**Exhibit
      31.1**





**CERTIFICATION
      OF CHIEF EXECUTIVE OFFICER**


**PURSUANT
      TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002 ***





I,  David
      Norris, Chief Executive Officer, certify that:





1.  I
      have
      reviewed this form 10-QSB for the quarter ended September 30, 2005 of Entropin,
      Inc.;





2. Based
      on my knowledge, this report does not contain any untrue statement of a material
      fact or omit to state a material fact necessary to make the statements made,
      in
      light of the circumstances under which such statements were made, not misleading
      with respect to the period covered by this quarterly report;





3.  Based
      on
      my knowledge, the financial statements, and other financial information included
      in this report, fairly present in all material respects the financial condition,
      results of operations and cash flows of the small business issuer as of, and
      for, the periods presented in this report;





4.
      The
      small business issuer’s other certifying officer(s) and I are responsible for
      establishing and maintaining disclosure controls and procedures (as defined
      in
      Exchange Act Rules 13a-15(e) and 15d-15(c)) for the small business issuer and
      we
      have:





(a)  Designed
      such disclosure controls and procedures, or caused such disclosure controls
      and
      procedures to be designed under our supervision, to ensure that material
      information relating to the small business issuer, including its consolidated
      subsidiaries, is made known to us by others within this entity, particularly
      during the period in which this report is being prepared;





(b)  Omitted;





(c)  Evaluated
      the effectiveness of the small business issuer’s disclosure controls and
      procedures and presented in this report our conclusions about the effectiveness
      of the disclosure controls and procedures, as of the end of the period covered
      by this report based on such evaluation; and





(d)  Disclosed in this quarterly report any change in the small business issuer’s
      internal control over financial reporting that occurred during the small
      business issuer’s most recent fiscal quarter (the small business issuer’s fourth
      fiscal quarter in the case of an annual report) that has materially affected,
      or
      is reasonably likely to materially affect, the small business issuer’s internal
      control over financial reporting; and





5.  The
      small
      business issuer’s other certifying officer(s) and I have disclosed, based on my
      most recent evaluation of internal control over financial reporting, to the
      small business issuer’s auditors and the audit committee of small business
      issuer’s board of directors (or persons performing the equivalent functions):





(a)  All
      significant deficiencies and material weaknesses in the design or operation
      of
      internal control over financial reporting which are reasonably likely to
      adversely affect the small business issuer’s ability to record, process,
      summarize and report financial information; and





(b)  Any
      fraud, whether or not material, that involves management or other employees
      who
      have a significant role in the small business issuer’s internal control over
      financial reporting.





Date:
      November 15, 2005




/s/
                David
                NorrisDavid
                NorrisChief
                Executive Officer





*The
      introductory portion of paragraph 4 of the Section 302 certification that refers
      to the certifying offices’ responsibility for establishing and maintaining
      internal control over financial reporting for the company, as well as paragraph
      4(b), have been omitted in accordance with Release No. 33-8545 (March 2, 2005)
      because the compliance period has been extended for small business issuers
      until
      the first fiscal year ending on or after July 15, 2006.





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