Silodosin

Benign prostatic hyperplasia (BPH) is a highly prevalent degenerative urinary system disease among middle-aged and elderly men. Its incidence can rise to over 50% with increasing age, and symptoms such as dysuria, frequent urination and urgent urination severely affect patients' quality of life. Silodosin is a highly selective α1A adrenoceptor antagonist. It specifically blocks α1A receptors in the prostate, bladder neck and urethra, relaxes smooth muscles and reduces urethral pressure. Its effect on blood pressure is significantly lower than that of non-selective drugs of the same category. It is indicated for improving lower urinary tract symptoms caused by BPH, especially suitable for elderly patients with comorbid hypertension, and has outstanding advantages in clinical tolerance.

The global market size of silodosin was approximately USD 1.28 billion in 2023, with a compound annual growth rate maintained at 4.2%. The growth momentum mainly comes from the accelerated global aging process and the increasing demand of patients for drugs with low side effects. In terms of the domestic market, the sales volume in sample hospitals exceeded RMB 1.8 billion in 2024, and the generic drug substitution rate has reached 72%. At present, 13 domestic enterprises have obtained the approval documents for silodosin preparations. On the API supply side, in addition to the original manufacturer, 8 domestic enterprises have completed CDE API registration, leading to a relatively sufficient market competition pattern. After centralized procurement, the terminal price has dropped by more than 60%, and the accessibility for patients has been greatly improved.

The original research enterprise of silodosin is Daiichi Sankyo Co., Ltd. of Japan, with the original brand name "Urief". Its core compound patent expired in 2016 and 2019 in Japan and the United States respectively, and the compound patent in China expired in 2018. The main dosage form approved for the original drug is capsule, with specifications of 4mg and 8mg. The 4mg specification has been included in the Reference Listed Drug Catalogue of China Marketed Drugs, and is also listed in the FDA Reference Listed Drug Catalogue. At present, 11 domestic silodosin APIs have obtained A status through CDE registration, and the corresponding approved preparation varieties include capsules and sustained-release tablets, which can fully meet the domestic production demand of generic drugs. (Data as of June 2025, please refer to the official CDE website for the latest information)

In response to the needs of silodosin generic drug development and quality control, CATO provides a full set of impurity reference standards for this API, covering process impurities, degradation impurities and isomer impurities. The products meet the compliance requirements of multiple regulations such as Chinese Pharmacopoeia and FDA. Most impurities are available in stock. Stock orders placed before 16:00 can be shipped on the same day, which can provide efficient and reliable material basis support for enterprises' R&D and quality testing links.