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                                                                     EXHIBIT 3.3

                           CERTIFICATE OF AMENDMENT OF
              AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF
                       INTRABIOTICS PHARMACEUTICALS, INC.

     IntraBiotics Pharmaceuticals, Inc., a corporation organized and existing
under and by virtue of the General Corporation Law of the State of Delaware (the
"Corporation"), does hereby certify:

     FIRST: The name of the Corporation is IntraBiotics Pharmaceuticals, Inc.

     SECOND: The Certificate of Incorporation of the Corporation was originally
filed with the Secretary of State of the State of Delaware on January 19, 1994.

     THIRD: The Board of Directors of the Corporation, acting in accordance with
the provisions of Sections 141 and 242 of the General Corporation Law of the
State of Delaware, adopted resolutions amending its Amended and Restated
Certificate of Incorporation as follows:

     The first paragraph of Article IV shall be amended and restated to read in
its entirety as follows:

                                      "IV.

          "A. This Corporation is authorized to issue two classes of stock to be
     designated, respectively, "Common Stock" and "Preferred Stock." The total
     number of shares which the corporation is authorized to issue is
     Seventy-Five Million (75,000,000) shares. Seventy Million (70,000,000)
     shares shall be Common Stock, each having a par value of one-tenth of one
     cent ($.001). Five Million (5,000,000) shares shall be Preferred Stock,
     each having a par value of one-tenth of one cent ($.001). Effective as of
     5:00 p.m., Eastern time, on the date this Certificate of Amendment of the
     Amended and Restated Certificate of Incorporation is filed with the
     Secretary of State of the State of Delaware, each twelve (12) shares of the
     Corporation's Common Stock, par value $.001 per share, issued and
     outstanding shall, automatically and without any action on the part of the
     respective holders thereof, be combined and converted into one (1) share of
     Common Stock, par value $.001 per share, of the Corporation. No fractional
     shares shall be issued and, in lieu thereof, any holder of less than one
     share of Common Stock shall be entitled to receive cash for such holder's
     fractional share based upon the closing sales price of the Corporation's
     Common Stock as reported on the Nasdaq National Market as of the date this
     Certificate of Amendment is filed with the Secretary of State of the State
     of Delaware."

     FOURTH: Thereafter, pursuant to a resolution of the Board of Directors,
this Certificate of Amendment was submitted to the stockholders of the
Corporation for approval, and was duly adopted in accordance with the provisions
of Section 242 of the General Corporation Law of the State of Delaware. The
total number of outstanding shares entitled to vote or consent to this
Certificate of Amendment was 39,231,351 shares of Common Stock. A majority of
the outstanding shares of Common Stock, voting together as a single class, voted
in favor of this Certificate of Amendment of the Amended and Restated
Certificate of Incorporation. The vote required was a majority of the
outstanding shares of Common Stock, voting together as a single class.

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     IN WITNESS WHEREOF, IntraBiotics Pharmaceuticals, Inc. has caused this
Certificate of Amendment to be signed by its President and Chief Executive
Officer on this 10th day of April, 2003.

                                  INTRABIOTICS PHARMACEUTICALS, INC.

                                  By: /s/ Henry J. Fuchs
                                      -------------------------------------
                                      Henry J. Fuchs, M.D.
                                      President and Chief Executive Officer

                                       2.