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 * MPM BioVentures IV QP LP   2. Issuer Name and Ticker or Trading Symbol Pacira Pharmaceuticals, Inc. [PCRX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MPM ASSET MANAGEMENT, 200 CLARENDON STREET, 54TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 02/08/2011 (Street) BOSTON, MA 02116 4. If Amendment, Date 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 (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 02/08/2012   C   1,487,680 (1) A (2) 1,580,660 I See footnote (3) Common Stock 02/08/2012   C   712,567 (7) A (7) 2,293,227 I See footnote (8) Common Stock 02/08/2012   P(9)   267,857 (10) A $ 7 2,561,084 I See footnote (11) Common Stock 02/08/2012   P   267,857 (12) A $ 7 2,828,941 I See footnote (13)

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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

Series A Convertible Preferred Stock

(2)

02/08/2012

C

1,487,680

(4)

(4)

Common Stock

1,487,680 (5)

$ 0

0

I

See footnote (6)

Convertible Promissory Note

$ 13.44

02/08/2012

C

712,567

(7)

(7)

Common Stock

712,567 (7)

$ 0

0

I

See footnote (6)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MPM BioVentures IV QP LP C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BioVentures IV GP LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BioVentures IV LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM Asset Management Investors BV4 LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BioVentures IV GmbH & Co. Beteiligungs KG C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
DOMBKOWSKI ASHLEY L C/O MPM ASSET MANAGEMENT 601 GATEWAY BLVD., SUITE 350 SOUTH SAN FRANCISCO, CA 94080		X
Vander Vort John C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
Scopa James Paul C/O MPM ASSET MANAGEMENT 601 GATEWAY BLVD., SUITE 350 SOUTH SAN FRANCISCO, CA 94080		X
St Peter Steven C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
Greene William C/O MPM ASSET MANAGEMENT 601 GATEWAY BLVD., SUITE 350 SOUTH SAN FRANCISCO, CA 94080		X

Signatures

By Vaughn Kailian, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC, the general partner of MPM BioVentures IV-QP, L.P. /s/ Vaughn Kailian		02/10/2011
**Signature of Reporting Person		Date
By Vaughn Kailian, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC /s/ Vaughn Kailian		02/10/2011
**Signature of Reporting Person		Date
By Vaughn Kailian, member of MPM BioVentures IV LLC /s/ Vaughn Kailian		02/10/2011
**Signature of Reporting Person		Date
By Vaughn Kailian, member of MPM BioVentures IV LLC, the manager of MPM Asset Management Investors BV4 LLC /s/ Vaughn Kailian		02/10/2011
**Signature of Reporting Person		Date
By Vaughn M. Kailian, member of MPM BioVentures IV LLC, the managing member of MPM BioVentures IV GP LLC, the managing limited partner of MPM BioVentures IV GmbH & Co. Beteiligungs KG /s/ Vaughn M. Kailian		02/10/2011
**Signature of Reporting Person		Date
/s/ Ashley Dombkowski		02/10/2011
**Signature of Reporting Person		Date
/s/ John Vander Vort		02/10/2011
**Signature of Reporting Person		Date
/s/ James Paul Scopa		02/10/2011
**Signature of Reporting Person		Date
/s/ Steven St. Peter		02/10/2011
**Signature of Reporting Person		Date
/s/ William Greene		02/10/2011
**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)	Represents shares of Common Stock acquired upon the automatic conversion of Series A Preferred Stock upon the closing of the Issuer's initial public offering of Common Stock.
(2)	Each share of Series A Convertible Preferred Stock converted into 1 share of Common Stock.
(3)	The shares are held as follows: 1,481,459 by MPM BioVentures IV-QP, L.P. ("BV IV QP"), 57,074 by MPM BioVentures IV GmbH & Co. Beteiligungs KG ("BV IV KG") and 42,127 by MPM Asset Management Investors BV4 LLC ("AM BV4"). MPM BioVentures IV GP LLC and MPM BioVentures IV LLC ("BV LLC") are the direct and indirect general partners of BV IV QP and BV IV KG and BV LLC is the manager of AM BV4. Vaughn M. Kailian, Ansbert Gadicke, Luke Evnin, Steven St. Peter, William Greene, James Paul Scopa, Ashley Dombkowski and John Vander Vort are the members of the general partner of BV IV QP, BV IV KG and members of AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his, her or its respective pecuniary interest therein.
(4)	These securities are preferred stock of the Issuer and did not have an expiration date. Prior to the Issuer's initial public offering, the securities were convertible at any time at the election of the holder. The securities automatically converted into shares of Common Stock upon the closing of the Issuer's initial public offering of Common Stock.
(5)	The shares were held as follows: 1,394,315 by BV IV QP, 53,717 by BV IV KG and 39,648 by AM BV4.
(6)	No securities owned.
(7)	The Notes were held in the principal amount as follows: $8,200,858 by BV IV QP, $315,945 by BV IV KG and $233,196 by AM BV4. The principal and accrued interest on the Notes automatically converted into the following shares of Common Stock upon the closing of the Issuer's initial public offering of Common Stock: 667,848 by BV IV QP, 25,729 by BV IV KG and 18,990 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his, her or its respective pecuniary interest therein.
(8)	The shares are held as follows: 2,149,307 by BV IV QP, 82,803 by BV IV KG and 61,117 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his, her or its respective pecuniary interest therein.
(9)	The Common Stock was acquired upon conversion of convertible promissory notes exempt from the definition of a derivative security because the conversion price did not become fixed until automatic conversion at the time of the closing of the Issuer's initial public offering of Common Stock.
(10)	Represents the following shares of Common Stock acquired upon the conversion of convertible promissory notes issued in December 2010: 251,047 by BV IV QP, 9,672 by BV IV KG and 7,138 by AM BV4. The outstanding principal amount was automatically converted into shares of Common Stock of the Issuer upon the consummation of an initial public offering of the Issuer's Common Stock at a conversion price equal to $7.00, which was the initial public offering price per share.
(11)	The shares are held as follows: 2,400,354 by BV IV QP, 92,475 by BV IV KG and 68,255 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his, her or its respective pecuniary interest therein.
(12)	The shares were purchased as follows: 251,046 by BV IV QP, 9,672 by BV IV KG and 7,139 by AM BV4.
(13)	The shares are held as follows: 2,651,400 by BV IV QP, 102,147 by BV IV KG and 75,394 by AM BV4. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his, her or its respective pecuniary interest therein.
Remarks: See Form 4 for Vaughan Kailian for additional members of this joint filing.

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