**E** **XHIBIT
      31.1**


**SECTION
      302 CERTIFICATION**






I,
      David
      L. Norris, certify that:




1.  I
      have
      reviewed this form 10-KSB for the fiscal year ended December 31, 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 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.  I
      am
      responsible for establishing and maintaining disclosure controls and procedures
      (as defined in Exchange Act Rules 13a-15(e) and 15d-15 (e)) for the small
      business issuer and 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 those entities, 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 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.  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
      the 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: April
                10, 2006
              By:
              /s/Name:
                David L. NorrisTitle:
                President and Chief Executive Officer
  *The
      introductory portion of paragraph 4 of the Section 302 certification that refers
      to the certifying officers’ 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 Nos. 33-8618 and 34-52492
      (September 22, 2005) because the compliance period has been extended for small
      business issuers until the first fiscal year ending on or after July 15,
      2007.




EXHIBIT
          31.1-1