Standard Operating Procedure for Centrifugation Process for Wet Cake Separation in API Manufacturing

Department	API Manufacturing
SOP No.	SOP/API/027/2025
Supersedes	SOP/API/027/2022
Page No.	Page 1 of 10
Issue Date	13/04/2025
Effective Date	15/04/2025
Review Date	13/04/2026

1. Purpose

To describe the procedure for separating wet cake (solid product) from slurry through centrifugation during API manufacturing, ensuring process consistency, operator safety, and product quality.

2. Scope

This SOP applies to all centrifuge operations used in API manufacturing for solid-liquid separation, including horizontal peeler, top discharge, and bottom discharge centrifuges.

3. Responsibilities

• Production Operator: Operate the centrifuge and perform separation as per BMR.
• Production Supervisor: Supervise the process and ensure parameters are within limits.
• Engineering Department: Maintain centrifuge equipment and perform preventive maintenance.
• QA Department: Review process records and authorize operation startup and completion.

4. Accountability

The Production Manager is accountable for adherence to this SOP and ensuring centrifugation activities comply with GMP and safety protocols.

5. Procedure

5.1 Pre-Operation Check

1. Ensure centrifuge is clean and free from previous product residue.
2. Verify:
   • Filter cloth/paper is intact and secured
   • Drain valves and sight glass are functional
   • Speed control system and emergency brakes are operable
3. Record pre-operation status in “Centrifuge Pre-Check Log” (Annexure-1).

5.2 Charging and Separation

1. Transfer slurry from reactor or receiver into the centrifuge via pump or gravity feed.
2. Set appropriate speed (RPM) as defined in the BMR (typically 500–1500 RPM).
3. Start rotation and observe filtrate clarity from outlet line.
4. Continue until no free liquid is observed.
5. Decant liquid in receiver tank and retain cake inside the centrifuge.

5.3 Washing and Spin Drying

1. Add wash solvent over cake surface and agitate gently (if peeler centrifuge is used).
2. Repeat wash cycles as specified in the BMR (e.g., 2x with chilled IPA).
3. Spin dry the cake at higher RPM (e.g., 1500–2000) for 10–30 minutes.
4. Monitor final filtrate clarity and dryness by checking residual solvent content.

5.4 Discharge of Wet Cake

1. Stop centrifuge and confirm rotor is fully stopped.
2. Open top/bottom cover and discharge the cake into labeled clean container.
3. Record weight and send for drying step.

5.5 Post-Operation Cleaning

1. Flush equipment with water or solvent.
2. Remove filter media for washing or replacement.
3. Wipe outer and inner surfaces with lint-free cloth.
4. Record cleaning status in “Centrifuge Cleaning Log.”

6. Abbreviations

• SOP: Standard Operating Procedure
• BMR: Batch Manufacturing Record
• RPM: Revolutions Per Minute
• QA: Quality Assurance
• GMP: Good Manufacturing Practice

7. Documents

1. Centrifuge Pre-Check Log (Annexure-1)
2. Centrifuge Operation Logbook (Annexure-2)
3. Wet Cake Transfer Record (Annexure-3)

8. References

• ICH Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• 21 CFR Part 211.67 – Equipment Cleaning and Maintenance
• GMP Guidelines for API Plants – WHO Technical Report Series

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Centrifuge Pre-Check Log

Date	Equipment ID	Filter Status	Drain System	Checked By
13/04/2025	CF-101	OK	Operational

Annexure-2: Centrifuge Operation Logbook

Batch No.	Start Time	RPM	Wash Cycles	Drying Time	Operator
API-202504	09:30	1200	2x IPA	20 min

Annexure-3: Wet Cake Transfer Record

Date	Batch No.	Container ID	Weight (kg)	Transferred To	Checked By
13/04/2025	API-202504	CT-27	22.3	Tray Dryer

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/01/2022	1.0	Initial SOP Issue	New SOP	QA Head
13/04/2025	2.0	Added Spin Drying Parameters	Process Optimization	QA Head