Zanamivir

Antiviral treatment for influenza A and influenza B has always been a clinical focus in the field of respiratory tract infections. As an anti-influenza virus drug of the neuraminidase inhibitor class, zanamivir specifically inhibits the activity of neuraminidase on the surface of influenza viruses and blocks the release and spread of viruses from infected host cells, thereby shortening the course of the disease and reducing the risk of complications. This drug is clinically mainly used for the treatment of influenza A and influenza B in adults and children over 7 years old, and can also be used for post-exposure prophylaxis of influenza in high-risk groups. Due to its highly conserved target of action, it maintains good antiviral activity against most influenza virus strains, and is an important alternative drug in the influenza prevention and control system.

At present, the global market size of anti-influenza drugs maintains steady growth, among which neuraminidase inhibitor drugs account for more than 40%. As one of the representative varieties of this category, zanamivir is affected by the fluctuation of influenza epidemic cycles, and its market demand has obvious seasonal fluctuation characteristics. In terms of the competitive landscape, the original research product still occupies the main market share, the number of approved generic manufacturers worldwide is small, and there is no approved generic zanamivir preparation launched in China; up to now, there is no publicly verifiable data on the exclusive market size and annual growth rate of zanamivir.

The original research enterprise of zanamivir is GlaxoSmithKline, and the original research trade name is "Relenza". The expiration time of its core compound patent in the United States is 2019, and the Chinese compound patent expired in 2014. The main dosage form approved for the original research is powder for inhalation, with a specification of 5 mg zanamivir per capsule and 20 capsules per box. This original research preparation has been included in the FDA Reference Listed Drug Catalog, and is also included in China's *Catalog of Reference Preparations for Chemical Drugs*. As of September 2025, there is no zanamivir preparation variety approved for marketing in China, and no enterprise has obtained the CDE registration number of zanamivir API. (Data as of September 2025, please refer to the official website of CDE for the latest information)

CATO can provide a full set of impurity reference standards for zanamivir API. Most of the products are in stock. Spot orders paid before 16:00 can be shipped on the same day. All products meet the requirements of multiple national regulations such as the Chinese Pharmacopoeia and FDA, with clear traceability of impurities and complete structural confirmation, which can fully meet the various reference standard needs of enterprises in the stages of API R&D, quality research and declaration.