Asahi Kasei Medical Co., Ltd.

Naoko Hamasaki

Shoichi Ide

Tomoko Hongo

Fumihiko Yamaguchi

Mitsunori Kubozaki

The present invention provides a method of testing the integrity of a microporous membrane using a colloid solution containing metal particles or metal compound particles that can accurately determine the integrity of a virus removal membrane formed of hydrophilized synthetic polymer that has been subjected to protein solution filtration, and to provide a method of producing the colloid solution. The colloid solution comprises a solvent and metal particles dispersed in the solvent, and the solvent comprises components (A) and (B), (A) and (C), or (A), (B), and (C), wherein the component (A) is an anionic polymer having a sulfonic acid group, the component (B) is at least one nonionic surfactant selected from the group consisting of a nonionic surfactant having a polycyclic structure in a hydrophobic moiety and a polyoxyethylene sorbitan fatty acid ester, and the component (C) is a water-soluble polymer having a pyrrolidone group.

Method of testing integrity of microporous membrane

A colloid solution that exhibits storage stability and pH stability, being useful as viral substitute particles for use in an integrity test for virus removal membrane. In particular, a metal colloid solution characterized in that it comprises metal particles or metal compound particles of 1 to 100 nm average diameter, a water soluble high-molecular-weight dispersant having an N group and water and/or a water soluble organic solvent, the metal colloid solution being stable for a prolonged period of time and being stable in at least pH values ranging from 4 to 11.

Growing community of inventors

Tokyo, Japan

Naoko Hamasaki