On August 4, 2022, the Board of Directors of Amphastar Pharmaceuticals, Inc. upon the recommendation of the Nominating and Corporate Governance Committee of the Board approved an increase to the authorized number of directors permitted to serve on the Board from eight (8) to ten (10) directors and appointed each of William J. Peters, the Company's Chief Financial Officer, Executive Vice President of Finance, and Treasurer, and Jacob Liawatidewi, the Company's Executive Vice President of Corporate Administration Center, and Sales and Marketing (together with Mr. Peters, the “New Directors”), to serve as Class I directors, to hold office until the Company's 2023 annual meeting of stockholders and until each such director's successor is duly elected and qualified or until each such director's earlier death, resignation or removal, effective immediately. The Board also determined that Diane G. Gerst does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director that, including Ms. Gerst, six of the Company's current directors are independent of within the meaning of the listing standards of the Nasdaq Stock Market LLC.