SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                 SCHEDULE 13G
                                (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)

                                  Amendment No.

                                  ZONAGEN, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)


--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    98975L108
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                DECEMBER 31, 2005
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)

     Check the  appropriate  box to  designate  the rule  pursuant to which this
Schedule is filed:

          |_|  Rule 13d-1(b)

          |X|  Rule 13d-1(c)

          |_|  Rule 13d-1(d)

----------
(1)  The  remainder  of this  cover  page  shall be filled  out for a  reporting
     person's  initial  filing on this form with respect to the subject class of
     securities,  and for any subsequent amendment containing  information which
     would alter the disclosures provided in a prior cover page.

     The  information  required in the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 or otherwise  subject to the  liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).



CUSIP No. 98975L108                    13G                    Page 2 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Partners, L.P.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           155,485
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         155,485
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     155,485
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     1.54%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 3 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Partners II, L.P.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           5,219
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         5,219
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     5,219
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     .05%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 4 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Offshore Fund, Ltd.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     British Virgin Islands
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           25,780
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         25,780
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     25,780
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     .26%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     CO
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 5 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Offshore Fund II, Ltd.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     British Virgin Islands
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           631,349
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         631,349
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     631,349
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     6.26%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     CO
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 6 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Asset Management, L.L.C.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Massachusetts
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           160,356
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         160,356
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     160,356

(Reporting person disclaims beneficial ownership of shares held by ProMed
Partners, L.P. and ProMed Partners II, L.P. which represent the interests of
other partners of these entities.)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     1.59%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     IA
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 7 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     ProMed Management, Inc.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Massachusetts
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           657,129
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         657,129
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     657,129

(Reporting person disclaims beneficial ownership of shares held by ProMed
Offshore Fund, Ltd. and ProMed OffShore Fund II, Ltd. which represent the
interests of the shareholders of ProMed Offshore Fund, Ltd. and ProMed Offshore
Fund II, Ltd.)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     6.52%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     IA
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 98975L108                    13G                    Page 8 of 13 Pages

--------------------------------------------------------------------------------
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Barry Kurokawa
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  |X|
                                                                 (b)  |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY

--------------------------------------------------------------------------------
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Massachusetts
--------------------------------------------------------------------------------
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           26,000
               -----------------------------------------------------------------
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          817,485
               -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         26,000
               -----------------------------------------------------------------
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            817,485
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     843,485

(Reporting person disclaims beneficial ownership of shares held by ProMed
Offshore Fund, Ltd. and ProMed OffShore Fund II, Ltd. which represent the
interests of the shareholders of ProMed Offshore Fund, Ltd. and ProMed Offshore
Fund II, Ltd.)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     8.37%
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON*

     IA
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



                                                              Page 9 of 13 Pages

Item 1(a).  Name of Issuer:

Zonagen, Inc.

--------------------------------------------------------------------------------

Item 1(b).  Address of Issuer's Principal Executive Offices:

2408 Timberloch Place, Suite B-1, Woodlands, TX 77380

--------------------------------------------------------------------------------

Item 2(a).  Name of Person Filing:

ProMed Partners, L.P., ProMed Partners II, L.P., ProMed Offshore Fund, Ltd.,
ProMed OffShore Fund II, Ltd., ProMed Management, Inc., and ProMed Asset
Management, L.L.C., and Barry Kurokawa

--------------------------------------------------------------------------------

Item 2(b).  Address of Principal Business Office, or if None, Residence:

125 Cambridgepark Drive, Cambridge, MA 02140

--------------------------------------------------------------------------------

Item 2(c).  Citizenship:

See pages 2,3,4,5,6,7 and 8

--------------------------------------------------------------------------------

Item 2(d).  Title of Class of Securities:

Common Stock

--------------------------------------------------------------------------------

Item 2(e).  CUSIP Number:

98975L108

--------------------------------------------------------------------------------

Item 3.     If This Statement  is Filed  Pursuant to  Rule 13d-1(b), or 13d-2(b)
            or (c), Check Whether the Person Filing is a:

     (a)  |_|  Broker or dealer registered under Section 15 of the Exchange Act.

     (b)  |_|  Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c)  |_|  Insurance  company as defined in Section 3(a)(19) of the Exchange
               Act.

     (d)  |_|  Investment  company  registered under Section 8 of the Investment
               Company Act.

     (e)  |_|  An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

     (f)  |_|  An employee  benefit plan or endowment  fund in  accordance  with
               Rule 13d-1(b)(1)(ii)(F);

     (g)  |_|  A parent  holding  company or control  person in accordance  with
               Rule 13d-1(b)(1)(ii)(G);

     (h)  |_|  A savings  association  as defined in Section 3(b) of the Federal
               Deposit Insurance Act;

     (i)  |_|  A  church  plan  that  is  excluded  from  the  definition  of an
               investment  company  under  Section  3(c)(14)  of the  Investment
               Company Act;

     (j)  |_|  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

     If this statement is filed pursuant to Rule 13d-1(c), check this box |X|



                                                             Page 10 of 13 Pages

Item 4.  Ownership.

     Provide  the  following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:

          See pages 2,3,4,5,6,7 and 8

     (b)  Percent of class:

          See pages 2,3,4,5,6,7 and 8

     (c)  Number of shares as to which such person has:

          (i)   Sole power to vote or to direct the vote

                See pages 2,3,4,5,6,7 and 8

          (ii)  Shared power to vote or to direct the vote

                See pages 2,3,4,5,6,7 and 8

          (iii) Sole power to dispose or to direct the disposition of

                See pages 2,3,4,5,6,7 and 8

          (iv)  Shared power to dispose or to direct the disposition of

                See pages 2,3,4,5,6,7 and 8

--------------------------------------------------------------------------------

Item 5.  Ownership of Five Percent or Less of a Class.

         Not Applicable

--------------------------------------------------------------------------------

Item 6.  Ownership of More Than Five Percent on Behalf of Another Person.

         Not Applicable

--------------------------------------------------------------------------------

Item 7.  Identification and  Classification of the Subsidiary Which Acquired the
         Security  Being  Reported on by the Parent  Holding  Company.

         Not Applicable

--------------------------------------------------------------------------------

Item 8.  Identification  and  Classification  of Members of the Group.

         See "Exhibit A" attached hereto and pages 2, 3, 4, 5, 6, 7 and 8

--------------------------------------------------------------------------------

Item 9.  Notice of Dissolution of Group.

         Not Applicable

--------------------------------------------------------------------------------

Item 10.  Certifications.

     (a)  The  following  certification  shall be included if the  statement  is
          filed pursuant to Rule 13d-1(b):

          "By signing  below I certify  that,  to the best of my  knowledge  and
          belief, the securities referred to above were acquired and are held in
          the ordinary course of business and were not acquired and not held for
          the  purpose  of or with the effect of  changing  or  influencing  the
          control of the issuer of the  securities and were not acquired and are
          not held in  connection  with or as a participant  in any  transaction
          having such purpose or effect."

     (b)  The  following  certification  shall be included if the  statement  is
          filed pursuant to Rule 13d-1(c):

          "By signing  below I certify  that,  to the best of my  knowledge  and
          belief, the securities referred to above were not acquired and are not
          held for the purpose of or with the effect of changing or  influencing
          the control of the issuer of the  securities and were not acquired and
          are not held in connection with or as a participant in any transaction
          having such purpose or effect."



                                                             Page 11 of 13 Pages

                                    SIGNATURE

     After  reasonable  inquiry and to the best of my  knowledge  and belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.

                                                    June 7, 2005
                                        ----------------------------------------
                                                        (Date)


                                             /s/ David B. Musket
                                        ----------------------------------------
                                                      (Signature)

                                             David B. Musket,
                                             President of Managing Member
                                             of the General Partner
                                        ----------------------------------------
                                                      (Name/Title)

Note. Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7(b) for other
parties for whom copies are to be sent.

Attention.  Intentional  misstatements  or omissions of fact constitute  federal
criminal violations (see 18 U.S.C. 1001).



Schedule 13 G                                                      Page 12 of 13

CUSIP No. 98975L108

                                Index to Exhibits

Exhibit                                                                 Page No.
-------                                                                 --------

Exhibit A -- Joint Filing Agreement, dated June 7, 2005                    12



Schedule 13 G                                                      Page 13 of 13

CUSIP No. 98975L108

EXHIBIT A

                             JOINT FILING AGREEMENT

ProMed Partners, L.P., ProMed Partners II, L.P., ProMed Offshore Fund, Ltd.,
ProMed Offshore Fund II, Ltd. ProMed Management, Inc., and ProMed Asset
Management, LLC, each hereby agrees that the Schedule 13G to which this Exhibit
is attached and any amendments thereto relating to the acquisition of Shares of
Common Stock of Orion Acquisition Corp.is filed jointly on behalf of each such
person.

Dated: June 7, 2005

                                      PROMED PARTNERS, L.P.

                                      By: ProMed Asset Management, LLC
                                               its General Partner
                                      By: DBM Corporate Consulting Group, Ltd,
                                               a Managing Member


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               Director


                                      PROMED PARTNERS, II, L.P.

                                      By: ProMed Asset Management, LLC
                                               its General Partner
                                      By: DBM Corporate Consulting Group, Ltd.
                                               a Managing Member


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               Director


                                      PROMED OFFSHORE FUND, LTD.


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               Director


                                      PROMED OFFSHORE FUND II, LTD.


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               Director


                                      PROMED MANAGEMENT, INC.


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               President


                                      PROMED ASSET MANAGEMENT, LLC

                                      By: DBM Corporate Consulting Group, Ltd.
                                               A Managing Member


                                      By:      /s/ David B. Musket
                                         --------------------------------------
                                               David B. Musket
                                               President


                                      Barry Kurokawa

                                      By:      /s/ Barry Kurokawa
                                         --------------------------------------