Form 4 Filing for David Russell Gaugh

David Russell Gaugh, a director at Amphastar Pharmaceuticals, Inc., acquired 8,143 shares of Common Stock on June 1, 2026, valued at $0.00 per share. These shares are represented by restricted stock units that vest on June 1, 2027. Additionally, Gaugh was granted a stock option to purchase 17,365 shares of Common Stock, also with a vesting date of June 1, 2027. The option has an exercise price of $18.42 and expires on June 1, 2036. Following these transactions, Gaugh directly owns 14,447 shares of Common Stock and holds options for 17,365 shares.