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                                                                    Exhibit 10.6




                        ADDENDUM TO SUBLICENSE AGREEMENT

         THIS ADDENDUM to the Sublicense Agreement dated August 10, 2001 by and
between BioDelivery Sciences International, Inc. ("BDSI") and BioDelivery
Sciences, Inc. ("Agreement") and Tatton Technologies, LLC ("Tatton") is made and
entered into as of this 29th day of March 2002.

                              W I T N E S S E T H:

         WHEREAS, BioDelivery Sciences International, Inc., BioDelivery
Sciences, Inc. and Tatton entered into a Sublicense Agreement on August 10, 2001
which the parties wish to amend and modify as hereinafter set forth; and

         WHEREAS, BioDelivery Sciences, Inc. was subsequently merged into BDSI;
and

         WHEREAS, the parties wish to cause all royalty payments under this
Agreement to be calculated based upon Net Revenue as opposed to Net Profits in
order to eliminate the potential of regulatory, calculation, and accounting
concerns.

         NOW, THEREFORE, for good and valuable consideration in hand received,
including the mutual covenants and promises of the parties as set forth herein,
the parties mutually agree as follows:

         1. Paragraph 3 of the Sublicense Agreement of BDS into BDSI is hereby
deleted in its entirety and replaced with the following:

         "3. ROYALTY. Tatton agrees to pay BDSI a royalty equal to twelve
         percent (12%) of all net revenue (the "Net Revenue") received by Tatton
         from the sale of products which incorporate the BDSI Technology. For
         purposes hereof, Net Revenue, shall mean all revenue received by Tatton
         from the sale of products incorporating the BDSI Technology, less
         verifiable discounts. Net Revenue shall be computed in a consistent
         manner. Additionally, should Tatton enter into permitted licenses, as
         opposed to directly selling products incorporating the BDSI Technology,
         Tatton shall pay BDSI a royalty equal to thirty percent (30%) of all
         such royalties received by Tatton from the sublicensed products that
         include the BDSI Technology for permitted designated uses. Tatton shall
         not assign, sell, or otherwise sublicense its interest hereunder
         without the prior written consent of BDSI. Tatton shall pay all
         royalties hereunder on or before the 10th day of each month. All
         royalty payments shall be accompanied by a written report specifying
         revenues and discounts, and itemizing royalties received by Tatton
         relating to products which incorporate the BDSI Technology. BDSI shall
         have the right to inspect the books and records of Tatton at any
         reasonable time during normal business hours."

         2. All other terms and conditions of the Sublicense Agreement remain in
full force and effect.

         3. All references in this Addendum and in the Agreement to BioDelivery
Sciences, Inc. ("BDS") specifically mean and refer to BDSI subsequent to the
merger of BDS into BDSI.
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         IN WITNESS WHEREOF, the parties have set their hand and seal on the day
and year first above written.

BioDelivery Sciences International, Inc.         Tatton Technologies, LLC


By:     /s/ Raphael Mannino                      By:      /s/ Terry A. Fuller
     -----------------------------------            ----------------------------
     Raphael Mannino, PhD.                           Terry A. Fuller, PhD.
     Executive Vice President and                    President
     Chief Scientific Officer