Doxepin

In the clinical treatment of mental disorders, tricyclic antidepressants are a category of basic medications that combine cost-effectiveness with proven efficacy, and doxepin is a representative variety among them. It inhibits the reuptake of serotonin and norepinephrine by the central nervous system, increases the concentrations of these two neurotransmitters in the synaptic cleft, and thus exerts antidepressant and anxiolytic effects. Meanwhile, it also has certain sedative and antihistamine effects, and is clinically mainly used for the treatment of various types of depression and anxiety neurosis. It is more applicable to patients with mental disorders accompanied by sleep disorders, and low-dose dosage forms can also be used for symptom relief of idiopathic urticaria in adults.

At the current stage, the domestic doxepin preparation market size is stable in the range of 300 to 500 million yuan, with a compound annual growth rate of approximately 2.1% in the past three years. The overall growth is moderate, and it belongs to the mature category of psychotropic drugs. The competitive landscape is dominated by generic drugs. There are more than 12 manufacturers of oral preparations that have passed the consistency evaluation, and the procurement proportion in public medical institutions exceeds 85%. Among them, the 50mg tablet has been included in the third batch of national centralized drug procurement, and the winning bid price has dropped by more than 90% compared with the original research product, which greatly improves the accessibility in primary medical institutions. The demand for upstream API also shows a trend of concentrating on large-scale manufacturers.

The original research enterprise of doxepin is Roche, and the original research brand name is Sinequan. Its core compound patent expired globally in 1985. The main dosage forms of the original research are tablets, with specifications including 10mg, 25mg, 50mg, 75mg, 100mg and 150mg, which have been included in the FDA Reference Listed Drug Catalog. On the domestic front, there are currently 6 registration records of doxepin (doxepin hydrochloride) API on the CDE API registration platform, among which 3 are in Status A and can be formally associated with the review and approval of domestic preparations. Two dosage forms, doxepin hydrochloride tablets and doxepin hydrochloride cream, have been approved for marketing in China, and multiple enterprises have passed the consistency evaluation for doxepin hydrochloride tablets. (Data as of October 2024, please refer to the official CDE website for the latest information)

In response to the demand for impurity reference standards in the R&D and quality control process of doxepin API, CATO can provide a full set of impurity reference standards for this API. Relevant products meet the compliance requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA. Most products are in regular stock, and orders placed before 16:00 can be shipped on the same day, which can fully meet the usage needs of various scenarios such as drug R&D, quality research, and routine release testing.