Mirtazapine

In response to the imbalance of 5-hydroxytryptamine and norepinephrine neurotransmitter conduction that patients with depression often face, mirtazapine, as a noradrenergic and specific serotonergic antidepressant (NaSSA), enhances the release of norepinephrine and 5-hydroxytryptamine by blocking the α₂ adrenergic receptor on the central presynaptic membrane, and selectively blocks 5-hydroxytryptamine 2 and 5-hydroxytryptamine 3 receptors, which greatly reduces the common adverse reactions of traditional antidepressants such as anxiety, nausea and sexual dysfunction. In clinical practice, it is suitable for the acute phase treatment of moderate and severe depression, and can also be used for consolidation and prevention of recurrence in the maintenance phase, and has particularly prominent advantages for elderly depressed patients with concomitant insomnia and weight loss.

At present, the global antidepressant market size has exceeded 15 billion US dollars. With the characteristics of good tolerance and fast onset of action, mirtazapine accounts for about 3.6% of the overall antidepressant market share, and the annual sales of terminal public medical institutions in China alone are stable at more than 800 million yuan. Its compound patent has long expired. At present, there are more than 80 domestic generic drug preparation approvals. In the seventh batch of national centralized drug procurement in 2022, the average price of mirtazapine oral regular-release dosage forms was reduced by 48%, which further improved the accessibility of medication at the primary level. The demand for upstream API has continued to expand with the implementation of centralized procurement, and the annual compound growth rate of domestic mirtazapine API consumption in the past three years has reached 12.3%.

The original research enterprise of mirtazapine is Organon of the Netherlands (now affiliated to Merck & Co., Inc.), and the original research trade name is "Remeron". The core compound patent expired globally in 2004. At present, the main dosage form of the original research drug marketed in China is oral tablet, with specifications including 15mg and 30mg, which has been included in the *Catalogue of Reference Preparations for Chemical Drugs* issued by the National Medical Products Administration, and is also a reference preparation included by the FDA. In terms of domestic API registration, mirtazapine APIs submitted by 8 enterprises including Huahai Pharmaceutical and Kelun Pharmaceutical have obtained CDE registration numbers (A status), and more than 30 domestic mirtazapine preparation varieties have been approved for marketing. (Data as of June 2025, please refer to the official CDE website for the latest information)

CATO can provide a full set of mirtazapine impurity reference standards. Most products are available directly from stock. Spot orders placed before 16:00 can be shipped on the same day. All products meet the requirements of pharmacopoeias of China, FDA and other national drug regulatory regulations, and can fully meet the needs of pharmaceutical enterprises in API quality research, consistency evaluation and routine production testing.