SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Zhang Jack Y. (Last) (First) (Middle) C/O AMPHASTAR PHARMACEUTICALS, INC. 11570 6TH STREET (Street) RANCHO CUCAMONGA, CA 91730 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Amphastar Pharmaceuticals, Inc. [ AMPH ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner X Officer (give title below) Other (specify below) CEO & Chief Scientific Officer
	3. Date of Earliest Transaction (Month/Day/Year) 03/16/2023
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/16/2023		G		57,365	D	$0.00	0	I	See footnote(1)
Common Stock	03/16/2023		G		57,365	D	$0.00	0	I	See footnote(2)
Common Stock	03/16/2023		F		25,241(3)	D	$37.6	2,094,486(4)	D
Common Stock	03/16/2023		F		9,998(3)	D	$37.6	1,462,654(5)	I	See footnote(6)
Common Stock	03/17/2023		F		15,768(3)	D	$36.29	2,078,718	D
Common Stock	03/17/2023		F		7,052(3)	D	$36.29	1,455,602	I	See footnote(6)
Common Stock								6,827,679	I	See footnote(7)
Common Stock								5,000	I	See footnote(8)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Zhang Jack Y. (Last) (First) (Middle) C/O AMPHASTAR PHARMACEUTICALS, INC. 11570 6TH STREET (Street) RANCHO CUCAMONGA, CA 91730 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner X Officer (give title below) Other (specify below) CEO & Chief Scientific Officer

1. Name and Address of Reporting Person* Luo Mary Z. (Last) (First) (Middle) C/O AMPHASTAR PHARMACEUTICALS, INC. 11570 6TH STREET (Street) RANCHO CUCAMONGA, CA 91730 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner X Officer (give title below) Other (specify below) COO,Chief Scientist & Chairman

Explanation of Responses:

1. The shares are held of record by The Jack Y. Zhang 2020 GRAT dated February 7, 2020, Jack Y. Zhang trustee (the "Zhang GRAT"). On February 7, 2020, Dr. Zhang contributed 353,797 shares of directly held Issuer common stock to the Zhang GRAT for the benefit of himself and his three adult children (the "Distributees"). Pursuant to the terms of the Zhang GRAT, upon termination of the Zhang GRAT, 57,365 of the shares were distributed to Distributees. The remaining 296,431 shares representing annuity payments under the Zhang GRAT were previously distributed to Dr. Zhang and continue to be reported in this Form 4 as directly owned by Dr. Zhang.

2. The shares are held of record by The Mary Z. Luo 2020 GRAT dated February 7, 2020, Mary Z. Luo trustee (the "Luo GRAT"). On February 7, 2020, Dr. Luo contributed 353,797 shares of directly held Issuer common stock to the Luo GRAT for the benefit of herself and her three adult children (the "Distributees"). Pursuant to the terms of the Luo GRAT, upon termination of the Luo GRAT, 57,365 of the shares were distributed to Distributees. The remaining 296,431 shares representing annuity payments under the Luo GRAT were previously distributed to Dr. Luo and continue to be reported in this Form 4 as directly owned by Dr. Luo.

3. The reported shares were withheld to satisfy the reporting person's tax liability in connection with the vesting of restricted stock units, or RSUs.

4. Excludes 57,365 shares previously reported as held directly by Dr. Zhang as described in footnote (1) above.

5. Excludes 57,365 shares previously reported as held directly by Dr. Luo as described in footnote (2) above.

6. The securities are held of record by Dr. Luo. The reporting persons are husband and wife.

7. The shares are held of record by Applied Physics & Chemistry Laboratories, Inc., of which the reporting persons and The Bill Luobei Zhang 2004 Irrevocable Trust are the sole owners.

8. 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.

	/s/ Eva Wen, by power of attorney for Jack Y. Zhang	03/20/2023
	/s/ Eva Wen, by power of attorney for Mary Z. Luo	03/20/2023
	** Signature of Reporting Person	Date
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