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EXHIBIT 4.11

                               FIRST AMENDMENT TO
                          REGISTRATION RIGHTS AGREEMENT

         THIS FIRST AMENDMENT TO REGISTRATION RIGHTS AGREEMENT (this "First
Amendment") is made and effective as of the effective date set forth on the
signature page hereof, by and between BIOGAN INTERNATIONAL, INC., a Delaware
corporation (the "Company"), and THOMSON KERNAGHAN & CO., LIMITED, a Canadian
limited liability company (the "Investor").

                                 R E C I T A L S

         A. The Company entered into a Registration Rights Agreement dated March
8, 2000 (the "RRA") with CALP II, a Bermuda limited partnership ("CALP II"), and
Carbon Mesa Partners, LLC, a Nevada limited liability company ("Carbon Mesa").

         B. On June 1, 2000, CALP II assigned all of its right, title and
interest in the RRA to the Investor.

         C. The Company has failed to meet some of its obligations under the
terms of the RRA and is, therefore, liable for certain Late Filing Penalties and
Late Effective Date Penalties (as those terms are defined in Section 2(b) of the
RRA). As of the date hereof, the aggregate amount of penalties claimed by the
Investor to be due from the Company in connection with such failures is $956,450
(the "Outstanding Penalties").

         D. The Company is also in default under the terms of the 8% Secured
Convertible Debenture Due February 28, 2002 issued by the Company to CALP II
(and later assigned by CALP II to Investor) on or about March 30, 2000 (the
"Debenture"). Concurrently with the execution of this First Amendment, the
Company and the Investor are entering into the First Amendment to 8% Secured
Convertible Debenture due February 28, 2002 ("Debenture Amendment") in
connection with such defaults.

         E. The Company and the Investor desire to settle all of their
disagreements concerning the Company's defaults under the terms of the RRA and
the Debenture, and to amend the RRA on the terms and conditions set forth
herein.

                                A G R E E M E N T

         NOW, THEREFORE, for and in consideration of the premises and the mutual
covenants hereinafter set forth, the parties hereto do hereby agree as follows:

         1. PAYMENT BY COMPANY TO INVESTOR.

                  (a) The Debenture Amendment shall amend the Debenture to
         increase the principal amount by Six Hundred Fifty Thousand Dollars
         ($650,000) (the "Settlement Amount"), as full settlement for the
         outstanding defaults and Outstanding Penalties under the RRA. The
         Settlement Amount shall be payable according to the terms and
         conditions of the Debenture Amendment, and the conversion price for the
         Settlement Amount, as calculated under the terms of the Debenture
         Amendment, shall not be less than $0.025 per share.

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                  (b) On or before September 30, 2001, the Company shall pay to
         the Investor Six Hundred Ninety Dollars ($690) as reimbursement for
         fees associated with the lapsed letter of credit.

         2. WAIVER OF DEFAULTS BY INVESTOR.

                  (a) Section 2(a) of the RRA is hereby amended to delete the
         30-day and 120-day time period requirements contained in Section 2(a)
         relating to the filing and effectiveness of a registration statement
         covering the Registrable Securities (as defined in the RRA).

                  (b) Investor hereby waives all rights to enforcement and any
         remedies under the RRA including, but not limited to, rights to collect
         the Outstanding Penalties, pursuant to Section 2(b) of the RRA that
         existed or may exist prior to, as of and after the date of this First
         Amendment. Section 2(b) of the RRA is hereby amended and restated to
         read in its entirety as follows:

                           "(b) PAYMENTS BY THE COMPANY.

                                    (i) On or prior to November 30, 2001, the
                  Company shall (x) file with the Securities and Exchange
                  Commission (the "SEC") any and all securities filings required
                  to be filed with the SEC by the Company under the Securities
                  Exchange Act of 1934, as amended (the "1934 Act"), including,
                  but not limited to, any and all filings that were or are
                  required to be filed by the Company with the SEC under the
                  1934 Act prior to the date hereof (collectively, the
                  "Securities Filings") and (y) secure and maintain exchange or
                  NASD's OTC Electronic Bulletin Board authorization and
                  quotation for its common stock ("Relisting").

                                    (ii) On or prior to January 31, 2002 (the
                  "Required Filing Date"), the Company shall file a registration
                  statement with SEC on Form SB-2 (the "Registration
                  Statement"), which Registration Statement shall include, inter
                  alia, the registration of (w) the 13,200,000 shares of the
                  Company's common stock issuable to the Investor upon
                  conversion of the 1,100 shares of the Company's Series A
                  Convertible Preferred Stock held by the Investor (which shall
                  be converted as soon as reasonably possible in accordance with
                  the terms of the Certificate of Designation covering the
                  Company's Series A Convertible Preferred Stock), (x) the
                  2,500,000 shares of the Company's common stock issued to the
                  Investor pursuant to the Debenture Amendment, (y) the Warrant
                  Shares, and (z) the Conversion Shares. The Registration
                  Statement also shall cover such indeterminate number of
                  additional shares of common stock as may necessary to prevent
                  dilution resulting from stock splits or stock dividends.

                                    (iii) If the Company fails to comply with
                  its obligations under Section 2(b)(i) or Section 2(b)(ii) of
                  this Agreement, then the principal amount of the Debenture
                  shall be increased in an amount equal to Fifty Thousand
                  Dollars ($50,000) for each period of thirty (30) calendar days
                  that the Company has not complied in full with the
                  requirements of Section 2(b)(i) and/or Section 2(b)(ii) (the
                  "Default Penalties"), up to a maximum amount equal to the
                  $350,000 (the "Maximum Penalty"). Any and all Default
                  Penalties incurred pursuant to this Section 2(b)(iii) shall be
                  added to the principal amount of the Debenture and shall be
                  payable and convertible according to the same terms and
                  conditions as the Settlement Amount. In no event shall the
                  aggregate increase in the principal amount of the Debenture
                  due to the Settlement Amount and the Default Penalties exceed
                  One Million Dollars ($1,000,000). The remedy provided in this

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                  Section 2(b)(iii) shall be in lieu of any other remedies
                  otherwise available under the Transaction Agreements with
                  respect to the Company's obligations to make the Securities
                  Filings or other filings under the 1934 Act, to obtain
                  Relisting and to file, obtain and maintain effectiveness of
                  the Registration Statement; provided, however, that the
                  Investor retains its right under Section 15 of the Debenture
                  to declare the Debenture immediately due and payable if an
                  Event of Default occurs under Section 15(k) or Section 15(m)
                  of the Debenture.

         3. OTHER AMENDMENTS TO THE RRA.

                  (a) Section 10 of the RRA is hereby amended and restated to
         read in its entirety as follows:

                           "10. AMENDMENT OR WAIVER OF RIGHTS. Any provision of
                  this Agreement may be amended and the observance thereof may
                  be waived (either generally or in a particular instance and
                  either retroactively or prospectively), only with the written
                  consent of the Company and Investors who beneficially own
                  collectively eighty percent (80%) of the Registrable
                  Securities. Any amendment or waiver effected in accordance
                  with this Section 10 shall be binding upon each Investor and
                  the Company."

                  (b) Section 11(b) of the RRA is hereby amended to reflect that
         the address for notices to the Investors is:

                           c/o Thomson Kernaghan & Co., Limited
                           120 Adelaide Street West, Suite 1600
                           Toronto, Ontario M5H 1T1

         4. MISCELLANEOUS.

                  (a) All other terms and provisions of the RRA not expressly
modified by this First Amendment shall remain in full force and effect;
provided, however, that to the extent any provisions of the RRA or any of the
other Transaction Agreements (as defined in the Securities Purchase Agreement)
are in conflict with the provisions of this First Amendment, the provisions of
this First Amendment shall control.

                  (b) This First Amendment, along with the other Transaction
Agreements and the Debenture Amendment, shall constitute and contain the
complete understanding and agreement of the parties hereto, and cancel and
supersede any and all prior negotiations, correspondence, understandings and
agreements, whether written or oral, between the parties with respect to the
subject matter hereof.

                  (c) The parties acknowledge and agree that this First
Amendment is binding upon Carbon Mesa in accordance with Section 10 of the RRA.

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         IN WITNESS WHEREOF, the parties have executed this First Amendment to
be effective as of the date upon which this First Amendment has been executed by
both signatories to this First Amendment.

Dated: September 24, 2001                       BIOGAN INTERNATIONAL, INC.

                                                By: /S/ G. Laverdiere
                                                    ----------------------------
                                                    Its: President
                                                         -----------------------

Dated: September 24, 2001                       THOMSON KERNAGHAN & CO., LIMITED

                                                By: /S/ Gregg Badger
                                                    ----------------------------
                                                    Its: Sr. VP & Director
                                                         -----------------------<PAGE>

EXHIBIT 4.12

                         ADDENDUM TO FIRST AMENDMENT TO
             8% SECURED CONVERTIBLE DEBENTURE DUE FEBRUARY 28, 2002

         THIS ADDENDUM TO FIRST AMENDMENT TO 8% SECURED CONVERTIBLE DEBENTURE
DUE FEBRUARY 28, 2002 (this "Addendum") is made and effective as of September
24, 2001, by and between BIOGAN INTERNATIONAL, INC., a Delaware corporation (the
"Company"), and THOMSON KERNAGHAN & CO., LIMITED, a Canadian limited liability
company (the "Holder").

                                 R E C I T A L S

         A. Effective as of September 24, 2001, the Company and the Holder
entered into the First Amendment to 8% Secured Convertible Debenture due
February 28, 2002 ("First Amendment").

         B. The Company and the Holder desire to add an additional term to the
First Amendment on the terms and conditions set forth herein.

                                A G R E E M E N T

         NOW, THEREFORE, for and in consideration of the premises and the mutual
covenants set forth herein and in the First Amendment, the parties hereto do
hereby agree as follows:

         1.       Amendment to Section 4E of the Debenture.
                  ----------------------------------------

                  The first sentence of Section 4E of the Debenture is hereby
         amended and restated to read in its entirety as follows:

                  "E. Notwithstanding any other provision hereof, of the
         Warrants, of any of the other Transaction Agreements (as those terms
         are defined in the Securities Purchase Agreement) or of the Company's
         Amended Certificate of Designations of Series A Convertible Preferred
         Stock, in no event (except (i) with respect to an automatic conversion,
         if any, of a Debenture as provided in the Debentures, (ii) as
         specifically provided in this Debenture as an exception to this
         provision, or (iii) while there is outstanding a tender offer for any
         or all of the shares of the Company's Common Stock) shall the Holder be
         entitled to convert all or any portion of this Debenture or to convert
         all or any shares of Series A Convertible Preferred Stock (and the
         Company shall not have the right to pay interest on this Debenture in
         shares of Common Stock) to the extent that, after such conversion, the
         sum of (1) the number of shares of Common Stock beneficially owned by
         the Holder and its affiliates (other than shares of Common Stock that
         may be deemed beneficially owned through the ownership of the
         unconverted portion of the Debentures or unconverted shares of Series A
         Convertible Preferred Stock), and (2) the number of shares of Common
         Stock issuable upon conversion of the Debentures or Series A
         Convertible Preferred Stock or upon exercise of the Warrants with
         respect to which the determination of this proviso is being made, would
         result in beneficial ownership by the Holder and its affiliates of more
         than 9.99% of the outstanding shares of Common Stock (after taking into
         account the shares to be issued to the Holder upon such conversion or
         exercise).

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         2.       Miscellaneous.
                  -------------

                  (a) All other terms and provisions of the Debenture and the
         First Amendment not expressly modified by this Addendum shall remain in
         full force and effect; provided, however, that to the extent any
         provisions of the Debenture, the First Amendment or any of the other
         Transaction Agreements (as defined in the Securities Purchase
         Agreement) are in conflict with the provisions of this Addendum, the
         provisions of this Addendum shall control.

                  (b) This Addendum, along with the Debenture, the other
         Transaction Agreements and the First Amendment to Registration Rights
         Agreement, shall constitute and contain the complete understanding and
         agreement of the parties hereto, and cancel and supersede any and all
         prior negotiations, correspondence, understandings and agreements,
         whether written or oral, between the parties with respect to the
         subject matter hereof.

         IN WITNESS WHEREOF, the parties have executed this Addendum to be
effective as of September 24, 2001.

Dated: October 3, 2001                          BIOGAN INTERNATIONAL, INC.

                                                By: /S/ G. Laverdiere
                                                    ----------------------------
                                                    Its: President
                                                         -----------------------

Dated: October 3, 2001                          THOMSON KERNAGHAN & CO., LIMITED

                                                By: /S/ Gregg Badger
                                                    ----------------------------
                                                    Its: Sr. VP & Director
                                                         -----------------------

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