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                                                                    EXHIBIT 10.5


NEITHER THIS OPTION NOR THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR
UNDER ANY STATE SECURITIES LAW. IN ADDITION, SUCH SECURITIES MAY NOT BE SOLD,
PLEDGED OR OTHERWISE TRANSFERRED UNLESS (i) THERE IS AN EFFECTIVE REGISTRATION
STATEMENT COVERING THE SECURITIES UNDER THE ACT AND APPLICABLE STATE SECURITIES
LAWS, (ii) THE COMPANY FIRST RECEIVES AN OPINION FROM AN ATTORNEY, REASONABLY
ACCEPTABLE TO THE COMPANY, STATING THAT THE PROPOSED TRANSFER IS EXEMPT FROM
REGISTRATION UNDER THE ACT AND UNDER ALL APPLICABLE STATE SECURITIES LAWS, OR
(iii) THE TRANSFER IS MADE PURSUANT TO RULE 144 PROMULGATED UNDER THE ACT.

No _____                                                     For the Purchase of
                                                  _______ shares of Common Stock


                           OPTION FOR THE PURCHASE OF
                             SHARES OF COMMON STOCK
                                       OF
                            MOLICHEM MEDICINES, INC.
                       (formerly Cortez Development, Ltd.)
                            (A Delaware corporation)

         FOR VALUE RECEIVED, MoliChem Medicines, Inc. (formerly Cortez
Development, Ltd.) ("Company"), hereby certifies that ___________ or his, her or
its registered assigns ("Holder"), with its principal offices at
____________________________________________________ is entitled, subject to the
terms set forth below, to purchase from the Company, at any time or from time to
time for the period commencing on _____________ and expiring on _____________,
______________ (_________) shares of Common Stock, $0.0001 par value, of the
Company ("Common Stock"), at an initial purchase price equal to US$_______ per
share. The number of shares of Common Stock purchasable upon exercise of this
Option, and the purchase price per share, each as adjusted from time to time
pursuant to the provisions of this Option, are hereinafter referred to as the
"Option Shares" and the "Exercise Price," respectively.

1.       Exercise

         1.1 Procedure for Exercise. This Option may be exercised by the Holder,
in whole or in part, by the surrender of this Option (with the Notice of
Exercise Form attached hereto duly executed by such Holder) at the principal
office of the Company, or at such other office or agency as the Company may
designate, accompanied by payment in full, in lawful money of the United States,
of an amount equal to the then applicable Exercise Price multiplied by the
number of Option Shares then being purchased upon such exercise.



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         1.2 Date of Exercise. Each exercise of this Option shall be deemed to
have been effected immediately prior to the close of business on the day on
which this Option shall have been surrendered to the Company. At such time, the
person or persons in whose name or names any certificates for Option Shares
shall be issuable upon such exercise shall be deemed to have become the holder
or holders of record of the Option Shares represented by such certificates.

         1.3 Issuance of Certificate. As soon as practicable after the exercise
of the purchase right represented by this Option, the Company at its expense
will use its best efforts to cause to be issued in the name of, and delivered
to, the Holder, or, subject to the terms and conditions hereof, to such other
individual or entity as such Holder (upon payment by such Holder of any
applicable transfer taxes) may direct:

         (i) a certificate or certificates for the number of full shares of
Option Shares to which such Holder shall be entitled upon such exercise plus, in
lieu of any fractional share to which such Holder would otherwise be entitled,
cash in an amount determined pursuant to Section 4 hereof, and

         (ii) in case such exercise is in part only, a new option or options
(dated the date hereof) of like tenor, stating on the face or faces thereof the
number of shares currently stated on the face of this Option minus the number of
such shares purchased by the Holder upon such exercise as provided in subsection
1.1 above.

2.       Adjustments.

         2.1 Split, Subdivision or Combination of Shares. If the outstanding
shares of the Company's Common Stock at any time while this Option remains
outstanding and unexpired shall be subdivided or split into a greater number of
shares, or a dividend in Common Stock shall be paid in respect of Common Stock,
the Exercise Price in effect immediately prior to such subdivision or at the
record date of such dividend shall, simultaneously with the effectiveness of
such subdivision or split or immediately after the record date of such dividend
(as the case may be), shall be proportionately decreased. If the outstanding
shares of Common Stock shall be combined or reverse-split into a smaller number
of shares, the Exercise Price in effect immediately prior to such combination or
reverse split shall, simultaneously with the effectiveness of such combination
or reverse split, be proportionately increased. When any adjustment is required
to be made in the Exercise Price, the number of shares of Option Shares
purchasable upon the exercise of this Option shall be changed to the number
determined by dividing (i) an amount equal to the number of shares issuable upon
the exercise of this Option immediately prior to such adjustment, multiplied by
the Exercise Price in effect immediately prior to such adjustment, by (ii) the
Exercise Price in effect immediately after such adjustment.

         2.2 Reclassification Reorganization, Consolidation or Merger. In the
case of any reclassification of the Common Stock (other than a change in par
value or a subdivision or combination as provided for in subsection 2.1 above),
or any reorganization, consolidation or merger of the Company with or into
another corporation (other than a merger or reorganization with respect to which
the Company is the continuing corporation and which does not result in any
reclassification of the Common Stock), or a transfer of all or substantially all
of the assets of the Company, or the

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payment of a liquidating distribution then, as part of any such reorganization,
reclassification, consolidation, merger, sale or liquidating distribution,
lawful provision shall be made so that the Holder of this Option shall have the
right thereafter to receive upon the exercise hereof, the kind and amount of
shares of stock or other securities or property which such Holder would have
been entitled to receive if, immediately prior to any such reorganization,
reclassification, consolidation, merger, sale or liquidating distribution, as
the case may be, such Holder had held the number of shares of Common Stock which
were then purchasable upon the exercise of this Option. In any such case,
appropriate adjustment (as reasonably determined by the Board of Directors of
the Company) shall be made in the application of the provisions set forth herein
with respect to the rights and interests thereafter of the Holder of this Option
such that the provisions set forth in this Section 2 (including provisions with
respect to the Exercise Price) shall thereafter be applicable, as nearly as is
reasonably practicable, in relation to any shares of stock or other securities
or property thereafter deliverable upon the exercise of this Option.

         2.3 Price Adjustment. No adjustment in the per share Exercise Price
shall be required unless such adjustment would require an increase or decrease
in the Exercise Price of at least $0.01; provided, however, that any adjustments
which by reason of this paragraph are not required to be made shall be carried
forward and taken into account in any subsequent adjustment. All calculations
under this Section 2 shall be made to the nearest cent or to the nearest 1/100th
of a share, as the case may be.

         2.4 No Impairment. The Company will not, by amendment of its Articles
of Incorporation or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed hereunder by the Company but will at all
times in good faith assist in the carrying out of all the provisions of this
Section 2 and in the taking of all such actions as may be necessary or
appropriate in order to protect against impairment of the rights of the Holder
of this Option to adjustments in the Exercise Price.

         2.5 Notice of Adjustment. Upon any adjustment of the Exercise Price or
extension of the Option exercise period, the Company shall forthwith give
written notice thereto to the Holder of this Option describing the event
requiring the adjustment, stating the adjusted Exercise Price and the adjusted
number of shares purchasable upon the exercise hereof resulting from such event,
and setting forth in reasonable detail the method of calculation and the facts
upon which such calculation is based.

3. Fractional Shares. The Company shall not be required to issue fractions of
shares of Common Stock upon exercise. If any fractions of a share would, but for
this Section 3, be issuable upon any exercise, in lieu of such fractional share
the Company shall round up or down to the nearest whole number.

4. Limitation on Sales. Each holder of this Option acknowledges that this Option
and the Option Shares, as of the date of original issuance of this Option, have
not been registered under the Securities Act of 1933, as amended ("Act"), and
agrees not to sell, pledge, distribute, offer for sale, transfer or otherwise
dispose of this Option or any Option Shares issued upon its exercise in the


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absence of (a) an effective registration statement under the Act as to this
Option or such Option Shares or (b) an opinion of counsel, reasonably acceptable
to the Company, that such registration and qualification are not required. The
Option Shares issued upon exercise thereof shall be imprinted with a legend in
substantially the following form:

THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, OR UNDER ANY STATE SECURITIES LAWS, AND MAY
NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED UNLESS (i) THERE IS AN EFFECTIVE
REGISTRATION STATEMENT COVERING THE SHARES UNDER THE ACT AND APPLICABLE STATE
SECURITIES LAWS, (ii) THE COMPANY FIRST RECEIVES AN OPINION FROM AN ATTORNEY,
REASONABLY ACCEPTABLE TO THE COMPANY, STATING THAT THE PROPOSED TRANSFER IS
EXEMPT FROM REGISTRATION UNDER THE ACT AND UNDER ALL APPLICABLE STATE SECURITIES
LAWS, OR (iii) THE TRANSFER IS MADE PURSUANT TO RULE 144 PROMULGATED UNDER THE
ACT.

5. Notices of Record Date. In case: (i) the Company shall take a record of the
holders of its Common Stock (or other stock or securities at the time
deliverable upon the exercise of this Option) for the purpose of entitling or
enabling them to receive any dividend or other distribution, or to receive any
right to subscribe for or purchase any shares of any class or any other
securities, or to receive any other right, or (ii) of any capital reorganization
of the Company, any reclassification of the capital stock of the Company, any
consolidation or merger of the Company with or into another corporation (other
than a consolidation or merger in which the Company is the surviving entity), or
any transfer of all or substantially all of the assets of the Company, or (iii)
of the voluntary or involuntary dissolution, liquidation or winding-up of the
Company, then, and in each such case, the Company will mail or cause to be
mailed to the Holder of this Option a notice specifying, as the case may be, (i)
the date on which a record is to be taken for the purpose of such dividend,
distribution or right, and stating the amount and character of such dividend,
distribution or right, or (ii) the effective date on which such reorganization,
reclassification, consolidation, merger, transfer, dissolution, liquidation or
winding-up is to take place, and the time, if any is to be fixed, as of which
the holders of record of Common Stock (or such other stock or securities at the
time deliverable upon the exercise of this Option) shall be entitled to exchange
their shares of Common Stock (or such other stock or securities) for securities
or other property deliverable upon such reorganization, reclassification,
consolidation, merger, transfer, dissolution, liquidation or winding-up. Such
notice shall be mailed at least ten (10) days prior to the record date or
effective date for the event specified in such notice, provided that the failure
to mail such notice shall not affect the legality or validity of any such
action.

6. Reservation of Stock. The Company will at all times reserve and keep
available, solely for issuance and delivery upon the exercise of this Option,
such shares of Common Stock and other stock, securities and property, as from
time to time shall be issuable upon the exercise of this Option.

7. Replacement of Options. Upon receipt of evidence reasonably satisfactory to
the Company of the loss, theft, destruction or mutilation of this Option and (in
the case of loss, theft or destruction) upon delivery of an indemnity agreement
(with surety if reasonably required) in an amount


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reasonably satisfactory to the Company, or (in the case of mutilation) upon
surrender and cancellation of this Option, the Company will issue, in lieu
thereof, a new Option of like tenor.

8.       Transfers, etc.

         8.1 Option Register. The Company will maintain a register containing
the names and addresses of the Holders of this Option. Any Holder may change
its, his or her address as shown on the option register by written notice to the
Company requesting such change.

         8.2 Holder. Until any transfer of this Option is made in the option
register, the Company may treat the Holder of this Option as the absolute owner
hereof for all purposes; provided, however, that if and when this Option is
properly assigned in blank, the Company may (but shall not be obligated to)
treat the bearer hereof as the absolute owner hereof for all purposes,
notwithstanding any notice to the contrary.

9. No Rights as Stockholder. Until the exercise of this Option, the Holder of
this Option shall not have or exercise any rights by virtue hereof as a
stockholder of the Company.

10. Successors. The rights and obligations of the parties to this Option will
inure to the benefit of and be binding upon the parties hereto and their
respective heirs, successors, assigns, pledgees, transferees and purchasers.
Without limiting the foregoing, the registration rights set forth in this Option
shall inure to the benefit of the Holder and all the Holder's successors, heirs,
pledgees, assignees, transferees and purchasers of this Option and the Option
Shares.

11. Change or Waiver. Any term of this Option may be changed or waived only by
an instrument in writing signed by the party against which enforcement of the
change or waiver is sought.

12. Headings. The headings in this Option are for purposes of reference only and
shall not limit or otherwise affect the meaning of any provision of this Option.

13. Governing Law. This Option shall be governed by and construed in accordance
with the laws of the State of New York as such laws are applied to contracts
made and to be fully performed entirely within that state between residents of
that state.

14. Jurisdiction and Venue. The Company (i) agrees that any legal suit, action
or proceeding arising out of or relating to this Option shall be instituted
exclusively in New York State Supreme Court, County of New York or in the United
States District Court for the Southern District of New York, (ii) waives any
objection to the venue of any such suit, action or proceeding and the right to
assert that such forum is not a convenient forum for such suit, action or
proceeding, and (iii) irrevocably consents to the jurisdiction of the New York
State Supreme Court, County of New York, and the United States District Court
for the Southern District of New York in any such suit, action or proceeding,
and the Company further agrees to accept and acknowledge service or any and all
process which may be served in any such suit, action or proceeding in New York
State Supreme Court, County of New York or in the United States District Court
for the Southern District of New

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York and agrees that service of process upon it mailed by certified mail to its
address shall be deemed in every respect effective service of process upon it in
any suit, action or proceeding.

15. Mailing of Notices, etc. All notices and other communications under this
Option (except payment) shall be in writing and shall be sufficiently given if
sent to the Holder or the Company, as the case may be, by hand delivery, private
overnight courier, with acknowledgment of receipt, or by registered or certified
mail, return receipt requested, as follows:

         Holder:            To Holder's address on page 1 of this Option
                            Attention: Name of Holder

         The Company:       To the Company's Principal Executive Offices
                            Attention: President

or to such other address as any of them, by notice to the others may designate
from time to time. Time shall be counted to, or from, as the case may be, the
delivery in person or by overnight courier or five (5) business days after
mailing.


                                 MOLICHEM MEDICINES, INC.



                                 By:
                                    ------------------------------------------
                                 Name:
                                 Title:


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                               NOTICE OF EXERCISE


TO:      MoliChem Medicines, Inc.

         1. The undersigned hereby elects to purchase ________ shares of the
Common Stock of MoliChem Medicines, Inc., pursuant to terms of the attached
Option, and tenders herewith payment of the Exercise Price of such shares in
full, together with all applicable transfer taxes, if any.

         2. Please issue a certificate or certificates representing said shares
of the Common Stock in the name of the undersigned or in such other name as is
specified below:

         3. The undersigned represents that it will sell the shares of Common
Stock pursuant to an effective Registration Statement under the Securities Act
of 1933, as amended, or an exemption from registration thereunder.


                                     ------------------------------------------
                                     (Name)


                                     ------------------------------------------
                                     (Address)


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


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


                                     ------------------------------------------
                                     (Taxpayer Identification Number)



--------------------------------------------------------------
(Print Name of Holder)


By:
   -----------------------------------------------------------

Title:
      --------------------------------------------------------

Date:
     ---------------------------------------------------------


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