Amphastar Pharmaceuticals filings document the regulatory disclosures of a Delaware biopharmaceutical company focused on generic and proprietary injectable, inhalation, and intranasal products, along with active pharmaceutical ingredient products. Form 8-K reports furnish operating results, product revenue commentary, non-GAAP measures, and material business updates tied to the company's pharmaceutical products business.
Amphastar's SEC filings also cover governance and capital-structure matters, including proxy disclosures, executive compensation, employment agreements, equity-compensation dilution, and share repurchase authorizations. Material agreement filings describe licensing rights for a corticotropin compound, supply arrangements involving a Chinese subsidiary, related-party review procedures, and commercial terms that affect the company's pipeline, manufacturing, and distribution activities.
Amphastar Pharmaceuticals senior executive Rong Zhou reported a routine tax-withholding share disposition tied to restricted stock units. On March 15, 2026, 1,225 shares of common stock were withheld at $18.18 per share to satisfy tax liabilities from RSU vesting.
After this transaction, Zhou directly held 171,554 Amphastar shares. Footnotes show additional indirect holdings of 99,668 shares held by the Zhou Family Trust, where Zhou serves as trustee, and 5,000 shares held by Zhou’s spouse.
Amphastar Pharmaceuticals CFO William J. Peters reported a routine tax-related share disposition. On the vesting of restricted stock units, 1,973 shares of common stock were withheld at $18.18 per share to satisfy his tax liability, rather than sold on the open market.
After this withholding, Peters directly holds 175,063 shares of Amphastar common stock. This filing reflects a compensation-driven, non-discretionary tax-withholding event, not an open-market purchase or sale decision.
Amphastar Pharmaceuticals reported insider share movements tied to routine tax withholding on vested restricted stock units. On the reported date, entities associated with executives Jack Y. Zhang and Mary Z. Luo delivered a total of 12,692 shares of common stock at $18.18 per share to satisfy tax liabilities, classified as tax-withholding dispositions rather than open-market sales.
Following these transactions, Zhang is shown holding 2,990,052 shares directly, while related entities report 6,827,679 shares held indirectly. Luo-related holdings include 1,245,125 shares held of record. These entries reflect compensation-related mechanics and leave substantial equity positions in place.
Amphastar Pharmaceuticals reported that its Board of Directors authorized a $50 million increase to the company’s share buyback program, effective March 12, 2026. The program is intended primarily to offset dilution from equity compensation grants over time.
Repurchases may occur over an indefinite period through open-market purchases, private block trades, Rule 10b5-1 plans, privately negotiated deals, or other methods permitted by law. The timing and actual number of shares bought back will depend on the share price, corporate and regulatory requirements, and other conditions.
Amphastar Pharmaceuticals CFO William J. Peters reported equity compensation and related tax withholding transactions. On March 9, 2026, he received 58,693 shares of Common Stock in the form of restricted stock units that vest in four equal annual installments beginning on March 9, 2027.
On the same date, he was granted an employee stock option covering 121,071 shares of Common Stock at an exercise price of $19.21 per share, expiring in 2036, also vesting in four equal annual installments beginning on March 9, 2027. On March 10, 2026, 3,297 shares of Common Stock were withheld to cover his tax liabilities from RSU vesting, leaving him with 177,036 shares of Common Stock held directly.
Amphastar Pharmaceuticals, Inc. senior executive Rong Zhou reported routine equity compensation and related tax withholding. On March 9, 2026, Zhou received 39,432 restricted stock units (RSUs) and an option for 81,341 shares of common stock at $19.21 per share, both vesting in four equal annual installments beginning on March 9, 2027. A separate entry on March 10, 2026 shows 2,215 common shares withheld at $18.91 per share to cover taxes on RSU vesting, which is characterized as a tax-withholding disposition rather than an open-market sale. After these transactions, Zhou holds 172,779 common shares directly, in addition to indirect holdings of 99,668 shares through the Zhou Family Trust and 5,000 shares held by a spouse, plus the newly granted option for 81,341 shares.
Amphastar Pharmaceuticals EVP Liawatidewi Yakob reported routine equity compensation and related tax withholding. She received 35,450 shares of Common Stock in the form of restricted stock units that vest in four equal annual installments beginning on March 9, 2027. She was also granted employee stock options for 73,126 shares of Common Stock at an exercise price of $19.21 per share, vesting in four equal annual installments starting on March 9, 2027 and expiring in 2036. In connection with RSU vesting, 1,870 shares of Common Stock were withheld to satisfy tax liabilities, a non‑market disposition. Following these events, she holds 122,925 Common Stock shares directly, 2,459 shares indirectly through the Yakob and Sunmoon Trust, and the newly granted 73,126 stock options.
Amphastar Pharmaceuticals insiders reported routine equity compensation and related tax withholding. CEO Jack Y. Zhang and COO Mary Z. Luo, who are also major shareholders and directors, received grants of restricted stock units (RSUs) and employee stock options tied to common stock. The RSUs, totaling 180,504 shares held directly and 72,462 shares held indirectly, vest in four equal annual installments beginning on March 9, 2027. They also received employee stock options for 372,338 shares held directly and 149,472 shares held indirectly, with a $19.21 exercise price and the same four-year vesting schedule. In connection with RSU vesting, 14,785 directly held shares and 4,395 indirectly held shares of common stock were withheld at $18.91 per share to cover tax liabilities, a non‑market transaction. Following these updates, reported holdings include 3,014,621 shares of common stock held directly, 1,252,428 shares held indirectly, and 6,827,679 additional shares held indirectly through Applied Physics and Chemistry Laboratories, Inc. and a related trust.
Amphastar Pharmaceuticals director and CFO William J. Peters reported a routine tax-related share disposition. On March 6, 2026, 2,146 shares of common stock were withheld at $19.34 per share to satisfy his tax liability from vesting restricted stock units. After this withholding, he directly owned 121,640 shares of Amphastar common stock.
Amphastar Pharmaceuticals senior executive Rong Zhou reported a routine tax-related share disposition. On March 6, 2026, 1,357 shares of common stock were withheld at $19.34 per share to cover taxes from vesting restricted stock units. After this withholding, Zhou directly held 135,562 shares, with additional indirect holdings of 99,668 shares through the Zhou Family Trust and 5,000 shares held by the spouse, as noted in the footnotes. This filing reflects compensation- and tax-driven activity rather than an open-market trade.