EXHIBIT C JOINT FILING AGREEMENT

                                                             Page 26 of 50 Pages

                                    EXHIBIT C

                             JOINT FILING AGREEMENT

               The  undersigned  hereby agree that the statement on Schedule 13D
with respect to the Common Stock of Triangle  Pharmaceuticals,  Inc.  dated June
16, 1997 is, and any amendments  thereto signed by each of the undersigned shall
be,  filed  on  behalf  of each of us  pursuant  to and in  accordance  with the
provisions of Rule 13d-1(f) under the Securities Exchange Act of 1934.

Date:  June 16, 1997

                                             QUANTUM INDUSTRIAL PARTNERS LDC


                                             By:  /S/ XXXX X. XXXXXX
                                                  -----------------------------
                                                  Xxxx X. Xxxxxx
                                                  Attorney-in-Fact


                                             QIH MANAGEMENT INVESTOR, L.P.

                                             By:  QIH Management, Inc.,
                                                  its General Partner


                                                  By:  /S/ XXXX X. XXXXXX
                                                       ------------------------
                                                       Xxxx X. Xxxxxx
                                                       Vice President


                                             QIH MANAGEMENT, INC.


                                             By:  /S/ XXXX X. XXXXXX
                                                  -----------------------------
                                                  Xxxx X. Xxxxxx
                                                  Vice President


                                             XXXXX FUND MANAGEMENT LLC


                                             By:  /S/ XXXX X. XXXXXX
                                                  -----------------------------
                                                  Xxxx X. Xxxxxx
                                                  Managing Director






                                                             Page 27 of 50 Pages

                                             XXXXXX XXXXX


                                             By:  /S/ XXXX X. XXXXXX
                                                  -----------------------------
                                                  Xxxx X. Xxxxxx
                                                  Attorney-in-Fact


                                             XXXXXXX X. XXXXXXXXXXXXX


                                             By:  /S/ XXXX X. XXXXXX
                                                  -----------------------------
                                                  Xxxx X. Xxxxxx
                                                  Attorney-in-Fact


                                             DUQUESNE CAPITAL MANAGEMENT, L.L.C.


                                             By:  /S/ XXXXXX XXXXXX
                                                  -----------------------------
                                                  Xxxxxx Xxxxxx
                                                  Managing Director