Amphastar Pharmaceuticals, Inc. engages in developing, manufacturing, marketing, and selling technically challenging generic and proprietary injectable, inhalation, and intranasal products, and insulin active pharmaceutical ingredient. The company is headquartered in Rancho Cucamonga, California and currently employs 2,028 full-time employees. The company went IPO on 2014-06-25. Additionally, it sells insulin API products. Most of its finished products are used in hospital or urgent care clinical settings and are primarily contracted and distributed through group purchasing organizations and drug wholesalers. Its segments include finished pharmaceutical products and API products. The finished pharmaceutical products segment manufactures, markets and distributes Primatene MIST, epinephrine, glucagon, phytonadione, lidocaine, enoxaparin, naloxone, as well as various other critical and non-critical care drugs. The API segment manufactures and distributes RHI API and porcine insulin API for external customers and internal product development. Its pipeline has over 20 product candidates, including generic ANDAs, biosimilar, and others.