FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * STACK DAVID M   2. Issuer Name and Ticker or Trading Symbol Pacira Pharmaceuticals, Inc. [PCRX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO and Chairman (Last) (First) (Middle) C/O PACIRA PHARMACEUTICALS, INC., 5 SYLVAN WAY, SUITE 300 3. Date of Earliest Transaction (Month/Day/Year) 01/10/2018 (Street) PARSIPPANY, NJ 07054 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) 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 01/10/2018   M(1)   28,885 A $ 1.61 129,331 (2) D   Common Stock 01/10/2018   S(1)   23,372 D $ 39.96 (3) 105,959 D   Common Stock 01/10/2018   S(1)   4,628 D $ 41.03 (4) 101,331 D   Common Stock 01/10/2018   S(1)   885 D $ 41.97 (5) 100,446 D   Common Stock               18,596 I By Stack Schroon Mohawk FLP (6) Common Stock               1,208 I By LCK Investment LLC (6)

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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 Underlying Securities (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 of Derivative Security: 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

Stock Option (Right to Buy)

$ 1.61

01/10/2018

M

28,885

(7)

09/02/2020

Common Stock

28,885

$ 0

83,190

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
STACK DAVID M C/O PACIRA PHARMACEUTICALS, INC. 5 SYLVAN WAY, SUITE 300 PARSIPPANY, NJ 07054	X		CEO and Chairman

Signatures

/s/ Kristen Williams, Attorney-in-Fact		01/12/2018
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The option exercise and sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934.
(2)	Includes 167 shares of common stock acquired under the issuer's employee stock purchase plan in December 2017.
(3)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $39.625 to $40.60, inclusive. The reporting person undertakes to provide to the issuer, any shareholder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes 2, 3 and 4.
(4)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $40.65 to $41.55, inclusive.
(5)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $41.70 to $42.25, inclusive.
(6)	Mr. Stack is the general partner of Stack Schroon Mohawk FLP. Mr. Stack and his wife are the owners of LCK Investment LLC.
(7)	The option vested as to 50% of the option shares on February 2, 2011, 19,378 option shares vested on February 3, 2011, and the remaining option shares vested in successive monthly installments for the subsequent 19 months.

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