About Us

Toref is an impurity brand of Guangzhou Tosun Pharmaceutical Limited, which is a global manufacturer and supplier of high-quality Impurity Standards for the Pharmaceutical industry. We are specialized in providing Pharmaceutical Impurity Standards, including pharmacopeical and non-pharmacopeial. We leverage our wide spectrum of business in the fields of research, manufacturing, and supply to help our customers make best-informed decisions tailored to their evolving needs for high-quality impurity standards.Thus Toref has earned reputations as one of the most reliable manufacturer and supplier of Pharmaceutical Impurity Standards.

Toref currently offers an extensive catalogue in excess of 10,000 products with an extensive inventory for immediate shipment. Where stock is unavailable, Toref will undertake production of new and known compounds upon customer order. Toref provides flexible, efficient and cost effective solutions of carrying out short or long term projects. We not only want to provide you excellent products and service but also aim to work closely and collaborate with you so that we understand your needs to provide a clear timeline and direction for your every project.
  • Established in 1999 and headquartered in Guangzhou, China.
  • One of the top provider of Pharmaceutical Impurity Standards.
  • Offering custom synthesis of the products which are new or not in our stock.
  • Providing products with CoA and H-NMR, MS, HPLC purity. On request, we also provide UV, IR, C-NMR and more.

Misson, Vision & Value of Toref


Our Mission

Providing exceptional Pharmaceutical Impurity Standards and Services are the Mission of our company. We continually strive to exceed all expectations delivering every order with passion and operational excellency.


Our Vision

Toref intends to be the recognized leader in the worldwide for supply of Impurities (pharmacopeial & non-pharmacopeial) and Services and consumables of products to Pharmaceutical & Health Industry.


Our Value

Highest Quality & Integrity - we conduct our business with passion, profession and integrity.
Excellence - we constantly strive to be better at what we already do well.
Win-Win - we collaborate in order to succeed.

Why Choose Us

In addition to having a huge product library and excellent service, we also pay attention to the internal development of the company and staff. The phenomenal business growth seen by Toref in the recent past has been fuelled by the staff we have, by the free and nurturing work environment we provide, and by the support given through clear people processes. We have always firmly believed that its strength lies within the talent it attracts and retains. Whether it is through robust performance management systems, formal learning and development processes, or career planning processes, the attempt is always to develop individuals who can build an aggressive, growth-oriented environment.

Our Clients

We are pleased to be able to work with some of the world’s most innovative and successful companies. Their support makes us be able to deliver our programs globally, and at scale.