the batch record.
If an automated system is used for testing, ensure the system is calibrated and functioning properly before testing the samples.

5.4 Documentation of Results

Record the results of the blend uniformity testing in the batch record (Annexure-2), including the test method used, the results for each sample, and any deviations from the specification.
For failed tests, initiate a deviation report (Annexure-1) and document the cause of the failure and any corrective actions taken.
Ensure that the documentation includes relevant details such as sample locations, batch number, test conditions, and any corrective measures taken.

5.5 Corrective Actions for Blend Uniformity Issues

If the blend uniformity test results do not meet the specifications, investigate the cause. Potential causes could include inadequate mixing, equipment malfunction, or incorrect formulation.
Adjust the blending process as needed, including adjusting mixing time, speed, or batch size, and re-sample the blend for further testing.
If the issue persists, consider reworking the batch or investigating other potential causes, such as raw material quality issues.
Ensure that all corrective actions are documented and reviewed by the QA team for approval.

5.6 Acceptance Criteria

The blend is considered acceptable if the test results fall within the established limits for uniformity, as defined in the batch record and specifications.
If more than a specified percentage (e.g., 2%) of the samples fail to meet the uniformity specifications, initiate a full investigation and corrective actions.

5.7 Post-Testing Actions

If the blend is acceptable, proceed with the next step in the tablet manufacturing process, such as tablet compression or coating.
If the blend is rejected, review the blending process, investigate the root cause, and take corrective actions as necessary. Re-sample and retest the blend before proceeding with tablet manufacturing.

6. Abbreviations

SOP: Standard Operating Procedure
GMP: Good Manufacturing Practice
QC: Quality Control
QA: Quality Assurance
CAPA: Corrective and Preventive Action

7. Documents

Batch Record (Annexure-2)
Deviation Report (Annexure-1)

8. References

USP <701> – Uniformity of Dosage Units
21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals (US FDA)
European Pharmacopoeia (EP) – Guidelines for Tablet Manufacturing

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Deviation Report

Deviation Date	Batch Number	Deviation Description	Corrective Action	Responsible Person
15/12/2025	Batch 001	Blend uniformity failed the content uniformity test	Adjusted mixing time and reworked batch	John Doe

Annexure-2: Batch Record

Sample Number	Blend Uniformity Test Result	Moisture Content	Tested By
Sample 1	Pass	3.2%	Jane Smith

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/01/2024	1.0	Initial Version	New SOP Creation	QA Head
01/02/2025	2.0	Updated sampling and testing procedures	Improved uniformity testing accuracy	QA Head