Cartridge filter -Integrity testing of SOP on

Cartridge filter -Integrity Testing SOP

Objective: To lay down a procedure for integrity testing of the cartridge filter.

Scope: This SOP is applicable for integrity testing of cartridge filters in the formulation plant.

Responsibility: Production officer / Executive

Accountability: The production Head shall be accountable for compliance with SOP.



Close the air vent of the filter housing.

Check the tightness of the clamp. It should not be loose at the connections.

Ensure that compressed air is available at a pressure of 4 to 6 kg/cm2.


Wet the cartridge filter with Water for Injection (WFI) or Isopropyl alcohol (use Water for injection for the hydrophilic filter and 70% Iso Propyl Alcohol (IPA) for the hydrophobic filter) through the filter housing.

Open the air vent of the filter housing so that air is removed from the vent and close the air vent when water for injection or the Iso Propyl Alcohol droplet starts oozing out.

Connect the filter housing inlet to the outlet of integrity testing instruments.

Connect the compressed air supply to the inlet of the integrity testing instrument.

Open the valve of the compressed air supply line and adjust the air pressure between 4-6 kg/cm² for the integrity testing instruments.

Connect the power supply of the instrument and switch ON the instrument.

Integrity testing instruments is itself start the self-test program.

During this test, instruments check the correct functioning of EPROM, internal communication, inlet pressure, pressure transducers, valves, and regulators are checked. An internal leak test is also carried out.

After completion of self test, the instrument displays the main menu. Press the “Bubble Point” then after the screen displays the bubble point test.

Enter the PIN and Password then press OK. The screen displays the Bubble Point Test program. Select the test program and press OK.

Check the test program and enter the details as given below:-

Hydrophobic Filter

Compressed air line Filter Vial washing Machine 1320 mbar
Compressed Air Line Filter Garment washing Area 1100 mbar
Compressed Air Line Filter Equipment Wash Area 1100 mbar
Compressed Air Line Filter Bung Processor Cum steam sterilizer 1100 mbar
Compressed Air Line Filter Cooling Zone 1100 mbar
Vacuum Break Filter Bung Processor cum steam sterilizer sterile side (Cooling Zone) 1100 mbar
Compressed Air Line Filter Vial Filling Machine 1320 mbar
Compressed Nitrogen Line Filter Vial Filling Machine 1320 mbar
Compressed Air Line Filter Vial Filling Machine(Pneumatic Operation) 1320 mbar
Compressed Nitrogen Line Filter Vial Filling Machine (Process Operation) 1320 mbar
Vacuum Line Filter Vial Filling Machine 1320 mbar
Carbon dioxide line filter Vial Filling Machine 1100 mbar

Hydrophilic Filter

Disinfectant solution, water for injection, and IPA Cooling Zone 3450 mbar


Press the start to run the machine. In the bubble point test, pressure develops up to 700 mbar (10 PSI) then the instrument checks the pressure leak in the filter.

During the measurement phase of the test, pressure increases, and simultaneously instruments measure the pressure decay.

When the developed pressure attains the specified minimum bubble point line then the test result displays “BP within limit” and if the developed pressure does not attain the specified bubble point line then the test result displays “ BP outside limit” so the filter is defective.

If the filter fails in integrity on retesting, then reject the filter replace it with a new filter, and check its integrity.

Shut Down

Disconnect the integrity testing apparatus from the filter housing.

In case a sterilizing grade filter which is used for filtration of Nitrogen and compressed Air, carbon dioxide in the Vial Filling Room, fails in the integrity test (post), inform the Production Manager and Quality Assurance (Q.A.) Manager. The Production Manager is to initiate an investigation in consultation with the Q.A. Manager for the failure. The decision for the release or disposition of the batch is to be taken by the Q.A. department.

Record the integrity testing of cartridge filter details.


Every 15 days for airline cartridge filter/after dissembling of the filter from the line.

Before and after sterilization of cartridge filter.

Before and after filtration of Water for Injection / Disinfectant solution/IPA.

List of Annexure

Integrity Testing of Cartridge Filter Record

About Pharmaceutical Guidanace

Ms. Abha Maurya is the Author and founder of pharmaceutical guidance, he is a pharmaceutical Professional from India having more than 18 years of rich experience in pharmaceutical field. During his career, he work in quality assurance department with multinational company’s i.e Zydus Cadila Ltd, Unichem Laboratories Ltd, Indoco remedies Ltd, Panacea Biotec Ltd, Nectar life Science Ltd. During his experience, he face may regulatory Audit i.e. USFDA, MHRA, ANVISA, MCC, TGA, EU –GMP, WHO –Geneva, ISO 9001-2008 and many ROW Regularities Audit i.e.Uganda,Kenya, Tanzania, Zimbabwe. He is currently leading a regulatory pharmaceutical company as a head Quality. You can join him by Email, Facebook, Google+, Twitter and YouTube

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