# EDGAR Filing Document

**Accession Number:** 0001297184
**File Stem:** 0001297184-23-000022
**Filing Date:** 2023-3
**Character Count:** 32634
**Document Hash:** e612b80c745a6dc016efc9a141e78144
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001297184-23-000022.hdr.sgml**: 20230301

**ACCESSION NUMBER**: 0001297184-23-000022

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 5

**FILED AS OF DATE**: 20230301

**DATE AS OF CHANGE**: 20230301

**EFFECTIVENESS DATE**: 20230301

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Amphastar Pharmaceuticals, Inc.
- **CENTRAL INDEX KEY:** 0001297184
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 330702205
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-270180
- **FILM NUMBER:** 23693996

**BUSINESS ADDRESS:**
- **STREET 1:** 11570 SIXTH STREET
- **CITY:** RANCHO CUCAMONGA
- **STATE:** CA
- **ZIP:** 91730
- **BUSINESS PHONE:** 909-980-9484

**MAIL ADDRESS:**
- **STREET 1:** 11570 SIXTH STREET
- **CITY:** RANCHO CUCAMONGA
- **STATE:** CA
- **ZIP:** 91730

**As filed with the Securities and Exchange Commission on March 1, 2023**

**Registration No. 333-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**

**UNITED STATES<br>SECURITIES AND EXCHANGE COMMISSION<br>Washington, D.C. 20549**

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**FORM S-8<br>REGISTRATION STATEMENT<br>*UNDER<br>THE SECURITIES ACT OF 1933***

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**AMPHASTAR PHARMACEUTICALS, INC.<br>(Exact name of Registrant as specified in its charter)**

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| | | | | |
|:---|:---|:---|:---|:---|
| **Delaware** |  |  |  | **33-0702205** |
| **(State or other jurisdiction of<br>incorporation or organization)** |  |  |  | **(I.R.S. Employer<br>Identification Number)** |

---

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**11570 6th Street<br>Rancho Cucamonga, California 91730<br>(Address, including Zip Code, of Principal Executive Offices)**

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**Amended and Restated 2015 Equity Incentive Plan <br>(Full title of the plan)**

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**Jack Y. Zhang<br>Chief Executive Officer, President and Director<br>Amphastar Pharmaceuticals, Inc.<br>11570 6th Street<br>Rancho Cucamonga, California 91730<br>(909) 980-9484<br>(Name, address and telephone number, including area code, of agent for service)**

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***Copies to:***

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| | |
|:---|:---|
|  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**<br>Amphastar Pharmaceuticals, Inc.<br>11570 6th Street<br>Rancho Cucamonga, California 91730<br>(909) 980-9484**<br>|
| **<br>Andrew D. Hoffman<br>Wilson Sonsini Goodrich & Rosati, P.C.<br>650 Page Mill Road<br>Palo Alto, California 94304<br>(650) 493-9300** | **William J. Peters** <br>**Chief Financial Officer <br>Amphastar Pharmaceuticals, Inc.<br>11570 6th Street<br>Rancho Cucamonga, California 91730<br>(909) 980-9484** |

---

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Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer", "smaller reporting company", and "emerging growth company" in Rule 12b-2 of the Exchange Act.

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| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;Large accelerated filer | &nbsp;&nbsp;⌧ | &nbsp;&nbsp;Accelerated filer | &nbsp;&nbsp;◻ |
| &nbsp;&nbsp;Non-accelerated filer | &nbsp;&nbsp;◻ | &nbsp;&nbsp;Smaller reporting company | &nbsp;&nbsp;◻ |
|  |  | &nbsp;&nbsp;Emerging growth company | &nbsp;&nbsp;◻ |

---

If an emerging growth company, indicate by check mark if the Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ◻

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**EXPLANATORY NOTE**

This Registration Statement on Form S-8 (the "Registration Statement") registers 1,202,802 additional shares of common stock of Amphastar Pharmaceuticals, Inc. (the "Registrant") under the Registrant's Amended and Restated 2015 Equity Incentive Plan (the "2015 Plan") for which a registration statement (File No. 333-205470) on Form S-8 was filed with the Securities and Exchange Commission (the "Commission") on July 2, 2015 (the "Initial S-8"). Pursuant to General Instruction E to Form S-8, the contents of the Initial S-8 are incorporated by reference into this Registration Statement, except that the provisions contained in Parts I and II of the Initial S-8 are modified as set forth in this Registration Statement. The number of shares of the Registrant's common stock available for grant and issuance under the 2015 Plan is subject to an annual increase on the first day of each fiscal year starting on January 1, 2016, by an amount equal to the least of (i) 3,000,000 shares, (ii)) two and one-half percent (2.5%) of the outstanding shares of common stock on the last day of the immediately preceding fiscal year or (iii) such number of shares of common stock determined by the Board. On January 1, 2023, the number of shares of the Registrant's common stock available for grant and issuance under the 2015 Plan increased by 1,202,802 shares. This Registration Statement registers such additional shares of the Registrant's common stock, which were available for grant and issuance under the 2015 Plan as of January 1, 2023.

**PART I** 

**INFORMATION REQUIRED IN THE PROSPECTUS** 

The information specified in Item 1 and Item 2 of Part I of Form S-8 is omitted from this Registration Statement in accordance with the provisions of Rule 428 under the Securities Act of 1933, as amended (the "Securities Act") and the introductory note to Part I of Form S-8. The documents containing the information specified in Part I of Form S-8 will be delivered to the participants in the equity benefit plans covered by this Registration Statement as specified by Rule 428(b)(1) under the Securities Act.

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#### PART II

#### INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

#### Item 3. Incorporation of Documents by Reference.
The Registrant hereby incorporates by reference in this Registration Statement the following documents and information previously filed with the Commission:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) The Registrant's Annual Report on [Form 10-K](https://www.sec.gov/ix?doc=/Archives/edgar/data/1297184/000129718423000019/amph-20221231x10k.htm) for the fiscal year ended December 31, 2022, filed with the Commission on March 1, 2023 pursuant to Section 13(a) of the Securities Exchange Act of 1934, as amended (the "Exchange Act");

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) All other reports filed by the Registrant with the Commission pursuant to Sections 13(a) or 15(d) of the Exchange Act since the end of the fiscal year covered by the Registrant's Annual Report referred to in (1) above; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) The description of the Registrant's common stock contained in the Registrant's Registration Statement on [Form 8-A](https://www.sec.gov/Archives/edgar/data/1297184/000110465914046607/a12-26441_108a12b.htm) (File No. 001-36509) filed with the Commission on June 18, 2014, pursuant to Section 12(b) of the Exchange Act, including any amendment or report filed for the purpose of updating such description.

All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act on or after the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement that indicate that all securities offered have been sold or that deregisters all securities then remaining unsold shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date of filing of such documents; *provided*, *however*, that documents or information deemed to have been furnished and not filed in accordance with the rules of the Commission shall not be deemed incorporated by reference into this Registration Statement.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

**Item 4. Description of Securities.**

Not applicable.

**Item 5. Interests of Named Experts and Counsel.**

Not applicable.

**Item 6. Indemnification of Directors and Officers.**

Section 102 of the General Corporation Law of the State of Delaware permits a corporation to eliminate the personal liability of directors of a corporation to the corporation or its stockholders for monetary damages for a breach of fiduciary duty as a director, except for breaches of the director's duty of loyalty to the corporation or its stockholders, acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of a law, authorizations of the payments of a dividend or approval of a stock repurchase

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or redemption in violation of Delaware corporate law or for any transactions from which the director derived an improper personal benefit. The Registrant's amended and restated certificate of incorporation provides that no director will be liable to the Registrant or its stockholders for monetary damages for breach of fiduciary duties as a director, subject to the same exceptions as described above. The Registrant has entered into separate indemnification agreements with each of its directors which may, in some cases, be broader than the specific indemnification provisions contained under Delaware law. These indemnification agreements generally require the Registrant, among other things, to indemnify its directors against liabilities that may arise by reason of their status or service as directors. These indemnification agreements also generally require the Registrant to advance any expenses incurred by the directors as a result of any proceeding against them as to which they could be indemnified. The Registrant also has purchased and expects to maintain standard insurance policies that provide coverage (1) to its directors and officers against loss arising from claims made by reason of breach of duty or other wrongful act and (2) to it with respect to indemnification payments it may make to such officers and directors.

Section 145 of the General Corporation Law of the State of Delaware provides that a corporation has the power to indemnify a director, officer, employee, or agent of the corporation and certain other persons serving at the request of the corporation in related capacities against expenses (including attorneys' fees), judgments, fines and amounts paid in settlements actually and reasonably incurred by the person in connection with a threatened, pending, or completed action, suit or proceeding to which he or she is or is threatened to be made a party by reason of such position, if such person acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, and, in any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful, except that, in the case of actions brought by or in the right of the corporation, indemnification is limited to expenses (including attorneys' fees) actually and reasonably incurred by the person in connection with defense or settlement of such action or suit and no indemnification shall be made with respect to any claim, issue, or matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery or such other court shall deem proper. In addition, to the extent that a present or former director or officer of a corporation has been successful on the merits or otherwise in defense of any action, suit, or proceeding described above (or claim, issue, or matter therein), such person shall be indemnified against expenses (including attorneys' fees) actually and reasonably incurred by such person in connection therewith. Expenses (including attorneys' fees) incurred by an officer or director in defending any civil, criminal, administrative, or investigative action, suit, or proceeding may be advanced by the corporation upon receipt of an undertaking by such person to repay such amount if it is ultimately determined that such person is not entitled to indemnification by the corporation under Section 145 of the General Corporation Law of the State of Delaware.

The Registrant's amended and restated certificate of incorporation provide that it will, to the fullest extent permitted by law, indemnify any person made or threatened to be made a party to an action or proceeding by reason of the fact that he or she (or his or her testators or intestate) is or was a director or officer of the Registrant or serves or served at any other corporation, partnership, joint venture, trust or other enterprise in a similar capacity or as an employee or agent at the Registrant's request, including service with respect to employee benefit plans maintained or sponsored by the Registrant, against expenses (including attorneys'), judgments, fines, penalties and amounts paid in settlement incurred in connection with the investigation, preparation to defend, or defense of such action, suit, proceeding, or claim. However, the Registrant is not required to indemnify or advance expenses in connection with any action, suit, proceeding, claim, or counterclaim initiated by it or on behalf of it. The Registrant's amended and restated bylaws provide that it will indemnify and hold harmless each person who was or is a party or threatened to be made a party to any action, suit, or proceeding by reason of the fact that he or she is or was a director or officer of the

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Registrant, or is or was serving at the Registrant's request in a similar capacity of another corporation, partnership, joint venture, trust or other enterprise, including service with respect to employee benefit plans (whether the basis of such action, suit, or proceeding is an action in an official capacity as a director or officer or in any other capacity while serving as a director of officer) to the fullest extent authorized by the Delaware General Corporation Law against all expense, liability and loss (including attorneys' fees, judgments, fines, ERISA excise taxes, or penalties and amounts paid in settlement) reasonably incurred or suffered by such person in connection with such action, suit or proceeding, and this indemnification continues after such person has ceased to be an officer or director and inures to the benefit of such person's heirs, executors and administrators. The indemnification rights also include the right generally to be advanced expenses, subject to any undertaking required under Delaware General Corporation Law, and the right generally to recover expenses to enforce an indemnification claim or to defend specified suits with respect to advances of indemnification expenses.

The indemnification rights set forth above are not exclusive of any other right which an indemnified person may have or hereafter acquire under any statute, provision of the Registrant's amended and restated certificate of incorporation, the Registrant's amended and restated bylaws, agreement, vote of stockholders or disinterested directors, or otherwise.

See also the undertakings set out in response to Item 9 herein.

**Item 7. Exemption from Registration Claimed.**

Not applicable.

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**Item 8. Exhibits**

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| | |
|:---|:---|
| **Exhibit<br>Number** | **Description** |
| 4.1(1)  | [Specimen Common Stock certificate of the Registrant](http://www.sec.gov/Archives/edgar/data/1297184/000104746914005387/a2220360zex-4_1.htm) |
| 4.2(2) | [Amended and Restated 2015 Equity Incentive Plan and forms of agreement thereunder](https://www.sec.gov/Archives/edgar/data/1297184/000129718420000058/amph-20201103ex991aaec0d.htm)  |
| 5.1\*  | [Opinion of Wilson Sonsini Goodrich & Rosati, Professional Corporation](amph-20230301xex5d1.htm) |
| 23.1\*  | [Consent of Independent Registered Public Accounting Firm](amph-20230301xex23d1.htm) |
| 23.2\* | [Consent of Wilson Sonsini Goodrich & Rosati, Professional Corporation (contained in Exhibit 5.1 hereto)](amph-20230301xex5d1.htm) |
| 24.1\*  | [Power of Attorney (contained on signature pages hereto)](#powerofattorney) |
| 107\* | [Filing Fee Table](amph-20230301xexfilingfees.htm) |

---

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) Incorporated by reference to Exhibit 4.1 of the Registrant's Registration Statement on Form S-1/A (Registration No. 333-196097), filed with the Commission on June 5, 2014

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) Incorporated by reference to Exhibit 99.1 of the Registrant's Current Report on Form 8-K (File No. 001-36509), filed with the Commission on November 6, 2020

\* Filed herewith.

#### Item 9. Undertakings.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A. The undersigned Registrant hereby undertakes:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective Registration Statement; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) To include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement.

*Provided, however*, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed

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with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this Registration Statement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial *bona fide* offering thereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;B. The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial *bona fide* offering thereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;C. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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#### SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Rancho Cucamonga, State of California, on March 1, 2023.

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| | |
|:---|:---|
| **AMPHASTAR PHARMACEUTICALS, INC.** | **AMPHASTAR PHARMACEUTICALS, INC.** |
| By: | /s/ WILLIAM J. PETERS |
|  | William J. Peters |
|  | Chief Financial Officer |

---

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**POWER OF ATTORNEY**

*KNOW ALL PERSONS BY THESE PRESENTS*, that each person whose signature appears below hereby constitutes and appoints Jack Yongfeng Zhang, and William J. Peters, and each of them, as their true and lawful attorney-in-fact and agent with full power of substitution, for him or her in any and all capacities, to sign any and all amendments to this Registration Statement and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact, proxy and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully for all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact, proxy and agent, or his or her substitute, may lawfully do or cause to be done by virtue hereof. Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement and the Power of Attorney has been signed by the following persons in the capacities and on the dates indicated.

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| | | |
|:---|:---|:---|
| **Signature** | **Title** | **Date** |
| /s/ JACK Y. ZHANG | Chief Executive Officer, President, and Director (Principal Executive Officer) | March 1, 2023 |
| Jack Yongfeng Zhang | Chief Executive Officer, President, and Director (Principal Executive Officer) | March 1, 2023 |
| /s/ MARY Z. LUO | Chairman, Chief Operating Officer and Director | March 1, 2023 |
| Mary Z. Luo | Chairman, Chief Operating Officer and Director | March 1, 2023 |
| /s/ WILLIAM J. PETERS | Chief Financial Officer and Director (Principal<br>Financial and Accounting Officer) | March 1, 2023 |
| William J. Peters | Chief Financial Officer and Director (Principal<br>Financial and Accounting Officer) | March 1, 2023 |
| /s/ JACOB LIAWATIDEWI | Executive Vice President of Sales and Marketing, Corporate Administration Center, and Director | March 1, 2023 |
| Jacob Liawatidewi | Executive Vice President of Sales and Marketing, Corporate Administration Center, and Director | March 1, 2023 |
| /s/ GAYLE M. DEFLIN | Director | March 1, 2023 |
| Gayle M. Deflin | Director | March 1, 2023 |
| /s/ DIANE G. GERST | Director | March 1, 2023 |
| Diane G. Gerst | Director | March 1, 2023 |
| /s/ HOWARD LEE | Director | March 1, 2023 |
| Howard Lee | Director | March 1, 2023 |
| /s/ FLOYD PETERSEN | Director | March 1, 2023 |
| Floyd Petersen | Director | March 1, 2023 |
| /s/ RICHARD PRINS | Director | March 1, 2023 |
| Richard Prins | Director | March 1, 2023 |
| /s/ MICHAEL A. ZASLOFF | Director | March 1, 2023 |
| Michael A. Zasloff | Director | March 1, 2023 |

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## Exhibit 5.1

**Exhibit 5.1**

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| | |
|:---|:---|
|  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br>Palo Alto, California 94304-1050<br>: 650.493.9300<br>f: 650.493.6811<br>|
| &nbsp;&nbsp;![Graphic](amph-20230301xex5d1001.jpg)<br>| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Wilson Sonsini Goodrich & Rosati<br>Professional Corporation<br>650 Page Mill Road<br>Palo Alto, California 94304-1050<br>o: 650.493.9300<br>f: 650.493.6811<br>|

---

March 1, 2023

Amphastar Pharmaceuticals, Inc.

11570 6th Street

Rancho Cucamonga, California 91730

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| | |
|:---|:---|
| **Re:** | **Registration Statement on Form S-8** |

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Ladies and Gentlemen:

We have examined the Registration Statement on Form S-8 (the "**Registration Statement**") to be filed by Amphastar Pharmaceuticals, Inc., a Delaware corporation, with the Securities and Exchange Commission on or about the date hereof, in connection with the registration under the Securities Act of 1933, as amended, of 1,202,802 shares of common stock, par value $0.0001 per share (the **"Shares"**) reserved for issuance pursuant to the Amended and Restated 2015 Equity Incentive Plan (the **"Plan"**). As your legal counsel, we have reviewed the actions proposed to be taken by you in connection with the issuance and sale of the Shares to be issued under the Plan.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when issued and sold in the manner referred to in the Plan and pursuant to the agreements which accompany the Plan, will be legally and validly issued, fully paid and nonassessable.

We consent to the use of this opinion as an exhibit to the Registration Statement, and further consent to the use of our name wherever appearing in the Registration Statement and any amendments thereto.

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| |
|:---|
| Sincerely, |
| WILSON SONSINI GOODRICH & ROSATI |
| Professional Corporation<br>/s/ Wilson Sonsini Goodrich & Rosati, P.C. |

---

austin beijing boston brussels hong kong london los angeles new york palo alto<br>san diego san francisco seattle shanghai washington, dc wilmington, de

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## Exhibit 23.1

**Exhibit 23.1**

**Consent of Independent Registered Public Accounting Firm**

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the Amended and Restated 2015 Equity Incentive Plan of Amphastar Pharmaceuticals, Inc. of our reports dated March 1, 2023, with respect to the consolidated financial statements of Amphastar Pharmaceuticals, Inc. and the effectiveness of internal control over financial reporting of Amphastar Pharmaceuticals, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2022, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Irvine, California

March 1, 2023

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## Ex-Filing

**Exhibit 107**

**Calculation of Filing Fee Tables**

**Form S-8**

(Form Type)

**Amphastar Pharmaceuticals, Inc.** 

(Exact name of registrant as specified in its charter)

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| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
| &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** | &nbsp;&nbsp;**Table 1 – Newly Registered Securities** |
| &nbsp;&nbsp;**Security Type** | &nbsp;&nbsp;**Security Class Title** | &nbsp;&nbsp;**Fee Calculation Rule** | &nbsp;&nbsp;**Amount Registered(1)**<br>| &nbsp;&nbsp;**Proposed Maximum Offering Price Per Unit** | &nbsp;&nbsp;**Maximum Aggregate Offering Price** | &nbsp;&nbsp;**Fee Rate** | &nbsp;&nbsp;**Amount of Registration Fee** |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, $0.0001 par value per share, reserved for issuance pursuant to the Amended and Restated 2015 Equity Incentive Plan | &nbsp;&nbsp;Other | &nbsp;&nbsp;1202802(2) | &nbsp;&nbsp;$32.02(3) | &nbsp;&nbsp;$38513720.04 | &nbsp;&nbsp;$110.20 per $1,000,000 | &nbsp;&nbsp;$4244.21 |
| &nbsp;&nbsp;**Total Offering Amounts** | &nbsp;&nbsp;**Total Offering Amounts** | &nbsp;&nbsp;**Total Offering Amounts** | &nbsp;&nbsp;**Total Offering Amounts** |  | &nbsp;&nbsp;$38513720.04 |  | &nbsp;&nbsp;$4244.21 |
| &nbsp;&nbsp;**Total Fee Offsets(4)** | &nbsp;&nbsp;**Total Fee Offsets(4)** | &nbsp;&nbsp;**Total Fee Offsets(4)** | &nbsp;&nbsp;**Total Fee Offsets(4)** |  |  |  | &nbsp;&nbsp;– |
| &nbsp;&nbsp;**Net Fee Due** | &nbsp;&nbsp;**Net Fee Due** | &nbsp;&nbsp;**Net Fee Due** | &nbsp;&nbsp;**Net Fee Due** |  |  |  | &nbsp;&nbsp;**$4244.21** |

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) Pursuant to Rule 416(a) under the Securities Act of 1933, as amended , this registration statement shall also cover any additional shares of the Registrant's common stock that become issuable pursuant to the Registrant's Amended and Restated 2015 Equity Incentive Plan (the "2015 Plan") by reason of any dividend or other distribution (whether in the form of cash, shares of the Registrant's common stock, other securities, or other property), recapitalization, stock split, reorganization, merger, consolidation, split-up, spin-off, combination, repurchase, or exchange of shares of the Registrant's common stock or other securities of the Registrant, or other change in the corporate structure of the Registrant affecting the shares of the Registrant's common stock.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) Represents an automatic annual increase on January 1, 2023 to the number of shares of the Registrant's common stock reserved for issuance under the 2015 Plan, which annual increase is provided for in the 2015 Plan.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) Estimated in accordance with Rule 457(h) of the Securities Act solely for the purpose of calculating the registration fee on the basis of $32.02 per share, which is the average of the high and low prices of the Registrant's common stock as reported on the NASDAQ Global Select Market on February 22, 2023.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(4) The Registrant does not have any fee offsets.

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