Amphastar Pharmaceuticals Inc (NASDAQ: AMPH) has gained US approval for its Isoproterenol Hydrochloride Injection, the company announced on Tuesday.

The US Food and Drug Administration (FDA) has approved Amphastar's abbreviated new drug application for Isoproterenol Hydrochloride Injection, USP 0.2mg/mL, 1mL and 0.2mg/mL, 5mL single dose vial, with indications for multiple uses including for mild or transient episodes of heart block that do not require electric shock or pacemaker therapy.

Amphastar's product was determined by the FDA to be therapeutically equivalent to Isuprel (Isoproterenol Hydrochloride Injection) which is sold in the United States by Valeant Pharmaceuticals.

The active pharmaceutical ingredient for the product is manufactured by Amphastar's Chinese subsidiary, Amphastar Nanjing Pharmaceuticals Co Ltd.

Welcoming the approval, Amphastar's CEO, Dr Jack Zhang, noted that Isoproterenol Hydrochloride Injection currently only has one other generic vial in the market.

According to IQVIA, US brand and generic sales of Isoproterenol Hydrochloride Injection, 0.2 mg/mL, 1mL and 0.2mg/mL, 5mL vials and ampules totalled approximately USD147m for the 12 months ended 31 March 2018.

Amphastar expects to launch its product in the third quarter of 2018.