Exhibit 4.2

[FACE OF CERTIFICATE]

API

INCORPORATED UNDER THE
LAWS OF THE STATE OF DELAWARE

[LOGO]

CUSIP 00202H 10 8

SEE REVERSE FOR CERTAIN DEFINITIONS

This Certifies that

is the record holder of

FULLY PAID AND NONASSESSABLE SHARES
OF COMMON STOCK, $0.001 PAR VALUE, OF

APP Pharmaceuticals, Inc.

transferable on the books of the Corporation by the holder hereof in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid until countersigned by the Transfer Agent and
registered by the Registrar.

WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers.

Dated:

[SIGNATURE]

CHIEF FINANCIAL OFFICER

[SEAL]

[SIGNATURE]

CHIEF EXECUTIVE OFFICER & CHAIRMAN

COUNTERSIGNED AND REGISTERED:

AMERICAN STOCK TRANSFER & TRUST
COMPANY

(NEW YORK, NEW YORK)

TRANSFER AGENT
AND REGISTRAR

BY

AUTHORIZED OFFICER



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[REVERSE OF CERTIFICATE]

The Corporation shall furnish without charge to each stockholder who so requests a statement of the powers, designations, preferences and relative, participating, optional, or other special rights of each class of stock of the Corporation
or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights. Such requests shall be made to the Corporations Secretary at the principal office of the Corporation.

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to
applicable laws or regulations:

TEN COM  as tenants in common

TEN ENT  as tenants by the entireties

JT TEN  as joint tenants with right of

survivorship and not as tenants

in common



|                              |  |        |  |           |  |         |  | 
|----------------------------- |  | ------ |  | --------- |  | ------- |  | 
|UNIF GIFT MIN ACT            |  |        |  | Custodian |  |         |  | 
|                              |  | (Cust) |  |           |  | (Minor) |  | 
|under Uniform Gifts to Minors |  |        |  |          

|    |  |         |  |  |  |  |  | 
|--- |  | ------- |  |  |  |  |  | 
|Act |  |         |  |  |  |  |  | 
|    |  | (State) |  |  |  |  |  | 

|                   |  |                         |  |                       |  | 
|------------------ |  | ----------------------- |  | --------------------- |  | 
|UNIF TRF MIN ACT  |  |                         |  | Custodian (until age) |  | 
|                   |  | (Cust)                  |  |                       |  | 
|                   |  | under Uniform Transfers |  |                       |  | 
|(Minor)            |  |                         |  |                       |  | 

|              |  |         |  |  |  | 
|------------- |  | ------- |  |  |  | 
|to Minors Act |  |         |  |  |  | 
|              |  | (State) |  |  |  | 

Additional abbreviations may also be used though not in the above list.

For Value Received,
hereby sell(s), assign(s) and transfer(s) unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

Shares of the common stock represented by the within certificate, and do hereby irrevocably constitute and appoint

Attorney to transfer the said
stock on the books of the within named corporation with full power of substitution in the premises.



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Dated

X

X

NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS
WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE

WHATEVER.

Signature(s) Guaranteed

By

THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN
APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.