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About us

With the technology cultivated through pharmaceutical manufacturing over many years, we respond to needs for various types of contract manufacturing services in a one-stop manner.

Iwaki Seiyaku Sakura Factory

As the main plant of Astena holdings, Iwaki Seiyaku Sakura Factory, Co., Ltd. is engaged in various contract manufacturing services related to pharmaceuticals, from investigational agent manufacturing to commercial production.

With equipment, technology, and know-how to manufacture pharmaceuticals in a wide range of dosage forms, and by utilizing the value chains of each Iwaki Group company, we have established a system that allows us to contract services from development to production in a one-stop manner.

Fully equipped facilities capable of manufacturing various dosage forms

Fully equipped facilities capable

Iwaki Seiyaku Sakura Factory has facilities capable of manufacturing pharmaceuticals in a wide range of dosage forms, including solid preparations and injections, semi-solid preparations such as ointments and creams. Especially for external preparations, we have facilities capable of producing 200 tons or more per year. We plan to build a system to increase the production capacity to 300 tons in the future through further capital investment and other measures.

In addition, we have an environment with advanced facilities that allows us to contract various types of testing, such as quality testing of materials, and sterility and animal testing of drugs, which are listed in the Japanese Pharmacopoeia.

We satisfy the requests of many customers based on the manufacturing results of various pharmaceuticals, from investigational agent manufacturing to commercial production.

Realization of a one-stop service by utilizing group power

Realization of a one-stop service by utilizing group power

With the operation of Iwaki Seiyaku Sakura Factory, the Iwaki Group has established a contract system from development to production in a comprehensive way.

We complete, in one stop, a wide range of drug life cycles from prescription design in the development stage, investigational agent manufacturing and scale-up, leading to commercial production, by collaborating with group companies and business partners. In addition, with respect to the manufacture of active pharmaceutical ingredients and external procurement of APIs and raw materials, which are necessary for pharmaceutical manufacturing, we can make meaningful proposals for costs by collaborating with group companies.


Iwaki Seiyaku Sakura Factory will work on the development of the entire group, aiming to become a company that can continue to contribute to society, for example, by planning aggressive capital investment and personnel recruitment also in the future.


Business Summary

Iwaki Seiyaku Sakura Factory is a contract manufacturer of pharmaceuticals that can meet a variety of needs, from prescription examination, investigational agent manufacturing and commercial production, to quality testing services.

As a plant of an original drug manufacturer, we have been involved in the manufacture of various dosage forms, such as solid preparations, external preparations, granules, liquid medications, and injections, for many years. In July 2020, we became a member company of the Iwaki Group and took a new step as a CMO plant. By combining our efforts in manufacturing and quality control cultivated over many years, with the Iwaki Group’s raw material procurement and supply capabilities and formulation technology, we aim to be a contract manufacturer that can satisfy all requirements, including low prices, high quality, and stable supplies.

Prescription examination

Prescription examination

We can provide support services to meet customer needs, from formulation design, including formulation development and examination of the manufacturing method, to prescription examination, including changes in dosage forms, improvements in usability, and miniaturization of tablets. We also provide services for the acquisition of various types of data, and stability testing, compatibility testing, etc.

Manufacturing of investigational agents

Manufacturing of investigational agents

Utilizing the experience and know-how in investigational agent manufacturing that have been cultivated over many years, we provide services for the manufacture of investigational agents in various dosage forms in a timely manner.

Manufacturing of pharmaceuticals

Manufacturing of pharmaceuticals

From small-lot products to large-scale products, our experienced technical staff transfer technology efficiently and reliably, and work quickly until commercial production starts.

Quality testing

Quality testing

We can also provide services for sterility testing using sterility test isolators, etc., and various physical and chemical testing.

Company Profile

Established April 2020
Capital 100 Million JPY
Major Shareholders SPERA PHARMA, Inc. (100%)
Head Office 2183-1 Teranosaku, Ota, Sakura-shi, Chiba Prefecture, Japan
Phone number +81-43-485-7111
Employees 169
Chairman Keitaro Iwaki
CEO Takashi Hirose
Plant Manager Tsuyoshi Ishizuka
Director Makoto Fukuta
Auditor Toshimitsu Isobe
Major Products Ethical drugs, allergen preparations and test agents
Membership Japan CMO Association
Chiba Pharmaceutical Manufacturers Association
Pharmaceutical Manufacturers Association of Tokyo


Please feel free to contact us regarding contract
manufacturing of pharmaceutical products.