<PAGE>


                                                                EXHIBIT 4.2

                                  WARRANT AGREEMENT

         THIS WARRANT AGREEMENT dated as of March 28, 1997 (as amended,
supplemented or modified from time to time, the "WARRANT AGREEMENT") by and
among SUNPHARM CORPORATION, a Delaware corporation (the "ISSUER"), and THE
PURCHASERS EXECUTING A COUNTERPART SIGNATURE PAGE HERETO (individually, a
"PURCHASER" and, collectively, the "PURCHASERS").

                                 W I T N E S S E T H:

         WHEREAS, pursuant to a Unit Purchase Agreement dated as of the date
hereof (as the same may be amended, supplemented or otherwise modified from time
to time, the "PURCHASE AGREEMENT") by and among the Issuer and the Purchasers,
the Issuer has issued to the Purchasers units (the "UNITS"), each Unit
consisting of one share of Common Stock (as defined below) and one of the
Warrants hereinafter described;

         NOW, THEREFORE, in consideration of the premises the parties hereto
agree as follows:

    Section 1.     Definitions. (a) As used in this Warrant Agreement, unless
otherwise defined herein, terms defined in the Purchaser Agreement shall have
such defined meanings when used herein and the following terms shall have the
following meanings, unless the context otherwise requires:

         "AFFILIATE" shall have the meaning given to such term in Rule 12b-2 of
the Rules and Regulations under the Exchange Act.

         "CALCULATED DIFFERENCE" as of any date of determination shall mean,
with respect to any conversion or exercise of a Warrant, an amount equal to the
difference between (i) the Current Market Price Per Share as of such date and
(ii) $4.00.  

         "CLOSING DATE" shall have the meaning given such term in the Purchase
Agreement.

         "COMMISSION" shall mean the Securities and Exchange Commission or any
entity succeeding to any or all of its functions under the Securities Act and
the Exchange Act.

         "COMMON STOCK" shall mean the Common Stock, par value $.0001 per
share, of the Issuer, and shall include any stock into which such Common Stock
shall have been changed or any stock resulting from any reclassification of such
Common Stock and all other stock of any class or classes (however designated) of
the Issuer the registered holders of which have the right, without limitation as
to amount, either to all or to a share of the balance of current dividends and
liquidating dividends after the payment of dividends and distributions on any
shares entitled to preference.


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<PAGE>

         "CONVERSION DATE" has the meaning given such term in Section 6(b).

         "CURRENT MARKET PRICE PER SHARE" of the Common Stock on any date shall
mean the average of the daily closing prices per share of Common Stock for the
20 consecutive Trading Days immediately prior to such date; PROVIDED that in the
event that the current market price per share of Common Stock is determined
during a period following the announcement by the Company of (A) a dividend or
distribution on the Common Stock payable in shares of Common Stock or securities
convertible into shares of Common Stock or (B) any subdivision, combination or
reclassification of the Common Stock and prior to the expiration of 20 Trading
Days after the ex-dividend date for such dividend or distribution, or the record
date for such subdivision, combination or reclassification, then, and in each
such case, the Current Market Price Per Share shall be appropriately adjusted to
reflect ex-dividend trading or such subdivision, combination or
reclassification.  The closing price for each day shall be (i) if the Common
Stock is then quoted on the Nasdaq National Market, the Nasdaq Small Cap Market
or another primary national securities exchange, the closing bid price of the
Common Stock as reported by the Nasdaq National Market, the Nasdaq Small Cap
Market or such primary national securities exchange (as the case may be), (ii)
if the Common Stock is not then traded on the Nasdaq National Market, the Nasdaq
Small Cap Market nor on a national securities exchange, the closing bid price in
the over-the-counter market as reported by the National Association of
Securities Dealers' Automated Quotation System or, if not so reported, the price
as reported by the National Quotation Bureau, Inc., or any organization
performing a similar function or (iii) if no such prices are then furnished, the
fair market value of a share of Common Stock as reasonably determined by the
Board of Directors of the Issuer and reasonably acceptable to the holders of a
majority of the Warrants.

         "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934, as
amended, or any successor federal statute.

         "EXERCISE PRICE" shall mean the exercise price of a Warrant, which
shall be equal to the sum of (i) $4.00, PLUS (ii) an amount equal to the product
of (A) 0.40, in the case of any conversion of a Warrant pursuant to Section 6(b)
or, 0.30, in the case of any other exercise of a Warrant pursuant to this
Warrant Agreement, TIMES (B) the Calculated Difference as of the date of the
notice of conversion or exercise of such Warrant; PROVIDED that in no event
shall the Exercise Price be less than $4.00.

         "EXPIRATION DATE" shall mean March 28, 2002.

         "NON-PUBLIC WARRANT SHARES" shall mean Warrant Shares that have not
been sold to the public and bear the legend set forth in subsection 14(b).

         "NON-SURVIVING COMBINATION" shall mean any merger, consolidation or
other business combination by the Issuer with one or more Persons in which the
Issuer is not the survivor, or a sale of all or substantially all of the assets
of the Issuer to one or more such other Persons.


                                      -2-


<PAGE>

         "SECURITIES ACT" shall mean the Securities Act of 1933, as amended, or
any successor federal statute and the rules and regulations of the Commission
thereunder, all as the same may be in effect from time to time.

         "TRADING DAY" means a day on which the principal national securities
exchange on which the Common Stock is listed or admitted to trading is open for
the transaction of business or, if the Common Stock is not listed or admitted to
trading on any national securities exchange, a Business Day.

         "WARRANT CERTIFICATE" shall mean a certificate evidencing one or more
Warrants, substantially in the form of Exhibit A attached hereto, with such
changes therein as may be required to reflect any adjustments made pursuant to
Section 12.

         "WARRANT HOLDERS" shall mean the Purchasers or any Affiliates thereof
and such other Persons to whom Purchasers or an Affiliate thereof transfers
Warrants in compliance with the terms of this Warrant Agreement.

         "WARRANT OFFICE" shall mean the office or agency of the Issuer at
which the Warrant Register shall be maintained and where the Warrants may be
presented for exercise, exchange, substitution and transfer, which office or
agency will be the office of the Issuer at 4651 Salisbury Road, Jacksonville, FL
33256, which office or agency may be changed by the Issuer pursuant to notice in
writing to the Persons named in the Warrant Register as the holders of the
Warrants.

         "WARRANT REGISTER" shall mean the register, substantially in the form
of Exhibit B attached hereto, maintained by the Issuer at the Warrant Office.

         "WARRANT SHARES" shall mean the shares of Common Stock issued or
issuable upon exercise of the Warrants as the number of such shares may be
adjusted from time to time pursuant to Section 12 and the provisions of the
Issuer's Articles of Incorporation.

         "WARRANTS" shall mean the stock purchase warrants issued pursuant to
this Warrant Agreement entitling the record holders thereof to purchase from the
Issuer at the Warrant Office an aggregate of 1,828,286 shares of Common Stock,
subject to adjustment as provided in Section 12, at the Exercise Price at any
time after the Closing Date and before 5:00 P.M., New York time, on the
Expiration Date; individually, a "Warrant."

    (b)  For all purposes of this Warrant Agreement, except as otherwise
expressly provided or unless the context otherwise requires:

         (i)  "Herein", "hereof" and "hereunder" and other words of similar
    import refer to this Warrant Agreement as a whole and not to any particular
    Section or other subdivision;

         (ii) Any uses of the masculine, feminine or neuter gender shall also
    be deemed to include any other gender as appropriate;


                                      -3-


<PAGE>

         (iii)     The exhibits and schedules to this Warrant Agreement shall
    be deemed an integral part of this Warrant Agreement;

         (iv) Except as specifically set forth in such representation, each of
    the representations and warranties of the Issuer in Section 3 hereof is
    separate and is not limited, qualified or modified by the existence,
    wording or satisfaction of any other representation of the Issuer in
    Section 3 or otherwise;

         (v)  All references herein (in covenants or otherwise) to any
    action(s) which are to be taken (or which are prohibited from being taken)
    by any Person, the Issuer or any Subsidiary shall apply to such Person, the
    Issuer or such Subsidiary, as the case may be, whether such action is taken
    directly or indirectly; and

         (vi) All references herein to actions by the Issuer or any Subsidiary
    (including, without limitation, actions denoted by terms such as "create",
    "sell", "transfer" or "dispose of") mean such action whether voluntary or
    involuntary, by operation of law or otherwise.

    Section 2.     ISSUANCE OF WARRANTS.  The Issuer hereby agrees to issue and
deliver to the Purchasers or, at the option of a Purchaser, an Affiliate
thereof, on the Closing Date, the Warrants and one or more Warrant Certificates
evidencing the Warrants.  No payment shall be required from any Purchaser or its
Affiliate in consideration of its receipt of the Warrants.

    Section 3.     REPRESENTATIONS AND WARRANTIES.  The Issuer hereby
represents and warrants to the Purchasers,  for the benefit of the Purchasers
and any other Warrant Holder, as follows:

    (a)  The Issuer is a corporation duly incorporated, validly existing and in
good standing under the laws of the State of Delaware, has the corporate power
and authority to conduct its business as presently conducted and as intended to
be conducted, has the corporate power and authority to execute and deliver this
Warrant Agreement and the Warrant Certificates, to issue the Warrants and to
perform its obligations under this Warrant Agreement and the Warrant
Certificates, has the corporate power and authority and legal right to own and
lease its properties and is duly qualified and in good standing as a foreign
corporation in each jurisdiction in which it owns or leases real property or in
which the conduct of its business requires such qualification, except where
failure to be so qualified could not be reasonably expected to have a material
adverse effect on the business, properties, financial condition or results of
operations of the Issuer and its Subsidiaries taken as a whole.

    (b)  The execution, delivery and performance by the Issuer of this Warrant
Agreement and the Warrant Certificates, the issuance of the Warrants and the
issuance of the Warrant Shares upon the exercise of the Warrants have been duly
authorized by all necessary corporate action and do not and will not violate, or
result in a breach of, or constitute a default under, or require any consent
under, or result in the creation of any lien, charge or encumbrance upon the
assets of the Issuer pursuant to, any law, statute, ordinance, rule, regulation,
order or decree of any court, governmental body or regulatory authority or
administrative agency having jurisdiction over the Issuer or its


                                      -4-


<PAGE>

Subsidiaries or the Issuer's Articles of Incorporation or any contract, 
mortgage, loan agreement, note, lease or other instrument binding upon the 
Issuer or its Subsidiaries or by which their properties are bound.



    (c)  This Warrant Agreement has been duly executed and delivered by the
Issuer and constitutes a legal, valid, binding and enforceable obligation of the
Issuer.  When the Warrants and Warrant Certificates have been issued as
contemplated hereby, (i) the Warrants and the Warrant Certificates will
constitute legal, valid, binding and enforceable obligations of the Issuer and
(ii) the Warrant Shares, when issued upon exercise of the Warrants in accordance
with the terms hereof will be duly authorized, validly issued, fully paid and
nonassessable shares of the Common Stock with no personal liability attaching to
the ownership thereof.

    Section 4.     REGISTRATION, TRANSFER AND EXCHANGE OF CERTIFICATES.

    (a)  The Issuer shall maintain, at the Warrant Office, the Warrant Register
for registration of the Warrants and Warrant Certificates and transfers thereof.
On the Closing Date, the Issuer shall register the Warrants and Warrant
Certificates in the Warrant Register in the name of the Warrant Holders.  The
Issuer may deem and treat the registered holders of the Warrant Certificates as
the absolute owners thereof and the Warrants represented thereby
(notwithstanding any notation of ownership or other writing on the Warrant
Certificates made by any person) for the purpose of any exercise thereof or any
distribution to the holders thereof, and for all other purposes, and the Issuer
shall not be affected by any notice to the contrary.

    (b)  Subject to Section 14, the Issuer shall register the transfer of any
outstanding Warrants in the Warrant Register upon surrender of the Warrant
Certificates evidencing such Warrants to the Issuer at the Warrant Office,
accompanied (if so required by it) by a written instrument or instruments of
transfer in form satisfactory to it, duly executed by the registered holder or
holders thereof or by the duly appointed legal representative thereof.  Upon any
such registration of transfer, new Warrant Certificates evidencing such
transferred Warrants shall be issued to the transferee and the surrendered
Warrant Certificates shall be canceled.  If less than all the Warrants evidenced
by Warrant Certificates surrendered for transfer are to be transferred, new
Warrant Certificates shall be issued to the holder surrendering such Warrant
Certificates evidencing such remaining number of Warrants.

    (c)  Warrant Certificates may be exchanged at the option of the holders
thereof, when surrendered to the Issuer at the Warrant Office, for another
Warrant Certificate or other Warrant Certificates of like tenor and representing
in the aggregate a like number of Warrants.  Warrant Certificates surrendered
for exchange shall be canceled.

    (d)  No charge shall be made for any such transfer or exchange except for
any tax or other governmental charge imposed in connection therewith.  Except as
provided in subsection 14(b) each


                                      -5-


<PAGE>

Warrant Certificate issued upon transfer or exchange shall bear the legend set 
forth in subsection 14(b) if the Warrant Certificate presented for transfer or 
exchange bore such legend.

    Section 5.     MUTILATED OR MISSING WARRANT CERTIFICATES.  If any Warrant
Certificate shall be mutilated, lost, stolen or destroyed, the Issuer shall
issue, in exchange and substitution for and upon cancellation of the mutilated
Warrant Certificate, or in lieu of and substitution for the Warrant Certificate
lost, stolen or destroyed, a new Warrant Certificate of like tenor and
representing an equivalent number of Warrants, but only upon receipt of evidence
satisfactory to the Issuer of such loss, theft or destruction of such Warrant
Certificate.  No service charge shall be made for any such substitution, but all
stamp, tax and other governmental duties that may be imposed in relation thereto
shall be borne by the holder of such Warrant Certificate.  Each Warrant
Certificate issued in any such substitution shall bear the legend set forth in
subsection 14(b) if the Warrant Certificate for which such substitution was made
bore such legend.

    Section 6.     DURATION AND EXERCISE OF WARRANTS.

    (a)  The Warrants evidenced by a Warrant Certificate shall be exercisable
in whole or in part by the registered holder thereof on any Business Day after
the Closing Date and on or before 5:00 P.M., New York time, on the Expiration
Date.

    (b)  Subject to the provisions of this Warrant Agreement, the Warrants
evidenced by a Warrant Certificate may be exercised by the registered holder
thereof by the surrender of the Warrant Certificate evidencing the Warrants to
be exercised, with the form of election to purchase on the reverse thereof or
attached thereto duly completed and signed, to the Issuer at the Warrant Office,
and upon payment of the aggregate Exercise Price for the number of Warrant
Shares in respect of which such Warrants are being exercised in lawful money of
the United States of America and/or by surrender to the Issuer of shares of
Common Stock then owned by the Warrant Holder and valued for purposes hereof at
their Current Market Price Per Share at the time of exercise.  In lieu of
exercising Warrants pursuant to the immediately preceding sentence, the Warrant
Holder shall have the right to require the Issuer to convert the Warrants, in
whole or in part and at any time or times (the "Conversion Right"), into Warrant
Shares, by surrendering to the Issuer the Warrant Certificate evidencing the
Warrants to be converted, accompanied by the form of conversion notice on the
reverse thereof or attached thereto which has been duly completed and signed. 
Upon exercise of the Conversion Right, the Issuer shall deliver to the Warrant
Holder (WITHOUT payment by the Warrant Holder of any Exercise Price) that number
of Warrant Shares which is equal to the quotient obtained by dividing (x) the
value of the number of Warrants being converted at the time the Conversion Right
is exercised (determined by subtracting the aggregate Exercise Price for all
such Warrants immediately prior to the exercise of the Conversion Right from the
aggregate current market price (determined on the basis of the Current Market
Price Per Share on the date (the "CONVERSION DATE") that the Issuer receives the
Warrant Certificate evidencing the Warrants to be converted accompanied by the
form of conversion notice on the reverse thereof or attached thereto which has
been duly completed and signed) of that number of Warrant Shares purchasable
upon exercise of such Warrants on the Conversion Date (taking into account all
applicable adjustments pursuant to Section 12) by (y) the Current Market Price
Per Share on the Conversion Date.  Any references in this Warrant


                                      -6-


<PAGE>

Agreement to the "exercise" of any Warrants, and the use of the term "exercise" 
herein, shall be deemed to include (without limitation) any exercise of the 
Conversion Right.  Any exercise of a Warrant hereunder may be made subject to 
the satisfaction of one or more conditions (including, without limitation, the 
consummation of a sale of the capital stock of the Issuer or a merger or other 
business combination involving the Issuer) which are set forth in a writing 
which is made a part of or is appended to the aforementioned form of election 
to purchase or conversion notice (as the case may be) by the Warrant Holder.

    (c)  Upon exercise of any Warrants hereunder, the Issuer shall issue and
cause to be delivered to or upon the written order of the registered holders of
such Warrants and in such name or names as such registered holders may
designate, a certificate for the Warrant Share or Warrant Shares issued upon
such exercise of such Warrants.  Any Persons so designated to be named therein
shall be deemed to have become holders of record of such Warrant Share or
Warrant Shares as of the date of exercise of such Warrants.

    (d)  If less than all of the Warrants evidenced by a Warrant Certificate
are exercised at any time, a new Warrant Certificate or Certificates shall be
issued for the remaining number of Warrants evidenced by such Warrant
Certificate.  Each new Warrant Certificate so issued shall bear the legend set
forth in subsection 14(b) if the Warrant Certificate presented in connection
with partial exercise thereof bore such legend unless the transfer restrictions
referred to in such legend are no longer applicable pursuant to subsection
14(d).  All Warrant Certificates surrendered upon exercise of Warrants shall be
canceled.

    Section 7.     NO FRACTIONAL SHARES.  The Issuer shall not be required to
issue fractional shares of Common Stock upon exercise of the Warrants but shall
pay for any such fraction of a share an amount in cash equal to the then Current
Market Price Per Share of one share of Common Stock multiplied by such fraction.

    Section 8.     PAYMENT OF TAXES.  The Issuer will pay all taxes
attributable to the initial issuance of Warrant Shares upon the exercise of the
Warrants, PROVIDED that the Issuer shall not be required to pay any tax which
may be payable in respect of any transfer involved in the issue of any Warrant
Certificate or any certificate for Warrant Shares in a name other than that of
the registered holder of a Warrant Certificate surrendered upon the exercise of
a Warrant, and the Issuer shall not be required to issue or deliver such
certificate unless or until the person or persons requesting the issuance
thereof shall have paid to the Issuer the amount of such tax or shall have
established to the satisfaction of the Issuer that such tax has been paid.

    Section 9.     STOCKHOLDER RIGHTS.

    (a)  Nothing contained in this Warrant Agreement or in any of the Warrant
Certificates shall be construed as conferring upon the holders thereof the right
to vote or to consent or to receive notice as a stockholder in respect of the
meetings of stockholders or the election of directors of the Issuer or any other
matter, or any rights whatsoever as a stockholder of the Issuer.


                                      -7-


<PAGE>

    (b)  Nothing contained in this Warrant Agreement or in any of the Warrant
Certificates shall be construed as imposing any obligation on the registered
holders thereof to purchase any securities or as imposing any liabilities on
such holders as stockholders of the Issuer, whether such obligation or
liabilities are asserted by the Issuer or by creditors of the Issuer.

    Section 10.   RESERVATION AND ISSUANCE OF SHARES; CERTAIN CORPORATE ACTIONS.

    (a)  The Issuer will at all times have authorized, and reserve and keep
available, free from preemptive rights, for the purpose of enabling it to
satisfy any obligation to issue Warrant Shares upon the exercise of the
Warrants, the number of shares of Common Stock deliverable upon exercise of all
outstanding Warrants.

    (b)  The Issuer covenants that all Warrant Shares will, upon issuance in
accordance with the terms of this Warrant Agreement and the Issuer's Certificate
of Incorporation, be fully paid and nonassessable and free from all taxes
(except as otherwise contemplated in Section 8 hereof) with respect to the
issuance thereof and from all liens, charges and security interests (other than
any created by or on behalf of any Warrant Holder).

    (c)  The Issuer will not, by amendment of its Certificate of Incorporation
or through any consolidation, merger, reorganization, transfer of assets,
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
Agreement or the Warrant Certificates.  Without limiting the generality of the
foregoing, the Issuer (a) will not permit the par value or the determined or
stated value of any shares of the Issuer's Common Stock receivable upon the
exercise of the Warrants to exceed the amount payable therefor upon such
exercise, (b) will take all such action as may be necessary or appropriate in
order that the Issuer may validly and legally issue fully paid and nonassessable
shares of the Issuer's Common Stock, upon the exercise of the Warrants from time
to time outstanding, including, without limitation, amending its Certificate of
Incorporation to reduce or eliminate the par value of the Common Stock and (c)
will not take any action which results in an adjustment in the number of Warrant
Shares obtainable upon the exercise of any Warrants if the total number of
shares of the Issuer's Common Stock (or other securities) issuable after such
action upon the exercise of all of the then-outstanding Warrants would exceed
the total number of shares of the Issuer's Common Stock (or other securities)
then authorized by the Issuer's Articles of Incorporation and available for
purpose of issuance upon such exercise.

    (d)  The Issuer agrees that it will not enter into an agreement providing
for a Non-Surviving Combination or effect any such Non-Surviving Combination
unless the party to such transaction that is the surviving entity thereof or the
purchaser or purchasers of substantially all of the assets of the Issuer (the
"Survivor") (i) shall be obligated to distribute or pay to each Warrant Holder,
upon payment of the Exercise Price prior to the Expiration Date, the number of
shares of stock or other securities or other property (including any cash) of
the Survivor that would have been distributable or payable on account of the
Warrant Shares if such Warrant Holder's Warrants had been exercised immediately
prior to such Non-Surviving Combination (or, if applicable, the record date
therefor), as such number of shares or other securities or other property may
thereafter be


                                      -8-


<PAGE>

adjusted pursuant to Section 12 of this Warrant Agreement and (ii) shall assume 
by written instrument all of the obligations of the Issuer under this Warrant 
Agreement.

    Section 11.    OBTAINING OF GOVERNMENTAL APPROVALS AND STOCK EXCHANGE
LISTINGS.  Subject to the provisions of Article VII of the Purchase Agreement,
the Issuer will, at its own expense, from time to time take all action which may
be necessary to obtain and keep effective any and all permits, consents and
approvals of governmental agencies and authorities which are or become requisite
in connection with the issuance, sale, transfer and delivery of the Warrant
Certificates and the exercise of the Warrants and the issuance, sale, transfer
and delivery of the Warrant Shares and all action which may be necessary so that
such Warrant Shares, immediately upon their issuance upon the exercise of
Warrants will be listed on each securities exchange, if any, on which the Common
Stock is then listed.

    Section 12.    ADJUSTMENT OF NUMBER OF WARRANT SHARES PURCHASABLE.

    (a)  The number of shares of Common Stock purchasable upon the exercise of
each Warrant is subject to adjustment from time to time upon the occurrence of
any of the events enumerated in this Section 12 at any time or from time to time
after the date hereof and prior to the Expiration Date.

    (b)  If the Issuer shall (i) declare a dividend on the Common Stock in
shares of its capital stock (whether shares of Common Stock or of capital stock
of any other class), (ii) split or subdivide the outstanding Common Stock or
(iii) combine the outstanding Common Stock into a smaller number of shares, each
Warrant outstanding at the time of the record date for such dividend or of the
effective date of such split, subdivision or combination shall thereafter
entitle the holder of such Warrant to receive the aggregate number and kind of
shares which, if such Warrant had been exercised immediately prior to such time,
such holder would have owned or have become entitled to receive by virtue of
such dividend, subdivision or combination.  Such adjustment shall be made
successively whenever any event listed above shall occur and, if a dividend
which is declared is not paid, each Warrant outstanding shall again entitle the
holder thereof to receive the number of shares of Common Stock as would have
been the case had such dividend not been declared.  If at any time, as a result
of an adjustment made pursuant to this subsection 12(b), the holder of any
Warrant thereafter exercised shall become entitled to receive any shares of
capital stock of the Issuer 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 Warrant Shares
contained in this Section 12, and the provisions of this Warrant Agreement with
respect to the Warrant Shares shall apply on like terms to such other shares.

    (c)  In case the Issuer shall make a distribution to all holders of Common
Stock (including any such distribution made in connection with a consolidation
or merger in which the issuer is the continuing corporation) of evidences of its
indebtedness, cash or other assets, each Warrant outstanding on the date of such
distribution shall thereafter entitle the holder of such Warrant to receive a
number of shares of Common Stock equal to the product of (i) the number of
shares of


                                      -9-


<PAGE>

Common Stock to which the holder of such Warrant was entitled immediately prior 
to such date of distribution and (ii) a fraction of which the numerator shall be
the then Current Market Price Per Share of Common Stock on such date and of 
which the denominator shall be the then Current Market Price Per Share of Common
Stock on such date less the fair market value, as reasonably determined by the 
Board of Directors of the Issuer and reasonably acceptable to the holders of a 
majority of the Warrants of the portion of the assets or evidences of 
indebtedness, or the portion of the cash, so to be distributed applicable to one
share of then-outstanding Common Stock.  Such adjustment shall be made 
successively whenever a date for such distribution is fixed (which date of 
distribution shall be the record date for such distribution if a record date 
therefor is fixed) and, if such distribution is not so made, each Warrant 
outstanding shall again entitle the holder thereof to receive the number of
shares of Common Stock as would have been the case had such date of distribtion
not been fixed.

    (d)  In the event of any capital reorganization of the Issuer, or of any
reclassification of the Common Stock (other than a subdivision or combination of
outstanding shares of Common Stock), or in case of the consolidation of the
Issuer with or the merger of the Issuer with or into any other corporation or of
the sale of the properties and assets of the Issuer as, or substantially as, an
entirety to any other corporation, each Warrant shall after such capital
reorganization, reclassification of Common Stock, consolidation, merger or sale
be exercisable upon the terms and conditions specified in this Warrant
Agreement, for the number of shares of stock or other securities or assets to
which a holder of the number of Warrant Shares purchasable (at the time of such
capital reorganization, reclassification of Common Stock, consolidation, merger
or sale) upon exercise of such Warrant would have been entitled upon such
capital reorganization, reclassification of Common Stock, consolidation, merger
or sale; and in any such case, if necessary, the provisions set forth in this
Section 12 with respect to the rights thereafter of the holders of the Warrants
shall be appropriately adjusted so as to be applicable, as nearly as may
reasonably be, to any shares of stock or other securities or assets thereafter
deliverable on the exercise of the Warrants.

    (e)  If any event occurs, as to which, in the good faith opinion of the
Board of Directors of the Issuer, the other provisions of this Section 12 are
not strictly applicable or (if strictly applicable) would not fairly protect the
purchase rights of the Warrants in accordance with the essential intent and
principles of such provisions, then the Board of Directors shall make an
adjustment in the application of such provisions, in accordance with such
essential intent and principles, so as to protect such purchase rights as
aforesaid, but in no event shall any such adjustment have the effect of
decreasing the number of shares of Common Stock purchasable upon the exercise of
each Warrant from that which would otherwise be determined pursuant to this
Section 12.

    (f)  No adjustment in the number of Warrant Shares purchasable shall be
required unless such adjustment would require an increase or decrease in the
aggregate number of Warrant Shares purchasable of at least 1%, PROVIDED that any
adjustments which by reason of this subsection 12(g) are not required to be made
shall be carried forward and taken into account in any subsequent adjustment. 
All calculations under this Section 12 shall be made to the nearest cent or to
the nearest hundredth of a share, as the case may be.


                                      -10-


<PAGE>

    (g)  Irrespective of any adjustments in the number or kind of shares
purchasable upon the exercise of the Warrant, Warrant Certificates theretofore
or thereafter issued may continue to express the same number and kind of shares
as are stated on the Warrant Certificates initially issuable pursuant to this
Warrant Agreement.

    (h)  If any question shall at any time arise with respect to the number of
Warrant Shares purchasable following any adjustment pursuant to this Section 12,
such question shall be determined by agreement between the holders of a majority
of the Warrants and the Issuer or, in the absence of such an agreement, by an
independent investment banking firm or an independent appraiser engaged by the
Issuer (in either case the cost of which engagement will be borne by the Issuer)
and reasonably acceptable to the Issuer and the holders of a majority of
Warrants and such determination shall be binding upon the Issuer and the holders
of the Warrants.

    (i)  Anything in this Section 12 to the contrary notwithstanding:

         (1)  the Issuer shall be entitled to make such increases in the number
    of Warrant Shares purchasable upon the exercise of each Warrant, in
    addition to those adjustments required by this Section 12, as it in its
    sole discretion shall determine to be advisable in order that any
    consolidation or subdivision of the Common Stock, or any issuance wholly
    for cash or any shares of Common Stock at less than the Current Market
    Price Per share, or any issuance wholly for cash or shares of Common Stock
    or securities which by their terms are convertible into or exchangeable for
    shares of Common Stock or any stock dividend, or any issuance of rights,
    options or warrants referred to hereinabove in this Section 12, hereinafter
    made by the Issuer to the holders of its Common Stock shall not be taxable
    to them; and

         (2)  no adjustment in the number of Warrant Shares purchasable shall
    be required in the event the Issuer pays a cash dividend to holders of
    Common Stock; PROVIDED that the Issuer also pays a cash dividend to all
    holders of Warrants which dividend shall be calculated as if the Warrants
    had been exercised.

    Section 13.  NOTICES TO WARRANT HOLDERS; NOTICES OF ISSUANCES AND DIVIDENDS.

    (a)  Upon any adjustment of the number of Warrant Shares purchasable upon
exercise of a Warrant pursuant to Section 12, the Issuer shall promptly but in
any event within 20 days thereafter, cause to be delivered (i) by hand, (ii) by
telecopy or facsimile transmission (receipt confirmed), or (iii) by
international overnight or express courier, to each of the registered holders of
the Warrants at its address appearing on the Warrant Register, a certificate
signed by its chairman, president or chief financial officer setting forth the
number of Warrant Shares purchasable upon exercise of a Warrant as so adjusted
and describing in reasonable detail the facts accounting for such adjustment and
the method of calculation used.  Where appropriate, such certificate may be
given in advance and included as a part of the notice required to be mailed
under the other provisions of this Section 13.


                                      -11-


<PAGE>

    (b)  The Issuer shall deliver to each of the registered holders of the
Warrants at its address appearing on the Warrant Register, copies of all
information provided to holders of Common Stock concurrently with the delivery
thereof to such holders of Common Stock.

    Section 14.    RESTRICTIONS ON TRANSFER.

    (a)  Each Purchaser and its Affiliates who are issued Warrants pursuant to
this Agreement (i) represents that it is acquiring the Warrants for its own
account for investment and not with a view to any distribution or public
offering within the meaning of the Securities Act, except in any case pursuant
to the registration of such Warrants or Warrant Shares under the Securities Act
or pursuant to a valid exemption from such registration requirement, (ii)
acknowledges that the Warrants and the Warrant Shares issuable upon exercise
thereof have not been registered under the Securities Act and (iii) agrees that
it will not sell or otherwise transfer any of its Warrants or Warrant Shares
except upon the terms and conditions specified herein and that it will cause any
transferee thereof to agree to take and hold the same subject to the terms and
conditions specified herein, PROVIDED that the Warrant Holders may sell the
Warrants or the Warrant Shares purchased upon exercise of the Warrants in one or
more private transactions not requiring registration under the Securities Act.

    (b)  Except as provided in subsection 14(d) hereof each Warrant Certificate
and each certificate for the Warrant Shares issued to a Purchaser or an
Affiliate thereof or to a subsequent transferee thereof pursuant to subsection
14(c) shall include a legend in substantially the following form (with such
changes therein as may be appropriate to reflect whether such legend refers to
Warrants or Warrant Shares), PROVIDED that such legend shall not be required if
such transfer is being made in connection with a sale which is exempt from
registration pursuant to Rule 144 under the Securities Act or if the opinion of
counsel referred to in subsection 14(c) is to the further effect that neither
such legend nor the restrictions on transfer in this Section 14 are required in
order to ensure compliance with the Securities Act:

    "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR THE SECURITIES LAWS
OF ANY APPLICABLE STATE OR OTHER JURISDICTION, HAVE BEEN ACQUIRED FOR INVESTMENT
AND NOT WITH A VIEW TO DISTRIBUTION OR RESALE AND MAY NOT BE SOLD, MORTGAGED,
PLEDGED, HYPOTHECATED OR OTHERWISE TRANSFERRED IN THE ABSENCE OF (1) AN
EFFECTIVE REGISTRATION STATEMENT COVERING SUCH SECURITIES UNDER THE ACT AND ANY
SECURITIES LAWS OF ANY APPLICABLE STATE OR OTHER JURISDICTION, (2) AN EXEMPTION
FROM REGISTRATION PURSUANT TO RULE 144 UNDER THE ACT OR (3) A WRITTEN OPINION IN
FORM AND SUBSTANCE SATISFACTORY TO THE COMPANY TO THE EFFECT THAT REGISTRATION
IS NOT REQUIRED PURSUANT TO SOME OTHER APPLICABLE EXEMPTION FROM REGISTRATION
UNDER THE ACT OR UNDER OTHER APPLICABLE SECURITIES LAWS."

    (c)  Prior to any assignment, transfer or sale of any Warrant or any
Warrant Shares (other than a transfer between a Purchaser and/or its
Affiliates), the holder thereof shall give written notice


                                      -12-


<PAGE>

to the Issuer of such holder's intention to effect such assignment, transfer or 
sale, which notice shall set forth the date of such proposed assignment, 
transfer or sale and the identity of the proposed transferee.  Each holder 
wishing to effect such a transfer of any Warrant or Warrant Shares shall also 
furnish to the Issuer an agreement by the transferee thereof that it is taking 
and holding the same subject to the terms and conditions specified herein and, 
unless such transfer is being made pursuant to Rule 144 under the Securities 
Act, a written opinion of counsel  in form and substance reasonably satisfactory
to the Issuer to the effect that the proposed transfer may be effected without 
registration under the Securities Act.

    (d)  The restrictions set forth in this Section 14 shall terminate and
cease to be effective with respect to any Warrants or Warrant Shares which are
registered under the Securities Act or upon receipt by the Issuer of an opinion
of counsel, in form reasonably satisfactory to the Issuer, to the effect that
compliance with such restrictions is not necessary in order to comply with the
Securities Act with respect to the transfer of the Warrants and the Warrant
Shares; PROVIDED, HOWEVER, that after two (2) years from the date of issuance of
any Warrants, such restrictions will automatically terminate (without the
necessity of any opinion of counsel) as to such Warrants and as to any Warrant
Shares issued in respect of such Warrants upon exercise of the Conversion Right
set forth in subsection 6(b) above.  Whenever such restrictions shall so
terminate the holder of such Warrants and/or Warrant Shares shall be entitled to
receive from the Issuer, without expense (other than transfer taxes, if any),
Warrant Certificates or certificates for such Warrant Shares not bearing the
legend set forth in subsection 14(b) at which time the Issuer will rescind any
transfer restrictions relating thereto.

    (e)  With a view to making available to holders of the Warrants the
benefits of certain rules and regulations of the Securities and Exchange
Commission (including, without limitation, Rules 144 and 144A under the
Securities Act) which may permit the sale of Warrants and Warrant Shares to the
public or certain other institutions without registration, the Issuer agrees to
take any and all such actions as may be required of it to make available to such
holders such benefits, including without limitation, to:

         (i)  make and keep public information available, as those terms are
    understood and defined in Rule 144 under the Securities Act or any
    successor provision thereto from and after the date the Issuer first
    becomes subject to the provisions of Section 13 or 15(d) of the Exchange
    Act;

         (ii) file with the Commission in a timely manner all reports and other
    documents required of the Issuer under the Securities Act and the Exchange
    Act from and after the date the Issuer first becomes subject to the
    provisions of Section 13 or 15(d) of the Exchange Act; and

         (iii)     so long as a Purchaser or an Affiliate thereof owns any
    Warrants or Warrant Shares, furnish to such Purchaser forthwith upon
    request a written statement by the Issuer as to its compliance with the
    reporting requirements of Rule 144 or any successor provision thereto, and
    of the Securities Act and the Exchange Act, a copy of the most recent
    annual or


                                      -13-


<PAGE>

quarterly report of the Issuer filed with the Commission, in each case from and 
after the date the Issuer first becomes subject to the provisions of Section 
13 or 15(d) of the Exchange Act, and such other reports and documents of the 
Issuer and other information in the possession of or reasonably obtainable by 
the Issuer as such Purchaser and its Affiliates and subsequent holders of the 
Warrants may reasonably request in availing itself of any rule or regulation of 
the Commission allowing such Purchaser and its Affiliates and subsequent holders
of the Warrants to sell any such securities without registration.

    Section 15.         REDEMPTION.

    (a)  On not less than thirty (30) days prior written notice (a "REDEMPTION
NOTICE") given at any time commencing after the first anniversary of the date of
this Agreement and during the time the Warrants are outstanding, the Warrants
may be redeemed, in whole, but not in part, at the option of the Company, at a
redemption price of $.01 per Warrant (the "REDEMPTION PRICE"); PROVIDED that the
daily closing bid price per share of Common Stock (determined by reference to
the appropriate source as referenced in the definition of "Current Market Value
Per Shares" contained herein) for at least the twenty (20) consecutive Trading
Days ending on the fifth business day prior to the date of such Redemption
Notice shall exceed (i) during the period commencing on the first anniversary of
the date of this Agreement and ending on the date prior to the second
anniversary of the date of this Agreement, $16 per share, (ii) during the period
commencing on the second anniversary of the date of this Agreement and ending on
the date prior to the third anniversary of the date of this Agreement, $20 per
share, (iii) during the period commencing on the third anniversary of the date
of this Agreement and ending on the date prior to the fourth anniversary of the
date of this Agreement, $24 per share and (iv) during the period commencing on
the fourth anniversary of the date of this Agreement and ending on the
Expiration Date, $28 per share (each such amount being a "Target Price"), in
each case subject to adjustment as set forth in Section 15(f) below.

    (b)  In the event the conditions set forth in Section 15(a) are met, and
the Company shall desire to exercise its right to redeem the Warrants, it shall
deliver (i) by hand, (ii) by telecopy or facsimile transmission (receipt
confirmed), or (iii) by international overnight or express courier, a notice of
redemption to each of  the holders of the Warrants to be redeemed, not later
than the thirtieth day before the date fixed for redemption, at their last
address as shall appear on the Warrant Register.  Any Redemption Notice
delivered in the manner provided herein shall be conclusively presumed to have
been duly given whether or not the Warrant Holder receives such notice, absent
fraud.

    (c)  The Redemption Notice shall specify the (i) the Redemption Price, (ii)
the date fixed for redemption, (iii) the place where the Warrant Certificates
shall be delivered and the Redemption Price paid and (iv) that the right to
exercise the Warrant shall terminate at 5:00 P.M. (New York time) on the
business day immediately preceding the date fixed for redemption.  The date
fixed for the redemption of the Warrants shall be the "REDEMPTION DATE".  No
failure to mail such notice nor any defect therein or in the mailing thereof
shall affect the validity of the proceedings for such redemption except as to a
holder (a) to whom notice was not mailed or (b) whose notice was defective.  An
affidavit of the Secretary or an Assistant Secretary of the Company that a
Redemption


                                      -14-


<PAGE>

Notice has been mailed shall, in the absence of fraud, be prima facie evidence 
of the facts stated therein.

    (d)  Any right to exercise a Warrant shall terminate at 5:00 P.M. (New York
time) on the business day immediately preceding the Redemption Date.  On and
after the Redemption Date, holders of the Warrants called for redemption shall
have no further rights except to receive, upon surrender of the Warrant, the
Redemption Price.

    (e)  From and after the Redemption Date, the Company shall, at the place
specified in the Redemption Notice, upon presentation and surrender to the
Company by or on behalf of the holder thereof of one or more Warrants to be
redeemed, deliver or cause to be delivered to or upon the written order of such
holder a sum in cash equal to the Redemption Price of each such Warrant.  From
and after the Redemption Date and upon the deposit or setting aside by the
Company of a sum sufficient to redeem all the Warrants called for redemption,
such Warrants shall expire and become void and all rights hereunder and under
the Warrant Certificates, except the right to receive payment of the Redemption
Price, shall cease.

    (f)  If the shares of the Company's Common Stock are subdivided or combined
into a greater or smaller number of shares of Common Stock or if there is stock
dividend to holders of Common Stock, the applicable Target Price shall be
proportionally adjusted by the ratio which the total number of shares of Common
Stock outstanding immediately prior to such event bears to the total number of
shares of Common Stock to be outstanding immediately after such event.

    Section 16.    AMENDMENTS AND WAIVERS.  Any provision of this Warrant
Agreement may be amended, supplemented, waived, discharged or terminated by a
written instrument signed by the Issuer and the holders of not less than a
majority of the outstanding Warrants (or in the case of Section 14, the holders
of a majority of the aggregate outstanding Warrants and Non-Public Warrant
Shares, voting as a single group), PROVIDED that (i) this Agreement may not be
amended, supplemented or waived so as to increase the Exercise Price, reduce the
Redemption Price, reduce the number of Warrant Shares issuable upon exercise of
any Warrants, alter the period during which any Warrants may be exercised
(except to provide for a later Expiration Date) or redeemed, in each case
without the consent of the holders of all outstanding Warrants and (ii) this
Section 16 may not be amended or supplemented without the consent of the holders
of all outstanding Warrants and Non-Public Warrant Shares, voting as a single
group, and no waiver of the requirements of this Section 16 shall be binding
upon any such holder without its consent.

    Section 17.    SPECIFIC PERFORMANCE.  The parties agree that irreparable
damage will result in the event that the obligations of the Issuer under this
Warrant Agreement are not specifically enforced, and that any damages available
at law for a breach of any such obligations would be inadequate.  Therefore, the
holders of the Warrants and/or Non-Public Warrant Shares shall have the right to
specific performance by the Issuer of the provisions of this Warrant Agreement,
and appropriate injunctive relief may be applied for and granted in connection
therewith.  The Issuer hereby irrevocably waives, to the extent that it may do
so under applicable law, any defense based on the adequacy of a remedy at law
which may be asserted as a bar to the remedy of specific


                                      -15-


<PAGE>

performance in any action brought against the Issuer for specific performance of
this Warrant Agreement by the holders of the Warrants and/or Non-Public Warrant 
Shares.  Such remedies and all other remedies provided for in this Warrant 
Agreement shall, however, be cumulative and not exclusive and shall be in 
addition to any other remedies which may be available under this Warrant 
Agreement.

    Section 18.    NOTICES.

    (a)  Any notice or demand to be given or made by the Warrant Holders or the
holders of Warrant Shares to or on the Issuer pursuant to this Warrant Agreement
shall be sufficiently given or made if (i) delivered by hand, (ii) sent by
telecopy or facsimile transmission (receipt confirmed), or (iii) delivered by
international overnight or express courier, addressed to the Issuer at the
Warrant Office.

    (b)  Any notice to be given by the Issuer to the Warrant Holders or the
holders of Warrant Shares shall be sufficiently given or made if (i) delivered
by hand, (ii) sent by telecopy or facsimile transmission (receipt confirmed), or
(iii) delivered by international overnight or express courier, addressed to such
holder as such holder's name and address shall appear on the Warrant Register or
the Common Stock registry of the Issuer, as the case may be.

    Section 19.    BINDING EFFECT.  This Warrant Agreement shall be binding
upon and inure to the sole and exclusive benefit of the Issuer, its successors
and assigns, the Purchasers, Affiliates of the Purchasers and the registered
holders from time to time of the Warrants and the Warrant Shares.

    Section 20.    CONTINUED VALIDITY.  A holder of Warrant Shares shall
continue to be entitled with respect to such Warrant Shares to all rights and
subject to all obligations to which it would have been entitled or subject as a
Warrant Holder under Sections 14 through 23 of this Warrant Agreement.  The
Issuer will, at the time of each exercise of any Warrant, in whole or in part,
upon the request of the holder of the Warrant Shares issued upon such exercise
thereof, acknowledge in writing, in form reasonably satisfactory to such holder,
its continuing obligation to afford to such holder all such rights, PROVIDED,
HOWEVER, that if such holder shall fail to make any such request, such failure
shall not affect the continuing obligation of the Issuer to afford to such
holder all such rights.

    Section 21.    COUNTERPARTS.  This Warrant Agreement may be executed in one
or more separate counterparts and all of said counterparts taken together shall
be deemed to constitute one and the same instrument.

    Section 22.    DELAWARE LAW.  THIS WARRANT AGREEMENT AND EACH WARRANT
CERTIFICATE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF
THE STATE OF DELAWARE.

    Section 23.    BENEFITS OF THIS WARRANT AGREEMENT.  Nothing in this Warrant
Agreement shall be construed to give to any Person other than the Issuer and the
registered holders of the Warrants and the Warrant Shares any legal or equitable
right, remedy or claim under this Warrant Agreement.


                                      -16-


<PAGE>

    Section 24.    VOTING AND CONSENTS TO BE ON A FULLY CONVERTED BASIS. 
Wherever this Warrant Agreement calls for the written consent or vote of any
combinations of the holders of the Warrants and the Warrant Shares, voting as a
single group, the Warrants shall be counted as if they had been exercised for
Common Stock.

    Section 25.    ENTIRE AGREEMENT.  This Warrant Agreement constitutes the
entire agreement between the parties hereto with respect to the subject matter
hereof and supersedes all prior negotiations, understandings and agreements
between such parties in respect of such subject matter.

    [Remainder of page intentionally left blank]















                                      -17-


<PAGE>

    IN WITNESS WHEREOF the parties hereto have caused this Warrant Agreement to
be duly executed and delivered by their proper and duly authorized officers, as
of the date and year first above written.
      

                                       SUNPHARM CORPORATION

                                       By:_____________________________________

                                       Name:___________________________________

                                       Title:__________________________________





                    Counterpart Signature Pages Begin on Next Page







                                      -18-


<PAGE>

                      COUNTERPART SIGNATURE PAGE FOR PURCHASERS

    The undersigned hereby agrees to become a party to that certain Unit
Purchase Agreement dated as of March 28, 1997 (the "Agreement") among SunPharm
Corporation (the "Company") and others and that certain Warrant Agreement dated
as of March 28, 1997 (the "Warrant Agreement") among the Company and others. 
From and after the undersigned's execution and delivery and the Company's
acceptance of this Counterpart Signature Page, the undersigned shall be a party
to the Agreement and the Warrant Agreement, and the Units (including the Shares
and the Warrants) purchased by the undersigned shall be deemed to be "Units" for
all purposes of the Agreement and the Warrants purchased by the undersigned
shall be deemed to be "Warrants" for all purposes of the Warrant Agreement .


                                       Printed Name of Purchaser

                                       ________________________________________
                                       Signature of Purchaser

                                       ________________________________________

                                       Investment Amount:______________________

                                       Number of Units:________________________

                                       By:_____________________________________

                                       Title:__________________________________

                                       Address:________________________________

                                       Date:___________________________________

Agreed and accepted to as to_________  Units at $3.50 per Unit:

SUNPHARM CORPORATION

By:__________________________________

Title:_______________________________

Date:________________________________


                                      -19-


<PAGE>

                                      Exhibit A

                                  WARRANT AGREEMENT



                                 WARRANT CERTIFICATE

    THE WARRANTS AND SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE
SECURITIES LAW AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH
REGISTRATION OR AN EXEMPTION THEREFROM UNDER SUCH ACT OR LAW.  THE WARRANTS
REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN EXCHANGE RIGHTS MORE
FULLY SET FORTH IN THE WARRANT AGREEMENT REFERRED TO BELOW.

                            EXERCISABLE ONLY ON OR BEFORE
                                    March 28, 2002

                                 Warrant Certificate
    This Warrant Certificate certifies that ____________________________, or
registered assigns, is the registered holder of ________________ Warrants (the
"Warrants") to purchase Common Stock of SUNPHARM CORPORATION, a Delaware
corporation (the "Issuer").  Each Warrant entitles the holder, but only subject
to the conditions set forth herein and in the Warrant Agreement referred to
below, to purchase from the Issuer before 5:00 P.M., New York time, on March 28,
2002 (the "Expiration Date"), one (1) fully paid and nonassessable share of the
Common Stock of the Issuer (the "Warrant Shares") at the exercise price set
forth in the Warrant Agreement (the "Exercise Price"), payable in lawful money
of the United States of America, upon surrender of this Warrant Certificate,
execution of the annexed Form of Election to Purchase and payment of the
Exercise Price at the office of the Issuer at 4561 Salisbury Road, Jacksonville,
FL  33256 or such other address as the Issuer may specify in writing to the
registered holder of the Warrants evidenced hereby (the "Warrant Office").  In
lieu of exercising Warrants pursuant to the immediately preceding sentence, the
Warrant holder shall have the right to require the Issuer to convert the
Warrants, in whole or in part and at any time or times, into Warrant Shares, by
surrendering to the Issuer the Warrant Certificate evidencing the Warrants to be
converted, accompanied by the annexed Form of Notice of Conversion which has
been duly completed and signed.  The Exercise Price and number of Warrant Shares
purchasable upon exercise of the Warrants are subject to adjustment prior to the
Expiration Date as set forth in the Warrant Agreement. 


                                      -20-


<PAGE>

    No Warrant may be exercised after 5:00 P.M., New York time, on the
Expiration Date and (except as otherwise provided in the Warrant Agreement) all
rights of the registered holders of the Warrants shall cease after 5:00 P.M.,
New York time, on the Expiration Date.

    The Issuer may redeem the Warrants, on the terms and subject to the
conditions set forth in the Warrant Agreement.

    The Issuer may deem and treat the registered holders of the Warrants
evidenced hereby as the absolute owners thereof (notwithstanding any notation of
ownership or other writing hereon made by anyone), for the purpose of any
exercise hereof and of any distribution to the holders hereof and for all other
purposes, and the Issuer shall not be affected by any notice to the contrary.

    Warrant Certificates, when surrendered at the office of the Issuer at the
above-mentioned address by the registered holder hereof in person or by a legal
representative duly authorized in writing, may be exchanged, in the manner and
subject to the limitations provided in the Warrant Agreement, but without
payment of any service charge, for another Warrant Certificate or Warrant
Certificates of like tenor evidencing in the aggregate a like number of
Warrants.

    Upon due presentment for registration of transfer of this Warrant
Certificate at the office of the Issuer at the above-mentioned address, a new
Warrant Certificate or Warrant Certificates of like tenor and evidencing in the
aggregate a like number of Warrants shall be issued in exchange for this Warrant
Certificate to the transferee(s) and, if less than all the Warrants evidenced
hereby are to be transferred, to the registered holder hereof, subject to the
limitations provided in the Warrant Agreement, without charge except for any tax
or other governmental charge imposed in connection therewith.

    This Warrant Certificate is one of the Warrant Certificates referred to in
the Warrant Agreement, dated as of March 28, 1997, between the Issuer and the
Purchasers signatory thereto.  Said Warrant Agreement is hereby incorporated by
reference in and made a part of this instrument and is hereby referred to for a
description of the rights, limitation of rights, obligations, duties and
immunities thereunder of the Issuer and the holders.

    IN WITNESS WHEREOF the Issuer has caused this Warrant Certificate to be
signed by its duly authorized officer. 

                                  SUNPHARM CORPORATION
                                  By:_________________________________________

                                  Name:_______________________________________

                                  Title:______________________________________


                                      -21-


<PAGE>

                                    ANNEX to Form
                                      of Warrant
                                     CERTIFICATE

                             FORM OF ELECTION TO PURCHASE
                      (To be executed upon exercise of Warrant)


    The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant Certificate, to purchase ______ Warrant Shares* and
herewith tenders payment for such Warrant Shares to the order of the Issuer in
the amount of $__________ in accordance with the terms hereof.  The undersigned
requests that a certificate for such Warrant Shares be registered in the name of
___________________________________________________ whose address is
_____________________________________________________ and that such certificate
be delivered to _________________ whose address is
____________________________________.  If said number of Warrant Shares is less
than all of the Warrant Shares purchasable hereunder, the undersigned requests
that a new Warrant Certificate representing the remaining balance of the Warrant
Shares be registered in the name of ____________________________ whose address
is __________________________________________________ and that such Warrant
Certificate be delivered to __________________________________ whose address is
___________________________________________________.

Signature:
________________________________
(Signature must conform in all respects to name of holder as specified on the
face of the Warrant Certificate.)

Date: __________

*  Consisting of:
   _____ shares of Common Stock


                                      -22-


<PAGE>

                                    ANNEX to Form
                                      of Warrant
                                     CERTIFICATE

                             FORM OF NOTICE OF CONVERSION
                     (To be executed upon conversion of Warrant)

    The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant Certificate, to convert Warrants represented hereby
into ____ Warrant Shares* in accordance with the terms hereof.  The undersigned
requests that a certificate for such Warrant Shares be registered in the name of
________________________________________________ whose address is
______________________________________________________________ and that such
certificate be delivered to ____________________________ whose address is
__________________________________________________.  If said number of Warrant
Shares is less than all of the Warrant Shares obtainable hereunder, the
undersigned requests that a new Warrant Certificate representing the remaining
balance of the Warrant Shares be registered in the name of
____________________________________ whose address is ______________
__________________________________________ and that such Warrant Certificate be
delivered to ____________________________________ whose address is
__________________________________________________.
Signature:

________________________________
(Signature must conform in all respects to name of holder as specified on the
face of the Warrant Certificate.)

Date: __________
*  Consisting of:
    ____ shares of Common Stock




                                      -23-


<PAGE>

                                     EXHIBIT B to
                                  WARRANT AGREEMENT


                                   WARRANT REGISTER


Warrant       Original Number of        Number of      Names and
Certificate   Warrants and Warrant      Warrants       Addresses of
Number        Shares                    Expired        Warrant Holders
------        ------                    -------        ---------------















                                      -24-