Paroxetine

Depressive disorder is one of the mental diseases with the highest incidence rate in the world, and its onset is closely related to the imbalance of serotonin (5-HT) neurotransmitter concentration. Paroxetine is an antidepressant belonging to the class of selective serotonin reuptake inhibitors (SSRIs). It highly selectively blocks the reuptake of 5-HT by the presynaptic membrane, prolongs the action time of 5-HT in the synaptic cleft, and thus improves depressive mood. This drug is not only applicable to various types of depressive disorders, including depression with anxiety and reactive depression, but also can be used for the treatment of obsessive-compulsive neurosis, social anxiety disorder, panic disorder, post-traumatic stress disorder and other mental diseases. It is one of the first-line drugs for the clinical treatment of mental diseases in adults.

The global market size of paroxetine has remained above USD 2 billion for a long time, and the annual sales in the Chinese market are approximately RMB 1.5 billion. In recent years, with the increase in the consultation rate of mental diseases, the annual growth rate has maintained at 6%~8%. At present, the domestic market has a coexistence of original research drugs and generic drugs. More than 20 enterprises have been approved to produce paroxetine-related preparations. This variety has been included in the national centralized procurement, and the price of the selected preparations has dropped by more than 80%. The demand for APIs with high cost performance and compliance from downstream generic pharmaceutical enterprises continues to rise, driving the steady expansion of the upstream API market size.

The original research enterprise of paroxetine is GlaxoSmithKline, with the original trade name Seroxat. The core compound patent of paroxetine expired around 2003 in major global markets, and the compound patent in China has also expired. The main dosage forms approved for the original research include tablets with a specification of 20 mg, and sustained-release tablets with specifications of 12.5 mg and 25 mg. Both the original tablets and sustained-release tablets have been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and also listed in the FDA Reference Preparations Catalogue. At present, paroxetine APIs from more than 30 enterprises in China have been registered with the CDE (status A), and the preparations approved for marketing cover multiple dosage forms such as conventional tablets, enteric-coated sustained-release tablets, and sustained-release capsules. (Data as of October 2024, please refer to the official website of CDE for the latest information)

CATO can provide a full set of impurity reference standards for paroxetine API, fully covering the whole chain research requirements of starting materials, intermediates, degradation impurities, etc. Most products are in sufficient stock. For in-stock products, orders placed before 16:00 can be shipped on the same day. All reference standards meet the requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can fully meet the technical requirements of API and preparation enterprises in various scenarios such as quality research, consistency evaluation, and registration declaration.