144 0001047579 XXXXXXXX LIVE 0001297184 Amphastar Pharmaceuticals, Inc. 001-36509 11570 6th Street Rancho Cucamonga CA 91730 909-980-9484 Richard Prins Executive Common Stock UBS Financial Services Inc

1000 Harbor Blvd 3rd Floor Weehawken NJ 07086

10000 440000 48730000 12/09/2024 Nasdaq Common Stock 12/09/2024 Option Exercise Issuer N 10000 12/09/2024 Cash N Richard Prins

11570 Sixth St Rancho Cucamonga CA 91730

Common Stock 11/12/2024 2500 121992 Richard Prins

11570 Sixth St Rancho Cucamonga CA 91730

Common Stock 12/09/2024 2500 121992 12/09/2024 /s/ UBS Financial Services Inc, as attorney-in-fact for Richard Prins