<PAGE>

                                                                     Exhibit 4.4

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, AND MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE
ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT WITH RESPECT TO THE SECURITIES
UNDER SAID ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH
REGISTRATION IS NOT REQUIRED.

THIS WARRANT IS SUBJECT TO THE TERMS AND CONDITIONS OF THAT CERTAIN SUBSCRIPTION
AGREEMENT, BETWEEN THE COMPANY AND THE HOLDER, DATED ________ __, 2000.

                       Warrant to Purchase Common Stock

                                      of

                              Endorex CORPORATION

No. CSW-___                                Date of Issuance - _________ __, 2000

          This certifies that, for value received, _____________________, or its
registered assigns ("Holder") is entitled, subject to the terms set forth below,
to purchase from Endorex Corporation, a Delaware corporation (the "Company"),
_________ shares of the Common Stock of the Company (the "Common Stock"), as
constituted on the date hereof (the "Warrant Issue Date"), upon surrender
hereof, at the principal office of the Company referred to below, with the
Notice of Exercise form attached hereto duly executed, and simultaneous payment
therefor in lawful money of the United States at the Exercise Price as set forth
in Section 2 below. The number of such shares of Common Stock are subject to
adjustment as provided below. The term "Warrant" as used herein shall include
this Warrant and any warrants delivered in substitution or exchange therefor as
provided herein. This Warrant is issued in connection with the transactions
described in that certain Subscription Agreement between the Company and the
Subscribers described therein, dated as of _________ ___, 2000, as the same may
from time to time be amended, modified or supplemented (the "Purchase
Agreement"). The Holder is subject to certain restrictions set forth in the
Purchase Agreement and shall be entitled to certain rights and privileges set
forth in the Purchase Agreement. This Warrant is one of the Warrants referred to
as the "Warrants" in the Purchase Agreement.

          1.   Term of Warrant. Subject to the terms and conditions set forth
herein, this Warrant shall be exercisable, in whole or in part, at any time
prior to __________ __, 2005.

          2.   Exercise Price. The exercise price at which this Warrant may be
exercised shall be ____________ ($______) per share of Common Stock (the
"Exercise Price").


<PAGE>

          3.   Exercise of Warrant.

               a. The purchase rights represented by this Warrant are
exercisable by the Holder in whole or in part, but not for less than 5,000
shares (unless the number of shares underlying this Warrant is less than 5,000,
in which case the Warrant shall be exercisable for such lesser number), at any
time, or from time to time, during the term hereof as described in Section 1
above, by the surrender of this Warrant and the Notice of Exercise annexed
hereto as Exhibit A duly completed and executed on behalf of the Holder, at the
office of the Company (or such other office or agency of the Company as it may
designate by notice in writing to the Holder at the address of the Holder
appearing on the books of the Company), together with payment in immediately
available funds or by check acceptable to the Company in an amount equal to the
product of the Exercise Price set forth in Section 2 above multiplied by the
number of shares of Common Stock being purchased upon such exercise.

               b.   This Warrant shall be deemed to have been exercised
immediately prior to the close of business on the date of its surrender for
exercise as provided above, and the person entitled to receive the shares of
Common Stock issuable upon such exercise shall be treated for all purposes as
the holder of record of such shares as of the close of business on such date. As
promptly as practicable on or after such date and in any event within ten (10)
days thereafter, the Company at its expense shall issue and deliver to the
person or persons entitled to receive the same a certificate or certificates
representing the number of shares issuable upon such exercise. In the event that
this Warrant is exercised in part, the Company at its expense will also execute
and deliver a new Warrant of like tenor exercisable for the number of shares for
which this Warrant may then be exercised.

          4.   No Fractional Shares or Scrip. No fractional shares or scrip
representing fractional shares shall be issued upon the exercise of this
Warrant. In lieu of any fractional share to which the Holder would otherwise be
entitled, the Company shall make a cash payment equal to the Exercise Price
multiplied by such fraction.

          5.   Replacement of Warrant. On receipt of evidence reasonably
satisfactory to the Company of the loss, theft, destruction, or mutilation of
this Warrant and, in the case of loss, theft, or destruction, on delivery of an
indemnity agreement reasonably satisfactory in form and substance to the Company
or, in the case of mutilation, on surrender and cancellation of this Warrant,
the Company, at its expense, shall execute and deliver, in lieu of this Warrant,
a new warrant of like tenor and amount.

          6.   Rights of Stockholders. This Warrant shall not entitle the Holder
to any of the rights of a stockholder of the Company.

          7.   Transfer of Warrant.

               a.   Warrant Register. The Company will maintain a register (the
"Warrant Register") containing the names and addresses of the Holder or Holders.
Any Holder of this Warrant or any portion thereof may change his or its address
as shown on the Warrant Register by written notice to the Company requesting
such change. Any notice or written communication required or permitted to be
given to the Holder may be delivered or given by


<PAGE>

mail to such Holder in the name as shown on the Warrant Register and at the
address shown on the Warrant Register. Until this Warrant is transferred on the
Warrant Register of the Company, the Company may treat the Holder as shown on
the Warrant Register as the absolute owner of this Warrant for all purposes,
notwithstanding any notice to the contrary.

               b.   Transferability and Nonnegotiability of Warrant. This
Warrant may not be transferred or assigned in whole or in part without
compliance with all applicable federal and state securities laws by the
transferor and the transferee (including the delivery of investment
representation letters and legal opinions reasonably satisfactory to the
Company, if such are requested by the Company) and in compliance with subsection
(e) below. Subject to the provisions of this Warrant with respect to compliance
with the Securities Act of 1933, as amended (the "Act"), and further subject to
the requirement that any transferee must first agree in writing, in a form
reasonably acceptable to the Company, to be bound by the terms of the Purchase
Agreement, and exhibits thereto, title to this Warrant may be transferred by
endorsement (by the Holder executing the Assignment Form annexed hereto as
Exhibit B) and delivery in the same manner as a negotiable instrument
transferable by endorsement and delivery. The Common Stock to be issued upon
exercise hereof may not be transferred or assigned in whole or in part without
compliance with all applicable federal and state securities laws by the
transferor and the transferee (including the delivery of investment
representation letters and legal opinions reasonably satisfactory to the
Company, if such are requested by the Company).

               c.   Exchange of Warrant Upon a Transfer. On surrender of this
Warrant for exchange, properly endorsed for transfer on the Assignment Form, and
subject to the provisions of this Warrant with respect to compliance with the
Act and with the limitations on assignments and transfers contained in this
Section 7, the Company, at its expense, shall issue to or on the order of the
Holder a new warrant or warrants of like tenor, in the name of the Holder or as
the Holder (on payment by the Holder of any applicable transfer taxes) may
direct, for the number of shares issuable upon exercise thereof.

               d.   Compliance with Securities Laws.

                    (1)  The Holder of this Warrant, by acceptance hereof,
acknowledges that this Warrant and the shares of Common Stock to be issued upon
exercise hereof are being acquired solely for the Holder's own account and not
as a nominee for any other party, and for investment, and that the Holder will
not offer, sell, or otherwise dispose of this Warrant or any shares of Common
Stock to be issued upon exercise hereof except under circumstances that will not
result in a violation of the Act or any state securities laws. Upon exercise of
this Warrant, the Holder shall, if requested by the Company, confirm in writing,
in a form satisfactory to the Company, that the shares of Common Stock so
purchased 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, except under circumstances that will not result in a
violation of the Act or any state securities laws.

                    (2)  This Warrant and all shares of Common Stock issued upon
exercise hereof shall be stamped or imprinted with a legend in substantially the
following form (in addition to any legend required by state securities laws):


                                       3

<PAGE>

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, AND MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE
ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT WITH RESPECT TO THE SECURITIES
UNDER SAID ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH
REGISTRATION IS NOT REQUIRED.

     8. Reservation of Stock. The Company covenants that during the term this
Warrant is exercisable, the Company will reserve from its authorized and
unissued Common Stock a sufficient number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant and, from time to time, will
take all steps necessary to amend its Restated Certificate of Incorporation, as
amended from time to time (the "Certificate"), to provide sufficient reserves of
shares of Common Stock issuable upon exercise of the Warrant. The Company
further covenants that all shares that may be issued upon the exercise of rights
represented by this Warrant, upon exercise of the rights represented by this
Warrant and payment of the Exercise Price, all as set forth herein, will be free
from all taxes, liens, and charges in respect of the issue thereof (other than
taxes in respect of any transfer occurring contemporaneously or otherwise
specified herein), and will be fully paid and nonassessable. The Company agrees
that its issuance of this Warrant shall constitute full authority to its
officers who are charged with the duty of executing stock certificates to
execute and issue the necessary certificates for shares of Common Stock upon the
exercise of this Warrant.

     9. Notices.

          a. Whenever the Exercise Price or number of shares purchasable
hereunder shall be adjusted pursuant to Section 10 hereof, the Company shall
issue a certificate signed by its Treasurer setting forth, in reasonable detail,
the event requiring the adjustment, the amount of the adjustment, the method by
which such adjustment was calculated and the Exercise Price and number of shares
purchasable hereunder after giving effect to such adjustment, and shall cause a
copy of such certificate to be mailed (by first class mail, postage prepaid) to
the Holder of this Warrant as provided in Section 12.1 hereof.

          b. In case

               (1) the Company shall take a record of the holders of its Common
Stock (or other stock or securities at the time receivable upon the exercise of
this Warrant) for the purpose of entitling them to receive any dividend or other
distribution, or any right to subscribe for or purchase any shares of stock of
any class or any other securities, or to receive any other right, or

               (2) the Company shall consummate any reorganization,
reclassification, combination, exchange or subdivision of the capital stock of
the Company, any consolidation or merger of the Company with or into another
corporation, or any conveyance of all or substantially all of the assets of the
Company to another corporation, or

               (3) of any voluntary dissolution, liquidation or winding-up of
the Company,

                                       4
<PAGE>

then, and in each such case, the Company will mail or cause to be mailed to the
Holder or Holders a notice specifying, as the case may be, (A) 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
(B) the date on which such reorganization, reclassification, combination,
exchange, subdivision, 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 stock or securities
at the time receivable upon the exercise of this Warrant) 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, combination, exchange, subdivision, consolidation, merger,
conveyance, dissolution, liquidation or winding-up. Such notice shall be mailed
at least twenty (20) business days prior to the date therein specified.

          c. All such notices, advices and communications shall be deemed to
have been received (i) in the case of personal delivery, on the date of such
delivery and (ii) in the case of mailing, on the third (3) business day
following the date of such mailing.

     10. Adjustments. The number of shares purchasable hereunder are subject to
adjustment from time to time as follows:

          10.1. Merger, Sale of Assets, Etc.

          a. If at any time, while this Warrant, or any portion thereof, remains
outstanding and unexpired there shall be (i) a reorganization (other than a
combination, reclassification, exchange or subdivision of shares otherwise
provided for herein), (ii) a merger or consolidation of the Company with or into
another corporation in which the Company is not the surviving entity, or a
reverse triangular merger in which the Company is the surviving entity but the
shares of the Company's capital stock outstanding immediately prior to the
merger are converted by virtue of the merger into other property, whether in the
form of securities, cash, or otherwise, or (iii) a sale or transfer of
substantially all of the Company's properties and assets to any other person,
then, as a part of such reorganization, merger, consolidation, sale or transfer,
lawful provision shall be made so that the holder of this Warrant shall
thereafter be entitled to receive upon exercise of this Warrant, during the
period specified herein and upon payment of the Exercise Price then in effect in
the manner set forth in Section 3, the number of shares of stock or other
securities or property of the successor corporation resulting from such
reorganization, merger, consolidation, sale or transfer which a holder of the
shares deliverable upon exercise of this Warrant would have been entitled to
receive in such reorganization, merger, consolidation, sale or transfer if this
Warrant had been exercised immediately before such reorganization, merger,
consolidation, sale or transfer, all subject to further adjustment as provided
in this Section 10. The foregoing provisions of this Section 10.1 shall
similarly apply to successive reorganizations, consolidations, mergers, sales
and transfers and to the stock or securities of any other corporation which are
at the time receivable upon the exercise of this Warrant. If the per share
consideration payable to the holder hereof for shares in connection with any
such transaction is in a form other than cash or marketable securities, then the
value of such consideration shall be determined in good faith by the Company's
Board of Directors. In all events, appropriate adjustment (as determined in good
faith by the Company's Board of Directors) shall be made in the application of
the provisions of this Warrant with respect to the

                                       5
<PAGE>

rights and interests of the Holder after the transaction, to the end that the
provisions of this Warrant shall be applicable after that event, as near as
reasonably may be, in relation to any shares or other property deliverable after
that event upon exercise of this Warrant.

          b. Notices of Record Date. In the event that the Company shall propose
at any time to merge with or into any other corporation, or sell, lease or
convey all or substantially all its property or business, or to liquidate,
dissolve or wind up, then the Company shall send to the holder of this Warrant
at least twenty (20) business days' prior written notice of the date on which a
record shall be taken for determining rights to vote in respect of such event.

          10.2. Reclassification, etc. If the Company at any time while this
Warrant, or any portion thereof, remains outstanding and unexpired shall, by
reclassification of securities or otherwise, change any of the securities as to
which purchase rights under this Warrant exist into the same or a different
number of securities of any other class or classes, this Warrant shall
thereafter represent the right to acquire such number and kind of securities as
would have been issuable as the result of such change with respect to the
securities which were subject to the purchase rights under this Warrant
immediately prior to such reclassification or other change, and the Exercise
Price therefor shall be appropriately adjusted, all subject to further
adjustment as provided in Section 10.

          10.3. Split, Subdivision or Combination of Shares. If the Company at
any time while this Warrant, or any portion hereof, remains outstanding and
unexpired shall split, subdivide or combine the securities as to which purchase
rights under this Warrant exist, into a different number of securities of the
same class, the number of shares of such securities available for purchase in
effect immediately prior to such subdivision, combination, or dividend or other
distribution and the Exercise Price per share for such securities shall be
proportionately adjusted. Adjustments set forth herein shall be readjusted in
the same manner for any successive event or events described herein.

          10.4. Adjustments for Dividends in Stock or Other Securities or
Property. If while this Warrant, or any portion thereof, remains outstanding and
unexpired the holders of the securities as to which purchase rights under this
Warrant exist at the time shall have received, or, on or after the record date
fixed for the determination of eligible stockholders, shall have become entitled
to receive, without payment therefor, other or additional stock or other
securities or property (other than cash) of the Company by way of dividend,
then, and in each case, this Warrant shall represent the right to acquire, in
addition to the number of shares of the security receivable upon exercise of
this Warrant, and without payment of any additional consideration therefor, the
amount of such other or additional stock or other securities or property (other
than cash) of the Company which such holder would hold on the date of such
exercise had it been the holder of record of the security receivable upon
exercise of this Warrant on the date hereof and had thereafter, during the
period from the date hereof to and including the date of such exercise, retained
such shares and/or all other additional stock available to it as aforesaid
during such period, giving effect to all adjustments called for during such
period by the provisions of this Section 10.

          10.5. Certificate as to Adjustments. Upon the occurrence of each
adjustment or readjustment pursuant to this Section 10, the Company, at its
expense, shall

                                       6
<PAGE>

promptly compute such adjustment or readjustment in accordance with the terms
hereof and furnish to each Holder of this Warrant a certificate setting forth
such adjustment or readjustment and showing in detail the facts upon which such
adjustment or readjustment is based. The Company shall, upon the written
request, at any time, of any such Holder, furnish or cause to be furnished to
such Holder a like certificate setting forth: (i) such adjustments and
readjustments; (ii) the Exercise Price at the time in effect; and (iii) the
number of shares and the amount, if any, of other property which at the time
would be received upon the exercise of this Warrant.

          10.6. No Impairment. The Company will not, by any 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 10 and in
the taking of all such action as may be necessary or appropriate in order to
protect the rights of the holders of this Warrant against impairment.

     11. Miscellaneous.

          11.1. Notices. Any notices required to be sent to a Holder will be
delivered to the address of such Holder shown on the books of the Company. All
notices referred to herein will be delivered in person or sent by first class
mail, postage prepaid, and will be deemed to have been given when so delivered
or sent unless otherwise provided herein.

          11.2. Descriptive Headings; Governing Law. The descriptive headings of
the paragraphs of this Warrant are inserted for convenience only and do not
constitute a part of this Warrant. The construction, validity and interpretation
of this Warrant will be governed by the laws of the State of New York, without
regard to principles of conflicts or choice of law.

     IN WITNESS WHEREOF, ENDOREX CORPORATION caused this Warrant to be executed
by its officer thereunto duly authorized.

Dated: April 12, 2000
                                 ENDOREX CORPORATION


                                 By:
                                    --------------------------------------
                                    Michael S. Rosen
                                    President and Chief Executive Officer
CSW00-17

                                       7
<PAGE>

                                   EXHIBIT A
                                   ---------

                          FORM OF NOTICE OF EXERCISE
                          --------------------------

To: ENDOREX CORPORATION

     (1) Pursuant to the terms of the attached Warrant, the undersigned hereby
elects to purchase ___________ shares of Common Stock of ENDOREX CORPORATION
pursuant to the terms of the attached Warrant, and tenders herewith payment of
the Exercise Price of such shares in full.

     (2) In exercising this Warrant, the undersigned hereby confirms and
acknowledges that the shares of Common Stock are being acquired solely for the
account of the undersigned and not as a nominee for any other party, and for
investment, and that the undersigned will not offer, sell, or otherwise dispose
of any such shares of Common Stock except under circumstances that will not
result in a violation of the Securities Act of 1933, as amended, or any state
securities laws.

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

                         ______________________________
                                     [Name]

                         ______________________________
                                     [Name]

     (4) Please issue a new Warrant for the unexercised portion of the attached
Warrant in the name of the undersigned or in such other name as is specified
below:

                         ______________________________
                                     [Name]


----------                              ----------------------------
[Date]                                  [Signature]
<PAGE>

                                   EXHIBIT B
                                   ---------

                            FORM OF ASSIGNMENT FORM
                            -----------------------

     FOR VALUE RECEIVED, the undersigned registered owner of this Warrant hereby
sells, assigns and transfers unto the Assignee named below all of the rights of
the undersigned under the within Warrant, with respect to the number of shares
of Common Stock set forth below:

Name of Assignee            Address               No. of Shares
----------------            --------              -------------


and does hereby irrevocably constitute and appoint ___________________________
Attorney to make such transfer on the books of ENDOREX CORPORATION maintained
for the purpose, with full power of substitution in the premises.

     The undersigned also represents that, by assignment hereof, the Assignee
acknowledges that this Warrant and the shares of stock to be issued upon
exercise hereof are being acquired for investment and that the Assignee will not
offer, sell or otherwise dispose of this Warrant or any shares of stock to be
issued upon exercise hereof except under circumstances which will not result in
a violation of the Securities Act of 1933, as amended, or any state securities
laws. Further, the Assignee has acknowledged that upon exercise of this Warrant,
the Assignee shall, if requested by the Company, confirm in writing, in a form
satisfactory to the Company, that the shares of stock so purchased are being
acquired for investment and not with a view toward distribution or resale.


DATED:  ____________________


                                   ___________________________________
                                           Signature of Holder

                                   ___________________________________
                                                (Witness)