Standard Operating Procedure for Isolation by Filtration in API Manufacturing

Department	API Manufacturing
SOP No.	SOP/API/026/2025
Supersedes	SOP/API/026/2022
Page No.	Page 1 of 10
Issue Date	13/04/2025
Effective Date	15/04/2025
Review Date	13/04/2026

1. Purpose

To establish a standard procedure for the isolation of solid active pharmaceutical ingredients (APIs) or intermediates from liquid mixtures using filtration techniques, ensuring maximum yield, safety, and compliance with GMP.

2. Scope

This SOP applies to all batch processes requiring solid-liquid separation via filtration in the API manufacturing facility, including use of Nutsche filter, vacuum filter, or sparkler filter units.

3. Responsibilities

• Production Operator: Perform filtration operations as per BMR instructions.
• Shift Supervisor: Ensure filtration equipment readiness and supervise operations.
• Engineering Department: Maintain and calibrate filtration units.
• QA Department: Review records and ensure adherence to SOP.

4. Accountability

The Production Manager and QA Manager are accountable for proper execution and compliance with filtration protocols.

5. Procedure

5.1 Equipment and Pre-Check

1. Identify type of filtration equipment to be used (Nutsche, vacuum, sparkler).
2. Ensure:
   • Cleanliness of filter vessel and internals
   • Filter cloth or paper is intact and properly installed
   • Gaskets and seals are leak-proof
   • Valves and pressure gauges are calibrated
3. Record pre-operation checklist in “Filtration Equipment Inspection Log” (Annexure-1).

5.2 Filtration Process

1. Transfer slurry or reaction mass to filtration vessel under gravity or pump transfer.
2. Initiate filtration by:
   • Applying vacuum (for vacuum filter)
   • Using nitrogen blanketing or positive pressure (for Nutsche)
3. Observe filtrate clarity at intervals. Continue until liquid passes clear.
4. Record filtration start/end time and filter bed thickness.

5.3 Washing of Cake

1. As per BMR, wash the solid mass with specified solvent.
2. Add solvent to the vessel, agitate if required, and filter again.
3. Repeat washing as per specified number of cycles or until filtrate meets quality parameters.

5.4 Discharge of Wet Cake

1. Once filtration is complete, depressurize system (if pressurized).
2. Open discharge valve and collect wet cake in labeled container or tray.
3. Ensure complete transfer and minimal hold-up inside the vessel.
4. Record quantity and send for drying or further processing.

5.5 Cleaning Post Operation

1. Flush equipment with water or suitable solvent.
2. Remove filter cloth for cleaning or replacement.
3. Record cleaning status in “Equipment Cleaning Log.”

6. Abbreviations

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

7. Documents

1. Filtration Equipment Inspection Log (Annexure-1)
2. Filtration Process Logbook (Annexure-2)
3. Wet Cake Collection Record (Annexure-3)

8. References

• ICH Q7 – Good Manufacturing Practice for Active Pharmaceutical Ingredients
• 21 CFR Part 211.67 – Equipment Cleaning and Maintenance
• EU GMP Annex 1 – Manufacture of Sterile Medicinal Products (if applicable)

9. SOP Version

Version: 2.0

10. Approval Section

	Prepared By	Checked By	Approved By
Signature
Date
Name
Designation
Department

11. Annexures

Annexure-1: Filtration Equipment Inspection Log

Date	Equipment ID	Filter Type	Checked By	Status	Remarks
13/04/2025	NF-01	Nutsche		Clean	Ready for Use

Annexure-2: Filtration Process Logbook

Batch No.	Start Time	End Time	Filtrate Clarity	Washed?	Operator
API-202504	10:00	12:15	Clear	Yes (2x IPA)

Annexure-3: Wet Cake Collection Record

Date	Batch No.	Container ID	Weight (kg)	Transferred To	Checked By
13/04/2025	API-202504	CT-22	18.5	Dryer-01

Revision History:

Revision Date	Revision No.	Revision Details	Reason for Revision	Approved By
01/01/2022	1.0	Initial Release	New SOP	QA Head
13/04/2025	2.0	Added Wet Cake Handling and Sparkler Usage	Process Enhancement	QA Head