EXHIBIT 5.1

                   BRENMAN BROMBERG & TENENBAUM, P.C.
                            ATTORNEYS AT LAW

                         MELLON FINANCIAL CENTER
                               SUITE 1001
                           1775 SHERMAN STREET                  FACSIMILE
 TELEPHONE             DENVER, COLORADO 80203-4314           303-839-1633
303-894-0234                                                 303-830-8890


                            ________________, 2000

Board of Directors
Entropin, Inc.
45926 Oasis Street
Indio, CA 92201

RE:  ENTROPIN, INC.
     REGISTRATION STATEMENT ON FORM SB-2

Gentlemen:

     We have acted as counsel to Entropin, Inc., a Colorado corporation
(the "Company"), in connection with the preparation and filing with the
U.S. Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Act"), the Company's registration
statement on Form SB-2 (the "Registration Statement").  The Registration
Statement relates to the registration under the Act of:  (i) 2,500,000
shares of Common Stock (the "Shares"); (ii) 2,500,000 Warrants each to
purchase one share of Common Stock (the "Warrants"); and, (iii) and the
2,500,000 shares of Common Stock underlying the Warrants (the "Underlying
Shares").

     In rendering this opinion, we have reviewed the Registration
Statement, as well as a copy of the Company's articles of incorporation and
bylaws, each as amended to date.  We have also reviewed such documents and
such statutes, rules and judicial precedents as we have deemed necessary
for the opinions expressed herein.

     In rendering this opinion, we have assumed the genuineness of all
signatures, the legal capacity of natural persons, the authenticity of
documents submitted to us as originals, the conformity to original
documents of documents submitted to us as certified or photostatic copies,
and the authenticity of originals of such photostatic copies.

     Based upon and in reliance upon the foregoing, and subject to the
qualifications and limitations herein set forth, we are of the opinion that
the Shares and Warrants have been duly and validly authorized and issued,
and that the Underlying Shares, when issued for the consideration and in
the manner contemplated by the Registration Statement, will be validly
issued, fully paid and nonassessable.



Board of Directors
Entropin, Inc.
_________________, 2000

     The opinion set forth in this letter is limited by, subject to and
based on the following:

     1.   We are admitted to practice before the Bar of the State
          of Colorado and are not admitted to practice in any
          other jurisdiction.

     2.   The foregoing opinion is limited in all respects to the
          laws of the State of Colorado and applicable federal
          securities laws of the United States.

     We consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement.

     This opinion may not be used, circulated, quoted or otherwise referred
to for any other purpose without prior written consent and may not be
relied upon by any person or entity other than the Company and its
successors and assigns.  This opinion is based upon our knowledge of law
and facts as of this date.  We assume no duty to communicate to you with
respect to any matter which comes to our attention hereafter.

                              Very truly yours,



                              /s/ Brenman Bromberg & Tenenbaum, P.C.