Esketamine

As an important clinical drug in the fields of pain treatment and mental disorders, esketamine is a non-competitive antagonist of the N-methyl-D-aspartic acid (NMDA) receptor and the S-enantiomer of ketamine. Its anesthetic potency is twice that of racemic ketamine, with faster recovery and milder psychiatric-related adverse reactions. In clinical practice, in addition to being used for induction and maintenance of surgical anesthesia and analgesia for invasive procedures, its nasal spray formulation has also been approved for the treatment of patients with treatment-resistant depression and major depressive disorder with suicidal ideation, filling the clinical gap that traditional antidepressants have slow onset and limited effect in emergency intervention. The applicable population covers two categories: surgical patients requiring anesthesia and depression patients who do not respond to conventional treatment.

The global market size of esketamine has maintained steady growth in recent years, exceeding USD 900 million in 2023, with a compound annual growth rate of approximately 18%. The Chinese market is in a stage of rapid expansion. In 2023, the terminal sales in public medical institutions exceeded RMB 1.2 billion, of which medication in the anesthesia field accounted for approximately 72%, and the proportion of medication in the mental health field is increasing year by year. At present, the domestic supply of generic drugs is dominated by leading enterprises such as Hengrui Medicine and Yangtze River Pharmaceutical Group. After the centralized procurement of preparations, the price has dropped by more than 80%, driving a significant improvement in clinical accessibility, and the demand for upstream API has risen simultaneously, with the annual demand growth rate remaining above 25%.

The original research enterprise of esketamine is Johnson & Johnson. The trade name of the original nasal spray formulation is Spravato, and the trade name of the oral formulation is Ketanest. Its core compound patent expired in the United States in 2019, and the Chinese compound patent expired in 2021. The already marketed formulations mainly include nasal spray (specification: 28mg/spray) and injection (specifications: 2ml:50mg, 5ml:125mg). Relevant formulations have all been included in the FDA Reference Listed Drug Catalog, among which the injection has also been included in China's *Catalog of Reference Preparations for Chemical Drugs*. Up to now, there have been 11 esketamine API registration entries on the CDE API registration platform, including those from Hengrui Medicine and Kelun Pharma, 9 of which are in status A; 6 domestic enterprises have obtained marketing approval for esketamine injection, and the original nasal spray formulation was approved for import by the NMPA in 2019. (Data as of October 2025, please refer to the official CDE website for the latest information)

CATO provides a full set of impurity reference standards for esketamine API. Most products are available directly from stock. Spot orders paid before 16:00 can be shipped on the same day. All products meet the requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can fully meet the reference standard use needs of pharmaceutical enterprises in all stages of API R&D, quality research and registration declaration.