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Company Information

Message from the President

Yuzo Tarumi, Ph.D.


In the half century since our founding in 1959, Koken has grown to become a world-class specialist in the development and manufacture of silicone materials to replace human skin and other parts of the body, along with various types of medical plastics, educational medical models for medical education, and Atelocollagen products ranging from cosmetics to medical-use materials. Our successes in each area continue to provide the foundations for new endeavors as we continue to build and expand upon our core medical technologies. Throughout this development, we remain true to our starting-point concept of originality in product design and development with the aim of finding ways to improve and enrich the quality of life of the people who make use of our products in the course of medical treatment. In the interlocking fields of medical treatment, good health and the quality of life, Koken presents the essential products, service and technology.

Our corporate mission is best represented by our dual objectives of compliance and innovation, which comprise the foundation of all our business activities. While compliance with laws and observing social norms is natural behavior in the course of doing business, we do believe it imperative that we fully meet the expectations of society and further push the horizon in new possibilities, and continue to expand the boundaries of innovation.

Koken now stands at the beginning of a new era in the history of our corporation. Our Atelocollagen finds use in a broad range of products, from medical equipment to a base material for cosmetic products, all of which have contributed to a higher quality of life for millions. And, new applications for Atelocollagen are being discovered at an increasing pace thanks to our original R & D in new fields. The application of collagen to new fields of medical treatment, such as Atelocollagen-based nucleic acid drug delivery systems, represents the realization of leading-edge technology in truly original products that provide gentle yet effective medical treatment to people around the world. Koken intends to continue this stance in product development while also meeting the needs of people while creating products that reflect new values as we pursue our business vision on a global level.



Company Name KOKEN CO., LTD
Established October 1959
President Yuzo Tarumi , Ph.D.
Employees 249 ( as of  March 2011 )
Main products Medical plastics
Medical-use collagen products
Skin-care products, cosmetic basic materials
Medical & educational equipment, including educational medical models
Headquarters 1-4-14 Koraku, Bunkyo-ku, Tokyo 112-0004, Japan
Phone:81-3-3816-3562 Fax:81-3-3816-3582

The Research Center

The Research Center Photo

On the forefront of new technological development

Koken has enjoyed a long track record of success in the research and development of Atelocollagen, and is widely recognized as the world leader.  This R&D takes place at the Research Center, where new applications for Atelocollagen for medical use and as a cosmetic ingredient are always being developed into new products through advanced research.
The Research Center represents the foundation for Koken’s technical prowess, and continues to draw attention from manufacturers, academia and government, which lead to many joint development projects. Here is where Koken’s many successes originate.

The Research Center Photo

Progress continues in collagen application development for leading-edge medical treatment, such as nucleic acid medicines.

In its efforts toward new developments for Atelocollagen, Koken is highly committed to original research and technical development.  One example, which is now drawing great attention, is the field of leading-edge medical treatment, represented by nucleic acid medicines.
Koken has successfully discovered that nucleic acid effectively functions and expresses on an intracellular level when compound with Atelocollagen as the incorporating structure.
This new technology shows great promise for applying gene therapy in the treatment of human disease, such as cancer. In addition, experimental functional analysis on genes shows promise for wide applications, thus expanding the functional possibilities of Atelocollagen.
The high biocompatibility of Atelocollagen makes it ideal for intracellular transport of medicines, with high expectations future applications. Moreover, in the advancing field of biomedical tissue engineering of artificial organs or regenerative medicine, materials with Atelocollagen are expected to play an important role in a variety of applications. We have initiated research using pluripotent stem cells such as ES, iPS cells.


The Manufacturing Facilities

Tsuruoka Factory, Yamagata Prefecture Photo

A manufacturing facility directly linked to research and development.

Koken’s advanced manufacturing and quality control organizations are located at Tsuruoka Plant, Tsuruoka East Plant, and Sakata Plant in Yamagata Prefecture, and all operations from ordering to delivery are entirely under computer control.
The manufacture of medical plastics and collagen is automated, while the production of educational medical models at Tsuruoka East Plant is performed entirely by hand in order to assure the highest possible quality. Customers can use actual educational medical models at the Educational Medical Model Training Center.
In addition to these two facilities, a new facility, and Sakata Plant, specializes in processing freeze-dried cosmetics. Thus, our manufacturing facilitires are directly linked to the R&D division to ensure the timely creation of products that adequately meet customer needs.

  • Mixing tank Photo
  • Vacuum multi-stirring machine Photo

The TÜV Mark - a certification of trust, safety and quality

TUV mark

Development, Production and Distribution of
Collagen Products for Medical Use with and without
Pharmaceuticals, Tracheal Tube Products, and Nostril Retainer



TUV mark

Development, Production and Distribution of
Educational Medical Models, Cosmetics and
Cosmetic Raw Materials