Amphastar Pharmaceuticals, Inc. — Director's Dealing 2018

May 18, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Amphastar Pharmaceuticals, Inc. (AMPH)
CIK: 0001297184
Period of Report: 2018-05-15

Reporting Person: Zhang Jack Y. (Director, CEO & Chief Scientific Officer, 10% Owner)
Reporting Person: Luo Mary Z. (Director, COO,Chief Scientist & Chairman, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-15	Common Stock	P	25000	$16.0788	Acquired	2065619	Direct
2018-05-16	Common Stock	P	15000	$16.0569	Acquired	2080619	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1346129	Indirect
Common Stock	7461594	Indirect
Common Stock	5000	Indirect
Common Stock	200000	Indirect

Footnotes

F1: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $15.762 to $16.50 inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnotes (1) and (2) to this Form 4.

F2: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $15.997 to $16.063, inclusive.

F3: The securities are held of record by Mary Z. Luo. The reporting persons are husband and wife.

F4: The shares are held of record by APCL, of which the reporting persons and The Bill Luobei Zhang 2004 Irrevocable Trust (the "BLZ Trust") are the sole owners.

F5: The shares are held of record in an account for the benefit of the reporting persons' son. The reporting persons disclaim beneficial ownership of these shares, and the inclusion of these shares in this report should not be deemed an admission of beneficial ownership of any such shares for purposes of Section 16, or for any other purpose.

F6: The shares are held of record by the BLZ Trust. The reporting persons disclaim beneficial ownership of these shares, and the inclusion of these shares in this report should not be deemed an admission of beneficial ownership of any such shares for purposes of Section 16, or for any other purpose.