X0206 3/A 2014-06-24 2014-06-24 0 0001297184 Amphastar Pharmaceuticals, Inc. AMPH 0001611148 Shandell Jason B. C/O AMPHASTAR PHARMACEUTICALS, INC. 11570 6TH STREET RANCHO CUCAMONGA CA 91730 1 1 0 0 President Common Stock 3332 D The reported shares are represented by deferred stock units, or DSUs, which vest in five equal annual installments beginning on August 2, 2010. This amended Form 3 is filed to correct the amount of DSUs held by the reporting person. The prior Form 3 reported 666 DSUs. This error in column 2 of Table I also appears in subsequent Forms 4 filed through October 6, 2015. /s/ Ken Stupak, by power of attorney 2016-02-03