Zhejiang Chemsyn

Zhejiang Chemsyn Pharm Co., Ltd. (also known as Zhejiang Haisheng Pharmaceutical) is a leading Chinese pharmaceutical company specializing in the development and large-scale manufacturing of active pharmaceutical ingredients (APIs) and chemical intermediates. Founded in 2007 and headquartered in Quzhou, Zhejiang, the company has established itself as a major global supplier of sulfonamides and other small molecule drugs for both human and veterinary use. Its core product portfolio includes antipyretics, analgesics, and antibacterials such as Celecoxib, Moxifloxacin, and various sulfa-based compounds. Operating as a CMO/CDMO, Zhejiang Chemsyn provides high-quality chemical synthesis services and maintains certifications from global regulatory bodies including the NMPA, EU CEP, and PMDA. The company is publicly listed on the Beijing Stock Exchange under the ticker 920656.BJ.