Pharma Focus Asia

Integrity testing of Planova™ BioEX virus removal filters used in the manufacture of biological products

Shinya Sekinea, Masayasu Komurob, Takayuki Sohkac, Terry Satoc


Confirmation of virus filter integrity is crucial for ensuring the safety of biological products. Two main types of virus filter defects may produce inconsistent and undesirable performance in virus removal: improper pore-size distribution across the membrane; and specific damage, such as tears, broken fibers, or pinholes. Two integrity tests are performed on each individual filter manufactured by Asahi Kasei Medical to ensure the absence of these defects prior to shipment. In this study, we verified that typical usage of Planova™ BioEX filters would not improperly shift the pore-size distribution. Damage occurring during shipment and use (e.g., broken fibers or pinholes) can be detected by end-users with sufficient sensitivity using air–water diffusion based leakage tests. We prepared and tested filters with model pinhole defects of various sizes to develop standard acceptance criteria for the leakage test relative to porcine parvovirus infectivity logarithmic reduction values (LRVs). Our results demonstrate that pinhole defects at or below a certain size for each effective filter surface area have no significant impact on the virus LRV. In conclusion the leakage test is sufficiently sensitive to serve as the sole end-user integrity test for Planova™ BioEX filters, facilitating their use in biopharmaceuticals manufacturing.

Author Affiliations:  Bioprocess Technology Development Department, Asahi Kasei Medical MT Corporation, 5-4960 Nakagawara, Nobeoka, Miyazaki 882-0031, Japan

Medical Material Laboratory, Medical Products Development Division, Asahi Kasei Medical Co., Ltd., 5-4960 Nakagawara, Nobeoka, Miyazaki 882-0031, Japan

Technical Marketing Department, Bioprocess Division, Asahi Kasei Medical Co., Ltd., 1-105 Kanda Jinbocho, Chiyoda-ku, Tokyo 101-8101, Japan

Citation: Shinya Sekinea, Masayasu Komurob, Takayuki Sohkac, Terry Satoc Integrity testing of Planova™ BioEX virus removal filters used in the manufacture of biological products 2015 doi :

Received 25 August 2014, Revised 7 February 2015, Accepted 9 February 2015, Available online 7 March 2015


Planova™ BioEX virus filter; Air/water diffusion-based leakage test; Integrity testing; Forward/diffusive flow; Biologicals


BP, bubble point; GPT, gold particle test;IT, integrity test; LRV, logarithmic reduction value; Lv, leak value; PLT, Planova™ Leak Tester; PPV, porcine parvovirus; PVDF, polyvinylidene fluoride; SD, standard deviation; TCID50, 50% tissue culture infectious dose


The authors thank L.P.S. Works Co., Ltd. for their laser processing of pinhole fibers. The authors thank Dr. Marcus Inouye, Dr. Masayasu Takahara, Mr. Tomo Miyabayashi, and Mr. Fujiharu Nagoya for their valuable suggestions, Mr. Nobufumi Kawano, Mr. Kazuya Kobayashi, and Dr. Kouichirou Yanagida for their skillful experimental assistance, Ms. Linda Gudex for assistance in preparing the manuscript, and Dr. Thierry Burnouf for his valuable discussions to improve the final manuscript.

Conflict of interest

All of the authors are employees of Asahi Kasei Medical and its related company.

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