<PAGE>   1
                                                                     EXHIBIT 4.2


THIS WARRANT AND THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY OTHER SECURITIES LAWS, HAVE BEEN
TAKEN FOR INVESTMENT, AND MAY NOT BE SOLD OR TRANSFERRED OR OFFERED FOR SALE OR
TRANSFER UNLESS A REGISTRATION STATEMENT UNDER SUCH ACT AND OTHER APPLICABLE
SECURITIES LAWS WITH RESPECT TO SUCH SECURITIES IS THEN IN EFFECT, OR IN THE
OPINION OF COUNSEL (WHICH OPINION IS REASONABLY SATISFACTORY TO THE ISSUER OF
THESE SECURITIES), SUCH REGISTRATION UNDER SUCH ACT AND OTHER APPLICABLE
SECURITIES LAWS IS NOT REQUIRED.

         Warrant Certificate                             Warrant to Purchase
          ***_________***                                  ***________***
               Number                                          Shares


                          INTERNATIONAL ISOTOPES, INC.

               (Incorporated under the laws of the State of Texas)

                WARRANT CERTIFICATE FOR THE PURCHASE OF SHARES OF

         THE $.01 PAR VALUE COMMON STOCK OF INTERNATIONAL ISOTOPES, INC.



     Warrant Price: $5.50 per share subject to adjustment as provided below.

         THIS IS TO CERTIFY that, for value received, ***________________*** or
its registered assigns (either or both of whom are referred to herein as the
"Holder"), is entitled to purchase, subject to the terms and conditions
hereinafter set forth, up to ***______*** shares of the $.01 par value common
stock ("Common Stock") of International Isotopes, Inc., a Texas corporation (the
"Company"), and to receive certificate(s) for the Common Stock so purchased.


         1. Exercise Period and Vesting. This Warrant is issued by the Company
pursuant to that certain Subscription Agreement between the Company and Holder
(the "Agreement"). The "Exercise Period" is the period beginning on the date of
this Warrant (the "Issuance Date") and ending at 5:00 p.m., Dallas, Texas time,
on January ___, 2003. This Warrant will terminate automatically and immediately
upon the expiration of the Exercise Period.

         2. Exercise of Warrant. This Warrant may be exercised, in whole or in
part, at any time and from time to time during the Exercise Period. Such
exercise shall be accomplished by tender to the Company of the purchase price
set forth above as the warrant price (the "Warrant Price"), in cash or by
certified check or bank cashier's check, payable to the order of the Company,
together with presentation and surrender to the Company of this Warrant
Certificate with an executed subscription in substantially the form attached
hereto as Exhibit A. Upon receipt of the foregoing, the Company will deliver to
the Holder, as promptly as possible, a certificate or certificates representing
the shares of Common Stock so purchased, registered in the name of the Holder or
its designee. With respect to any exercise of this Warrant, the Holder will for
all purposes be deemed to have become the holder of record of the number of
shares of Common Stock purchased hereunder on the date this Warrant and payment
of the Warrant Price is received by the Company (the "Exercise Date"),
irrespective of the date of delivery of the certificate evidencing such shares,
except that, if the date of such receipt is a date on which the stock transfer
books of the Company are closed, such person will be deemed to have become the
holder of such shares at the close of business on the next succeeding date on
which the stock transfer books are open. Fractional shares of Common Stock will
not be issued upon the exercise of this Warrant. In lieu of any fractional
shares that would have been issued but for the immediately preceding sentence,
the Holder will be entitled to receive cash equal to the current market price of
such fraction of a share of Common Stock on the trading day immediately
preceding the Exercise Date. In the event this Warrant is exercised in part, the
Company shall



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<PAGE>   2


issue a new Warrant Certificate to the Holder covering the aggregate number of
shares of Common Stock as to which this Warrant remains exercisable.

         3. Transferability and Exchange. (a) This Warrant and the Common Stock
issuable upon the exercise hereof may not be sold, transferred, pledged or
hypothecated, without the prior written consent of the Company, and in the event
of any such transfer, pledge or hypothecation,the Company shall have been
provided with an opinion of counsel (which may or may not be counsel for the
Company), or other evidence reasonably satisfactory to it, that such transfer is
not in violation of the Securities Act, and any applicable state securities
laws. Subject to the satisfaction of the aforesaid conditions, this Warrant and
such shares of Common Stock shall be transferable from time to time by the
Holder upon written notice to the Company. If this Warrant is transferred, in
whole or in part, upon surrender of this Warrant to the Company, the Company
shall deliver to each transferee a Warrant evidencing the rights of such
transferee to purchase the number of shares of Common Stock that such transferee
is entitled to purchase pursuant to such transfer. The Company may place a
legend on this Warrant or any replacement Warrant and on each certificate
representing shares issuable upon exercise of this Warrant as to which the
Company has not been provided evidence that the transfer of such security would
not be in violation of the Securities Act and any applicable state securities
laws. Only a registered Holder may enforce the provisions of this Warrant
against the Company. A transferee of the original registered Holder becomes a
registered Holder only upon delivery to the Company of the original Warrant and
an original Assignment, substantially in the form set forth in Exhibit B
attached hereto.

         (b) This Warrant is exchangeable upon its surrender by the Holder to
the Company for new Warrants of like tenor and date representing in the
aggregate the right to purchase the number of shares purchasable hereunder, each
of such new Warrants to represent the right to purchase such number of shares as
may be designated by the Holder at the time of such surrender.

         (c) The holder of this Warrant understands that this Warrant has not
been and is not expected to be, registered under the Securities Act or any state
securities laws, and, assuming the consent of the Company is obtained pursuant
to Section 3(1) hereof, may not be offered for sale, sold, assigned or
transferred unless (a) subsequently registered thereunder, or (b) such holder
shall have delivered to the Company an opinion of counsel, from counsel and in
form reasonably acceptable to the Company, to the effect that the securities to
be sold, assigned or transferred may be sold, assigned or transferred pursuant
to an exemption from such registration all shares purchasable upon excise of the
Warrant and to all resales or other transfers thereof pursuant to the Securities
Act.

         4. Adjustments to Warrant Price. The Warrant Price and, to the extent
specifically provided, the number of shares of Common Stock purchasable upon the
exercise of this Warrant are subject to adjustment from time to time upon the
occurrence of any of the events specified in this Section 4. For the purpose of
this Section 4, the following terms shall have the following meanings:

                  (i) "Common Stock" shall mean the Company's common stock, par
value $0.01 per share, and any capital stock into which such Common Stock shall
have been changed or any capital stock resulting from a reclassification of such
Common Stock.

                  (ii) "Approved Stock Plan" shall mean any plan which has been
approved by the Board of Directors of the Company, pursuant to which the
Company's securities may be issued to any employee, officer, director,
consultant or other service provider for services provided to the Company.

                  (iii) "Other Securities" means (i) those rights, warrants,
options or convertible securities of the Company issued prior to, and
outstanding on, the date of issuance of this Warrant, or Common Stock issued or
issuable upon the exercise or conversion of such rights, warrants, options or
convertible securities, (ii) the Common Stock issued pursuant to this Agreement
or the Warrant or other warrants issued pursuant to the Agreement or shares
issuable upon exercise of the Warrant or such other warrants and any shares
issued or issuable (or deemed issued or issuable) by virtue of the operation of
the antidilution provisions or Reset Price of the Warrant or other warrants
issued pursuant to the Agreement, or (iii) securities issued or issuable
pursuant to transactions arranged by or pursuant to which Stonegate Securities
or its affiliates acted as placement agent, finder, intermediary, underwriter.

         (a) In the event that on the 180th day following the Issuance Date (the
"Reset Date") the average closing bid price for the Common Stock during the
twenty consecutive trading day period



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<PAGE>   3


immediately prior to the Reset Date (the "Reset Price") is less than the Warrant
Price, then the Warrant Price shall then be adjusted to equal the Reset Price.

         (b) In case the Company shall (i) pay a dividend or make a distribution
in shares of Common Stock or other securities, (ii) subdivide its outstanding
shares of Common Stock into a greater number of shares, (iii) combine its
outstanding shares of Common Stock into a smaller number of shares, or (iv)
issue by reclassification of its shares of Common Stock other securities of the
Company, then the Warrant Price in effect at the time of the record date for
such dividend or of the effective date of such subdivision, combination or
reclassification, or the number and kind of securities issuable on such date,
shall be proportionately adjusted so that the Holder of any Warrant thereafter
exercised shall be entitled to receive the aggregate number and kind of shares
of Common Stock (or such other securities other than Common Stock) of the
Company that, if such Warrant had been exercised immediately prior to such date,
the Holder would have owned upon such exercise and been entitled to receive by
virtue of such dividend, subdivision, combination or reclassification. Such
adjustment shall be made successively whenever any event listed above shall
occur.

         (c) In case the Company shall issue or sell any shares of Common Stock
to all of its existing stockholders for a consideration per share less than the
current market price per share of Common Stock on the date of such issue or
sale, except for securities issued or issuable (or deemed issued or issuable) in
connection with an Approved Stock Plan or for Other Securities, then in each
such case the Warrant Price shall forthwith be adjusted to equal the then
current Warrant Price times the quotient obtained by dividing (i) the sum of (x)
the number of shares of Common Stock outstanding immediately prior to such issue
or sale, plus (y) the consideration, if any, received by the Company upon such
issue or sale, divided by the current market price per share of Common Stock on
the date of such issue or sale, by (ii) the number of shares of Common Stock
outstanding immediately after such issue or sale.

         In any determination of an adjusted Warrant Price, (i) the number of
shares of Common Stock outstanding at any given time shall exclude shares in the
treasury of the Company and shall include shares issuable in respect of script
certificates issued in lieu of fractions of shares of Common Stock, (ii) in the
case of the issue of shares of Common Stock for cash, the consideration received
by the Company therefor shall be deemed to be the amount of cash received by the
Company for such shares, without deduction of the costs, expenses, fees and
commissions incidental to the issue and sale thereof, and (iii) in the case of
the issue of shares of Common Stock for a consideration in whole or in part
other than cash, the consideration received by the Company therefor shall be
deemed to be the fair value to the Company of such consideration as determined
in good faith by, and reflected in a formal resolution of, the Board of
Directors of the Company.

         In case of the issuance by the Company of any security that is
convertible into shares of Common Stock at a price less than the current market
price per share of Common Stock on the date of such issuance, or of any rights,
warrants or options to purchase shares of Common Stock at a price less than the
current market price per share of Common Stock on the date of such issuance, (i)
the Company shall be deemed to have issued the maximum number of shares of
Common Stock deliverable upon the exercise of such conversion privileges or
rights, warrants or options, and (ii) the consideration therefor shall be deemed
to be (A) the consideration actually received by the Company for the issuance of
such convertible securities, rights, warrants or options, as the case may be,
without deduction of the costs, expenses, fees and commissions incidental to the
issue and sale thereof, plus (B) the additional minimum consideration, if any,
to be received by the Company in connection with such conversion or upon the
exercise of such rights, warrants or options. No further adjustment of the
Warrant Price shall be made as a result of the actual issuance of the shares of
Common Stock referred to in this paragraph. Upon the expiration of such rights,
warrants or options, or the termination of such privilege to convert, the
Warrant Price and the number of shares of Common Stock purchasable upon exercise
of this Warrant shall be readjusted to such Warrant Price and such number of
shares of Common Stock as would have pertained had the adjustments made upon the
issuance of such rights, warrants, options or convertible securities been made
upon the basis of the issuance of only the number of shares of Common Stock
actually delivered upon the exercise of such rights, warrants or options or upon
the conversion of such securities.

         (d) In case the Company shall fix a record date for the making of a
distribution to all holders of Common Stock (including any such distribution
made in connection with a consolidation or merger in



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<PAGE>   4


which the Company is the surviving corporation) of cash, evidences of
indebtedness or assets, or subscription rights or warrants (excluding those
referred to in subsection (b) above), the Warrant Price to be in effect after
such record date shall be determined by multiplying the Warrant Price in effect
immediately prior to such record date by a fraction, the numerator of which
shall be the current market price per share of Common Stock on such record date,
less the amount of cash so to be distributed (or the fair market value (as
determined in good faith by, and reflected in a formal resolution of, the Board
of Directors of the Company) of the portion of the assets or evidences of
indebtedness so to be distributed, or of such subscription rights or warrants,
applicable to one share of Common Stock, and the denominator of which shall be
such current market price per share of Common Stock. Such adjustment shall be
made successively whenever such a record date is fixed; and in the event that
such distribution is not so made, the Warrant Price shall again be adjusted to
be the Warrant Price which would then be in effect if such record date had not
been fixed.

         (e) For the purpose of any computation under any subsection of this
Section 4, the "current market price" per share of Common Stock on any date
shall be the per share price of the Common Stock on the trading day immediately
prior to the event requiring an adjustment hereunder and shall be: (i) if the
principal trading market for such securities is a national or regional
securities exchange, the closing price on such exchange on such day; or (ii) if
sales prices for shares of Common Stock are reported by the Nasdaq National
Market System or Nasdaq Small Cap Market (or a similar system then in use), the
last reported sales price so reported on such day; or (iii) if neither (i) nor
(ii) above are applicable, and if bid and ask prices for shares of Common Stock
are reported in the over-the-counter market by Nasdaq (or, if not so reported,
by the National Quotation Bureau), the average of the high bid and low ask
prices so reported on such day. Notwithstanding the foregoing, if there is no
reported closing price, last reported sales price, or bid and ask prices, as the
case may be, for the day in question, then the current market price shall be
determined as of the latest date prior to such day for which such closing price,
last reported sales price, or bid and ask prices, as the case may be, are
available, unless such securities have not been traded on an exchange or in the
over-the-counter market for 30 or more days immediately prior to the day in
question, in which case the current market price shall be determined in good
faith by, and reflected in a formal resolution of, the Board of Directors of the
Company.

         (f) Notwithstanding any provision herein to the contrary, no adjustment
in the Warrant Price shall be required unless such adjustment would require an
increase or decrease of at least 1% in the Warrant Price; provided, however,
that any adjustments which by reason of this subsection (e) are not required to
be made shall be carried forward and taken into account in any subsequent
adjustment. All calculations under this Section 4 shall be made to the nearest
cent or the nearest one-hundredth of a share, as the case may be.

         (g) In the event that at any time, as a result of an adjustment made
pursuant to Section 4(b), the Holder of any Warrant thereafter exercised shall
become entitled to receive any shares of capital stock of the Company other than
shares of Common Stock, thereafter the number of such other shares so receivable
upon exercise of any Warrant shall be subject to adjustment from time to time in
a manner and on terms as nearly equivalent as practicable to the provisions with
respect to the shares of Common Stock contained in this Section 4, and the other
provisions of this Warrant shall apply on like terms to any such other shares.

         (h) If the Company merges or consolidates into or with another
corporation or entity, or if another corporation or entity merges into or with
the Company (excluding such a merger in which the Company is the surviving or
continuing corporation and which does not result in any reclassification,
conversion, exchange, or cancellation of the outstanding shares of Common
Stock), or if all or substantially all of the assets or business of the Company
are sold or transferred to another corporation, entity, or person, then, as a
condition to such consolidation, merger, or sale (a "Transaction"), lawful and
adequate provision shall be made whereby the Holder shall have the right from
and after the Transaction to receive, upon exercise of this Warrant and upon the
terms and conditions specified herein and in lieu of the shares of the Common
Stock that would have been issuable if this Warrant had been exercised
immediately before the Transaction, such shares of stock, securities, or assets
as the Holder would have owned immediately after the Transaction if the Holder
had exercised this Warrant immediately before the effective date of the
Transaction. The Company shall not effect any Transaction unless prior to or
simultaneously with the consummation thereof the successor corporation, entity,
or person (if other than the Company) resulting



                                       4
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from the Transaction or purchasing assets or the business of the Company in the
Transaction shall assume by written instrument the obligation to deliver to the
Holder such shares of stock, securities, or assets as, in accordance with the
foregoing provisions, the Holder may be entitled to receive.

         (i) In case any event shall occur as to which the other provisions of
this Section 4 are not strictly applicable but the failure to make any
adjustment would not fairly protect the purchase rights represented by this
Warrant in accordance with the essential intent and principles hereof, then, in
each such case, the Company shall effect such adjustment, on a basis consistent
with the essential intent and principles established in this Section 4, as may
be necessary to preserve, without dilution, the purchase rights represented by
this Warrant.

         5. Representations of Holder. The holder of this Warrant, by the
acceptance hereof, represents that it is acquiring this Warrant and the shares
issuable upon exercise of this Warrant for its own account for investment only
and not with a view towards, or for resale in connection with, the public sale
or distribution of this Warrant or the shares issuable upon exercise of this
Warrant, except pursuant to sales registered or exempted under the Securities
Act. The holder of this Warrant further represents, by acceptance hereof, that,
as of this date, such holder is an "accredited investor" as such term is defined
in Rule 501(a)(1) of Regulation D promulgated by the Securities and Exchange
Commission under the Securities Act (an "Accredited Investor"). Upon exercise of
this Warrant, the holder shall confirm in writing, in a form satisfactory to the
Company, that the shares issuable upon exercise of the Warrant are being
acquired solely for the holder's own account and not as a nominee for any other
party, for investment, and not with a view toward distribution or resale and
that such holder is an Accredited Investor. If such holder cannot make such
representations because they would be factually incorrect, it shall be a
condition to such holder's exercise of this Warrant that the Company receive
such other representations as the Company considers reasonably necessary to
assure the Company that the issuance of its securities upon exercise of this
Warrant shall not violate any United States or state securities laws.

         6. Registration Rights. The Holder shall be entitled to the benefits of
the registration rights set forth in that certain Registration Rights Agreement
by and among the Company and the Holders of the Warrants dated January ___,
2000.

         7. Reservation of Shares. The Company agrees at all times to reserve
and hold available out of the aggregate of its authorized but unissued Common
Stock the number of shares of its Common Stock issuable upon the full exercise
of this Warrant. The Company further covenants and agrees that all shares of
Common Stock that may be delivered upon the exercise of this Warrant will, upon
delivery, be fully paid and nonassessable and free from all taxes, liens and
charges with respect to the purchase thereof hereunder.

         8. Notices to Holder. Upon any adjustment of the Warrant Price (or
number of shares of Common Stock purchasable upon the exercise of this Warrant)
pursuant to Section 4, the Company shall promptly thereafter cause to be given
to the Holder written notice of such adjustment. Such notice shall include the
Warrant Price (and/or the number of shares of Common Stock purchasable upon the
exercise of this Warrant) after such adjustment, and shall set forth in
reasonable detail the Company's method of calculation and the facts upon which
such calculations were based. Where appropriate, such notice shall be given in
advance and included as a part of any notice required to be given under the
other provisions of this Section 8.

         In the event of (a) any fixing by the Company of a record date with
respect to the holders of any class of securities of the Company for the purpose
of determining which of such holders are entitled to dividends or other
distributions, or any rights to subscribe for, purchase or otherwise acquire any
shares of capital stock of any class or any other securities or property, or to
receive any other right, or (b) any capital reorganization of the Company, or
reclassification or recapitalization of the capital stock of the Company or any
transfer of all or substantially all of the assets or business of the Company
to, or consolidation or merger of the Company with or into, any other entity or
person, or (c) any voluntary or involuntary dissolution or winding up of the
Company, then and in each such event the Company will give the Holder a written
notice specifying, as the case may be, (i) the record date for the purpose of
such dividend, distribution, or right, and stating the amount and character of
such dividend, distribution, or right; or (ii) the date on which any such
reorganization, reclassification, recapitalization, transfer, consolidation,
merger, conveyance, 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 capital stock or securities receivable upon the



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exercise of this Warrant) shall be entitled to exchange their shares of Common
Stock (or such other stock securities) for securities or other property
deliverable upon such event. Any such notice shall be given at least 20 days
prior to the earliest date therein specified.

         9. No Rights as a Stockholder. This Warrant does not entitle the Holder
to any voting rights or other rights as a stockholder of the Company, nor to any
other rights whatsoever except the rights herein set forth.

         10. Additional Covenants of the Company. At such time as the Common
Stock is listed for trading on any regional or national securities exchange or
Nasdaq, the Company shall, upon issuance of any shares for which this Warrant is
exercisable, at its expense, promptly obtain and maintain the listing of such
shares.

         The Company shall comply with the reporting requirements of Sections 13
and 15(d) of the Exchange Act for so long as and to the extent that such
requirements apply to the Company.

         The Company shall not, by amendment of its Certificate 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 of this
Warrant. Without limiting the generality of the foregoing, the Company (a) will
at all times reserve and keep available, solely for issuance and delivery upon
exercise of this Warrant, shares of Common Stock issuable from time to time upon
exercise of this Warrant, (b) will not increase the par value of any shares of
capital stock receivable upon exercise of this Warrant above the amount payable
therefor upon such exercise, and (c) will take all such actions as may be
necessary or appropriate in order that the Company may validly and legally issue
fully paid and nonassessable stock.

         11. Specific Performance. The Company stipulates that remedies at law,
in money damages, available to the Holder or to a holder of Common Stock issued
pursuant to the exercise of this Warrant, in the event of any default or
threatened default by the Company in the performance of or compliance with any
of the terms of this Warrant, are not and will not be adequate. Therefore, the
Company agrees that the terms of this Warrant may be specifically enforced by a
decree for the specific performance of any agreement contained herein or by an
injunction against a violation of any of the terms hereof or otherwise.

         12. Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the Company, the Holder and their respective successors
and permitted assigns.

         13. Notices. The Company agrees to maintain a ledger of the ownership
of the Warrants (the "Warrant Ledger). Any notice hereunder shall be given by
registered or certified mail if to the Company, at its principal executive
office and, if to the Holder, to its address shown in the Warrant Ledger of the
Company, provided that the Holder may at any time on three (3) days' written
notice to the Company designate or substitute another address where notice is to
be given. Notice shall be deemed given and received after a certified or
registered letter, properly addressed with postage prepaid, is deposited in the
U.S. mail.

         14. Severability. Every provision of this Warrant is intended to be
severable. If any term or provision hereof is illegal or invalid for any reason
whatsoever, such illegality or invalidity shall not affect the remainder of this
Warrant.

         15. Governing Law. This Warrant shall be governed by and construed in
accordance with the laws of the State of Texas without giving effect to the
principles of choice of laws thereof. Venue for any dispute arising hereunder
shall lie in the state or federal courts of Dallas County, Texas.

         16. Attorneys' Fees. In any action or proceeding brought to enforce any
provision of this Warrant, the Holder, if successful, shall be entitled to
recover reasonable attorneys' fees in addition to its costs and expenses and any
other available remedy.

         17. Entire Agreement. This Warrant (including the exhibits attached
hereto) constitutes the entire understanding between the Company and the Holder
with respect to the subject matter hereof, and supersedes all prior
negotiations, discussions, agreements and understandings relating to such
subject matter.



                                       6
<PAGE>   7


         IN WITNESS WHEREOF, the Company has caused this Warrant to be executed
by its duly authorized officer, and its corporate seal hereunto affixed.

         DATED:
                --------------------
                                                  INTERNATIONAL ISOTOPES, INC.

                                                  By:
                                                     ---------------------------
                                                  Its:
                                                      --------------------------




                                       7
<PAGE>   8
                                   EXHIBIT A

                                SUBSCRIPTION FORM

         (To be Executed by the Holder to Exercise the Rights To Purchase Common
Stock Evidenced by the Within Warrant)

         The undersigned hereby irrevocably subscribes for ___________ shares
(the "Stock") of the Common Stock of International Isotopes, Inc., ("Company")
pursuant to and in accordance with the terms and conditions of the attached
Warrant, and hereby makes payment of $______________ therefor by tendering cash
or delivering a certified check or bank cashier's check, payable to the order of
the Company. The undersigned requests that a certificate for such shares be
issued in the name of the undersigned and be delivered to the undersigned at the
address stated below. If such number of shares is not all of the shares
purchasable pursuant to the attached Warrant, the undersigned requests that a
new Warrant of like tenor for the balance of the remaining shares purchasable
thereunder be delivered to the undersigned at the address stated below.

         In connection with the issuance of the Stock, I hereby represent to the
Company that I am acquiring the Stock for my own account for investment and not
with a view to, or for resale in connection with, a distribution of the shares
within the meaning of the Securities Act of 1933, as amended (the "Securities
Act").

         I understand that because the Stock has not been registered under the
Securities Act, I must hold such Stock indefinitely unless such Stock is
subsequently registered and qualified under the Securities Act or is exempt from
such registration and qualification. I shall make no transfer or disposition of
the Stock unless (a) such transfer or disposition can be made without
registration under the Securities Act by reason of a specific exemption from
such registration and such qualification, or (b) a registration statement has
been filed pursuant to the Securities Act and has been declared effective with
respect to such disposition.

         I agree that each certificate representing the Stock delivered to me
shall bear substantially the following legend:

                THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE
                SECURITIES ACT OF 1933 (THE "SECURITIES ACT") OR
                UNDER APPLICABLE STATE SECURITIES LAWS AND MAY NOT
                BE SOLD, TRANSFERRED OR OTHERWISE DISPOSED OF
                UNLESS REGISTERED UNDER THE SECURITIES ACT AND ANY
                APPLICABLE STATE SECURITIES LAWS OR PURSUANT TO
                AVAILABLE EXEMPTIONS FROM SUCH REGISTRATION,
                PROVIDED THAT THE SELLER DELIVERS TO THE COMPANY AN
                OPINION OF COUNSEL SATISFACTORY TO THE COMPANY
                CONFIRMING THE AVAILABILITY OF SUCH EXEMPTION.
                INVESTORS SHOULD BE AWARE THAT THEY MAY BE REQUIRED
                TO BEAR THE FINANCIAL RISKS OF THIS INVESTMENT FOR
                AN INDEFINITE PERIOD OF TIME.

         I further agree that the Company may place stop orders on the
certificates evidencing the Stock with the transfer agent, if any, to the same
effect as the above legend. The legend and stop transfer notice referred to
above shall be removed only upon my furnishing to the Company an opinion of
counsel (reasonably satisfactory to the Company) to the effect that such legend
may be removed.

Date:                                        Signed:
     ---------------------------                    ----------------------------
Address:
        ------------------------

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

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




                                       8
<PAGE>   9
                                   EXHIBIT B

                                   ASSIGNMENT

         (To be Executed by the Holder to Effect Transfer of the Within Warrant)

         For Value Received __________________________ hereby sells, assigns and
transfers to _____________________________ this Warrant and the rights
represented hereby to purchase _________ shares of Common Stock in accordance
with the terms and conditions hereof, and does hereby irrevocably constitute and
appoint _____________________________ as attorney to transfer this Warrant on
the books of the Company with full power of substitution.



Date:                                Signed:
     ---------------------------            ------------------------------------
Please print or typewrite name       Please insert Social Security or their
and address of assignee:             Tax Identification Number of Assignee:

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

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

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                                       9