<Page>





                           LOAN AND SECURITY AGREEMENT

     THIS LOAN AND SECURITY AGREEMENT is made as of this 8th day of April, 2002,
by and among Photogen Technologies, Inc., a Nevada corporation, and Photogen,
Inc., a Tennessee corporation (each, a "Borrower" and collectively, the
"Borrowers") jointly and severally, and Tannebaum, LLC, a Delaware limited
liability company ("Lender").

     For and in consideration of the mutual promises herein and for other good
and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the parties hereto agree as follows:

     1. DEFINED TERMS. Whenever used herein:

          (a) "ADVANCE" shall mean any disbursement of funds pursuant to the
Note.

          (b) "AGREEMENT" shall mean this Loan and Security Agreement.

          (c) "COLLATERAL" shall mean any and all property, assets, rights and
interests of the Borrowers, of any kind or description, tangible or intangible,
whether now existing or hereafter arising or acquired, wherever located, and all
other rights in connection therewith and the products and proceeds therefrom,
including the proceeds of insurance thereon, including, but not limited to, the
following (all words, whether or not capitalized, in this definition of
Collateral for which there is a definition in the UCC shall have the meaning
given to them in the UCC): all property of the Borrowers, whether now existing
or hereafter arising or acquired, and wherever now or hereafter located,
together with all additions and accessions thereto, substitutions for, and
replacements, products and proceeds therefrom, and all of the Borrowers' books
and records and recorded data relating thereto (regardless of the medium of
recording or storage), together with all of the Borrowers' right, title and
interest in and to all computer software required to utilize, create, maintain
and process any such records or data on electronic media, including the
following:

          i. All accounts and all goods whose sale, lease or other disposition
by the Borrowers has given rise to accounts and have been returned to, or
repossessed or stopped in transit by the Borrowers, or rejected or refused by an
account debtor;

          ii. All inventory, including, without limitation, raw materials,
packaging, work-in-process and finished goods ("Inventory");

          iii. All goods (other than Inventory), including, without limitation,
embedded software, equipment, furniture and fixtures;

          iv. All software and computer programs;

          v. All securities, investment property, cash, cash equivalents,
financial assets and deposit accounts;


<Page>


          vi. All chattel paper, electronic chattel paper, instruments,
documents, letter of credit rights, all proceeds of letters of credit, health
care insurance receivables, supporting obligations, notes secured by real
estate, contract rights and general intangibles, including payment intangibles,
patents, know how, copyrights, service marks, trade names, licenses, trade
secrets, goodwill and beneficial interests;

          vii. All insurance policies insuring the foregoing property or any
part thereof and all proceeds of such insurance policies; and

          viii. all other property of the Borrowers, real and/or personal, in
which the Borrowers heretofore, now and/or from time to time hereafter has an
interest, it being the intent of the parties hereto that the grant of a security
interest hereby be broadly interpreted to include all property of the Borrowers
whether real, personal, now existing or hereafter acquired or arising.

          (d) "EVENTS OF DEFAULT" shall mean the occurrence of any one or more
of the following events:

          i. Failure to make prompt payment when due, of any payment due on any
of the Indebtedness to Lender, or failure to promptly perform any covenant,
promise or agreement contained in this Agreement or in the Note, or in any of
the Other Agreements;

          ii. If any representation, warranty or other information made or
furnished to Lender shall be false or incorrect;

          iii. If any Borrower shall make a general assignment for the benefit
of creditors, or shall state in writing or by public announcement its inability
to pay its debts as they become due, or shall file a petition in bankruptcy, or
shall be adjudicated a bankrupt, or insolvent, of shall file a petition seeking
any reorganization, arrangement, composition, readjustment, liquidation,
dissolution or similar relief under any present or future statute, law or
regulation, or shall file an answer admitting or not contesting the material
allegations of a petition against it in any such proceeding, or shall seek or
consent to or acquiesce in the appointment of any trustee, receiver or
liquidator of such Borrower, or any material portion of its assets;

          iv. If any proceeding is commenced by or against any Borrower seeking
any reorganization, arrangement, composition, readjustment, liquidation,
dissolution or similar relief under any present or future statute, law or
regulations, or if, any trustee, receiver or liquidator of any Borrower or any
material portions of its respective assets are appointed;

          v. The filing or assertion of any suit or claim against any Borrower,
or the occurrence of any other event or circumstance, which in the reasonable
exercise of Lender's judgment may have a Material Adverse Effect, except any
suit or claim disclosed in the 2001 Form 10-K (defined below);


                                      -2-
<Page>


          vi. Dissolution, merger or consolidation of any Borrower, or sale,
transfer, lease or other disposition of substantially all of the assets of any
Borrower other than in the ordinary course of business or any sale of assets to
Lender;

          vii. If in the reasonable exercise of its judgment, Lender deems
itself insecure;

          viii. The making of any levy, seizure, or attachment upon the
Collateral or if any Lien is granted or imposed upon the Collateral other than
the Lien created under this Agreement;

          ix. Any claim or action is brought against Lender arising out of the
transactions in this Agreement;

          x. Failure to fully comply with the requirements of any governmental
agency or authority within thirty (30) days after notice of such requirements,
if, in the reasonable exercise of Lender's judgment such failure to comply will
have a Material Adverse Effect; or

          xi. The direct or indirect use of Proceeds for any purpose other than
as specified herein.

          (e) "INDEBTEDNESS" shall mean all obligations of the Borrowers to any
person or entity, howsoever created, arising or evidenced, whether direct or
indirect, absolute or contingent, or now or hereafter existing, or due or to
become due, and all principal, interest, taxes, fees, charges, expenses and
reasonable attorneys' fees, chargeable to the Borrowers pursuant to any
agreement evidencing such Indebtedness.

          (f) "LIEN" shall mean any mortgage, pledge, lien, hypothecation,
claim, demand, charge, assessment, security interest or encumbrance.

          (g) "LOAN" shall mean the obligations of the Borrowers to Lender as
evidenced by the Note.

          (h) "MATERIAL ADVERSE EFFECT" shall mean a material adverse effect on
(i) the business, assets, liabilities (contingent or otherwise), operations,
conditions (financial or otherwise), or prospects of the Borrowers, (ii) the
rights of Lender under this Agreement or the Note (including the enforceability
of Lender's Lien or other rights granted herein), or (iii) the ability of the
Borrowers to pay the Loan or perform their other obligations in this Agreement
and the Note.

          (i) "MATURITY DATE" shall mean 5:00 p.m., Chicago time, on April 1,
2007 or such earlier date on which an Event of Default occurs.

          (j) "NOTE" shall mean that Revolving Note of even date herewith
executed by the Borrowers and payable to the order of Lender, in the principal
sum of TWO MILLION FIVE HUNDRED THOUSAND DOLLARS AND NO CENTS ($2,500,000.00)
and any other promissory note or obligation of the Borrowers evidencing any
Advance or Loan made by Lender to the Borrowers, together with any request for
an Advance pursuant to the Note.


                                      -3-
<Page>


          (k) "OTHER AGREEMENTS" shall mean all agreements, instruments and
documents, including, without limitation, bond agreements, loan agreements,
security agreements, indemnity agreements, guaranties, mortgages, leasehold
mortgages, deeds of trust, collateral assignments, notes, applications and
agreements for letters of credit, letters of credit, advices of credit, the
Lender's acceptances, pledges, powers of attorney, consents, assignments,
contracts, notices, leases, financing statements and all other written matters
heretofore, now and/or from time to time hereafter executed by and/or on behalf
of the Borrowers and delivered to the Lender, or issued by the Lender upon the
application and/or other request of, and on behalf of, the Borrowers.

          (l) "PROCEEDS" shall mean the aggregate proceeds received by any
Borrower from Lender from Advances.

          (m) "UCC" shall mean the Uniform Commercial Code as adopted by the
State of Illinois, and as amended from time to time.

     2. CLOSING. The closing of the transactions contemplated hereby (the
"CLOSING") shall occur on or before April 9, 2002 (the "CLOSING DATE") by mail,
Federal Express or fax. An executed document whose signature page is transmitted
by fax shall be deemed fully executed and the document duly delivered by such
party upon completion of the fax transmission, and such party shall provide
original signature pages within two business days thereafter. At the Closing,
the parties hereto shall execute and deliver to each other, as applicable: (i)
the Note payable to the order of the Lender or its designee; and (ii) any other
documents or instruments reasonably requested by a party hereto.

     3. LOAN.

          (a) AMOUNT. The principal amount of the Loan shall not exceed TWO
MILLION FIVE HUNDRED THOUSAND DOLLARS AND NO CENTS ($2,500,000.00) in aggregate
principal amount at any one time outstanding and shall be available to the
Borrowers until the Termination Date. Each Advance shall be repaid as provided
herein.

          (b) ADVANCE PROCEDURE. Advances to the Borrowers under the Note shall
be requested and made pursuant to the Note. Each Advance shall be in a minimum
amount of $100,000.00. Lender will not be required to fund any Advance if any
Borrower is in default under any of the terms and conditions of this Agreement
or the Note, or at any time after the Termination Date. Each request for Advance
shall be subject to Lender's approval which Lender may or may not grant in its
sole and absolute discretion. As a condition of making any Advance if so
requested by Lender, the Borrowers shall acknowledge in writing that the
existing principal balance and accrued interest as of the time of such Advance
is true and correct.

          (c) REPAYMENT OF NOTE. All principal and accrued interest shall be
repaid to the Lender in accordance with the Note. Amounts repaid may be
reborrowed until the Maturity Date; provided, that the maximum principal amount
outstanding under the Loan at any time shall not exceed $2,500,000.00.



                                      -4-
<Page>

          (d) JOINT AND SEVERAL OBLIGATION. All Indebtedness, payments,
obligations and liabilities pursuant to and under this Agreement and Note shall
be the joint and several liability of each Borrower.

     4. USE OF PROCEEDS. Borrowers shall use all Proceeds from the transactions
under this Agreement for business and commercial purposes, and specifically,
only for working capital purposes and for no other purposes.

     5. TRANSACTION FEES. In addition to all other amounts due and payable by
Borrowers hereunder, each Borrower promises to pay all filing or recording fees,
document taxes, transfer taxes and any other similar amount arising in
connection with the issuance of the Note, the perfection of the Purchaser's
security interest or otherwise.

     6. GRANT OF SECURITY INTEREST. To secure the payment and performance of all
Indebtedness Borrowers owe Lender, each Borrower hereby pledges, assigns and
grants to Lender a continuing security interest in any and all of the
Collateral.

     7. REPRESENTATIONS AND WARRANTIES OF BORROWERS. Except as disclosed in
writing to Lender (the receipt of which must be acknowledged in writing by
Lender), each Borrower warrants and represents to and covenants with Lender
that:

          (a) The Borrowers are duly organized, and validly existing under the
laws of the state of Nevada and Tennessee, respectively, and have all requisite
corporate power and authority to own and lease their properties, to carry on
their business as presently conducted and as proposed to be conducted and to
consummate the transactions contemplated hereby. The Borrowers have full power
and authority to execute and deliver this Agreement and the Note and to perform
their obligations hereunder and thereunder. The execution, delivery and
performance by the Borrowers of this Agreement and the Note, including the
issuance of the Note, have been duly authorized by all requisite action by the
Borrowers and, when executed and delivered by the Borrowers, this Agreement and
the Note will be the valid and binding obligations of the Borrowers, enforceable
against the Borrowers in accordance with their respective terms.

          (b) The consolidated audited balance sheets of Photogen Technologies,
Inc. at December 31, 2001, together with the related statements of operations,
stockholders' equity (deficit) and cash flows for the year ended December 31,
2001, together with the reports and opinions thereon of BDO Seidman, LLP,
contained in the 2001 Form 10-K, and the comparable unaudited financial
statements for the quarter ended March 31, 2002, comply (or will comply when
filed with the Securities and Exchange Commission) as to form in all material
respects with applicable accounting requirements and the published rules and
regulations of the SEC with respect thereto, and fairly present, in all material
respects, the financial position of the Borrowers and the results of its
operations and their cash flows at such dates and for the periods then ended and
were prepared in conformity in all material respects with generally accepted
accounting principles applied on a consistent basis.

          (c) The Borrowers have and at all times hereafter shall have good,
indefeasible and merchantable title to and ownership of the Collateral, free and
clear of all Liens, and the Collateral shall be located at Borrowers' facility
in Knoxville, Tennessee or in New


                                      -5-
<Page>

Hope, Pennsylvania. The Collateral is in good condition and is fit and usable
for the purposes for which the Borrowers use such items.

          (d) Each Borrower uses no trade names or assumed names in the conduct
of its business, and has not changed its name or been the surviving entity in a
merger or acquired any business in the last five (5) years.

          (e) Each Borrower is and will be the lawful owner of its portion of
the Collateral, free of any and all Liens whatsoever, other than the Lien
hereunder, with full power to subject the Collateral to the security interest
hereunder.

     8. AGREEMENTS OF BORROWERS.

          (a) Each Borrower hereby covenants and agrees that such Borrower:

          i. Shall, upon request of Lender, execute such financing statements
and other documents and do such other acts and things, all as Lender may from
time to time request to establish and maintain a perfected Lien in the
Collateral to secure the payment of the Indebtedness and to consummate the
transactions contemplated in or by this Agreement or the Note;

          ii. Shall permit Lender and its agents to inspect the Collateral, and
to inspect, audit and make copies of and extracts from all records and all other
papers in the possession of any Borrower and will, upon request of Lender,
deliver to Lender all of such records and papers which pertain to the
Collateral;

          iii. Shall not sell, lease, assign or transfer any of the Collateral
except in the ordinary course of its business consistent with past practices;

          iv. Shall keep the Collateral free of any Liens except the Lien
created hereunder, existing Liens of record and rights in favor of affiliates of
Elan Corporation, plc;

          v. Shall notify Lender in writing prior to any change in location of
its principal place of business or any change in location of the Collateral;

          vi. Shall indemnify and hold Lender harmless from any and all claims,
demands, losses, liabilities, actions, lawsuits and other proceedings,
judgments, awards, decrees, costs and expenses (including reasonable attorney's
fees), arising directly or indirectly, in whole or in part, out of the acts and
omissions whether negligent, willful or otherwise, of any Borrower, or any of
its respective officers, directors, agents, subagents, or employees, in
connection with the transactions contemplated herein or as a result of (A)
ownership of the Collateral or any interest therein or receipt of any sums
therefrom, (B) any failure on the part of any Borrower to perform or comply with
any of the terms of this Agreement or the Note, or (C) any claim asserted by any
party arising in connection with the Collateral; and

          (b) Each Advance made by Lender to a Borrower pursuant to this
Agreement or the Note shall constitute an automatic warranty and representation
by the Borrowers to Lender


                                      -6-
<Page>

that there does not then exist an "Event of Default" or any event or condition
which with notice, lapse of time, and/or the making of such loan would
constitute an Event of Default.

          (c) Lender, in its sole and absolute discretion, without notice
thereof to Borrowers, may disburse any or all Advances made to any Borrower
pursuant to this Agreement and/or the Loan Documents to pay any costs, expenses
or other amounts required to be paid by the Borrowers hereunder and not so paid,
and/or to pay any person as Lender deems necessary to insure that the Lien
granted to Lender in the Collateral shall at all times have the priority
represented and covenanted by this Agreement and the Loan Documents. All monies
so disbursed by Lender shall be a part of the Indebtedness, payable by Borrowers
to Lender on demand.

          (d) All of the representations and warranties contained herein, and
all representations and warranties contained in the other Loan Documents and any
other document or instrument delivered to Lender in connection herewith will be
and remain true and correct during the term of this Agreement.

     9. REMEDIES.

          (a) If any Event of Default shall occur, then or at any time
thereafter at the option of Lender, Lender may declare all of Borrowers'
Indebtedness owed to Lender to be immediately due and payable without notice,
protest, presentment or demand, all of which are expressly waived by Borrowers.
Lender shall have in addition to any other rights and remedies contained in this
Agreement and the Note, and any Other Agreements, heretofore, now, or at any
time hereafter executed by Borrowers and delivered to Lender, all of the rights
and remedies of a secured party under the UCC, all of which rights and remedies
shall be cumulative, and nonexclusive, to the fullest extent permitted by law.

          (b) Lender shall also have the right to avail itself to the following
rights and remedies:

          i. Demand repayment of the Note whereupon the Indebtedness shall
become immediately due and payable in full;

          ii. Terminate Lender's obligations under this Agreement to extend
credit of any kind or to make any Advances, whereupon the commitment and
obligations of Lender to extend credit, or to make Advances hereunder shall be
terminated;

          iii. Notify or require Borrowers to notify any and all persons or
entities against which any Borrower has a claim or which are obligors on
accounts or any other Indebtedness they may owe to any Borrower that Lender has
a security interest therein and that all payments should be made directly to
Lender;

          iv. Endorse the name of any Borrower upon any instruments of payments
that may come into the possession of Lender in full or in part payment of any
amount owing to Lender;


                                      -7-
<Page>


          v. Sell, assign, sue for, collect, or compromise payment of all or any
part of the Collateral in the name of any Borrower or in its own name, or make
any other disposition of the Collateral, or any part thereof, which disposition
may be cash, credit, or any combination thereof;

          vi. Purchase all or any part of the Collateral at public, or private
sale, and in lieu of actual payment of such purchase price, may set off the
amount of such price against the Indebtedness;

          vii. Enter and/or remain upon the premises of any Borrower without any
obligation to pay rent to such Borrower or others, or any other place or places
where any of the Collateral is located and kept and: (A) remove Collateral
therefrom to the premises of Lender or any agent of Lender, for such time as
Lender may desire, in order to maintain, sell, collect, and/or liquidate the
Collateral; or (B) use such premises, together with materials, supplies, books,
and records of the Borrowers, to maintain possession and/or the condition of the
Collateral, and to prepare the Collateral for selling, liquidating, or
collecting;

          viii. Require the Borrowers to assemble the Collateral and make it
available to Lender at a place to be designated by Lender; and

          ix. Apply the net proceeds realized by Lender upon a sale or other
disposition of the Collateral, or any part thereof, after deduction of the
expenses of retaking, holding, preparing for sale, selling, or the like, and
reasonable attorney's fees and other expenses incurred by Lender, toward
satisfaction of the Indebtedness hereunder. Lender shall account to Borrowers
for any surplus realized upon such sale or other disposition and Borrowers shall
remain liable for any deficiency.

          (c) Any notice required to be given by Lender of a sale or other
disposition of the Collateral or any other intended action by Lender, deposited
in the United States mail, postage prepaid, and duly addressed to Borrowers at
the address specified at the end of this Agreement not less than five (5) days
prior to such proposed action, shall constitute commercially reasonable and fair
notice to Borrowers thereof.

          (d) Upon the occurrence of an Event of Default, the Borrowers,
immediately upon demand by the Lender, shall assemble the Collateral and make it
available to the Lender at a place or places to be designated by the Lender
which are reasonably convenient to the Lender. The Borrowers recognize that in
the event the Borrowers fail to perform, observe or discharge any of the
Borrowers' Obligations, no remedy of law will provide adequate relief to the
Lender, and agrees that the Lender shall be entitled to temporary and permanent
injunctive relief in any such case without the necessity of proving actual
damages.

          (e) Upon the occurrence of an Event of Default, Borrowers agree that
Lender may, if Lender deems it reasonable, postpone or adjourn any such sale of
the Collateral from time to time by an announcement at the time and place of
sale or by announcement at the time and place of such postponed or adjourned
sale, without being required to give a new notice of sale. Borrowers agree that
Lender has no obligation to preserve rights against prior parties to the
Collateral. Further, to the extent permitted by law, Borrowers waive and release
any cause of


                                      -8-
<Page>


action and claim against Lender as a result of Lender's possession, collection
or sale of the Collateral, any liability for failure of Lender to comply with
any requirement relating to notice of sale, holding or reporting of sale of the
Collateral, and any right of redemption from such sale.

     10. ELAN RIGHTS. All rights and remedies of the Lender under this Agreement
are subject to the rights of Elan International Services, Ltd. and its
affiliates as set forth in that certain Subscription, Joint Development and
Operating Agreement, dated as of October 20, 1999, and all documents executed
pursuant thereto (including that certain License Agreement between Technologies
and Photogen Newco, Ltd., now known as Sentigen, Ltd.).

     11. EXPENSE OF ENFORCEMENT. Borrowers shall pay and reimburse Lender for
all costs, expenses and attorney's fees incurred in seeking to protect or
perfect a security interest in the Collateral, in enforcing the terms of this
Agreement or the Note, or in defending any action or proceeding relating hereto
or to the Collateral, including without limitation, appraiser's fees,
transportation expenses, documentary and expert evidence fees and costs and
stenographer's charges, including those incurred in connection with: any
bankruptcy actions or proceedings; preparations for the commencement of any
action, proceeding or suit; and preparations for the defense of any threatened
action, proceeding or suit which might affect the Collateral, whether or not
actually filed. All such costs, expenses and fees shall become additional
Indebtedness secured by the Collateral and shall become immediately due and
payable by Borrowers as and when paid or incurred by Lender.

     12. SALE OF COLLATERAL. All or any part of the Collateral may be sold,
licensed or otherwise transferred in any transaction duly approved by the Board
of Directors of Photogen Technologies, Inc. Such a transaction may include a
reorganization pursuant to which certain assets related to Photogen's
therapeutic technologies may be transferred to an entity controlled by
Photogen's five founding stockholders in exchange for all their shares of
Technologies stock.

     13. ASSIGNMENT. If at any time, by assignment or otherwise, Lender assigns
or transfers any rights or benefits hereunder such transfer shall include all of
Lender's rights and powers under this Agreement with respect to said
Indebtedness, Collateral, or other security transferred and the transferee shall
become vested with all the same rights and powers, whether or not they are
specifically referred to in the instrument of transfer. If and to the extent
that Lender retains any other Indebtedness or Collateral or other security,
Lender will continue to have the rights and powers herein set forth with respect
thereto.

     14. NO WAIVER. No delay or failure by Lender to insist upon the strict
performance of any term hereof or of the Note or to exercise any right, power or
remedy provided for herein or therein as a consequence of an Event of Default
hereunder or thereunder, and no acceptance of any payment of the principal,
interest, or premium, if any, on the Indebtedness during the continuance of any
such Event of Default, shall constitute a waiver of any such term, such Event of
Default, or such right, power or remedy. The exercise by Lender of any right,
power or remedy conferred upon Lender by this or the Note or by law or equity
shall not preclude any other or further exercise thereof or the exercise of any
other right, power or remedy. No waiver of any Event of Default hereunder shall
affect or alter this Agreement, which shall continue in full force and effect
with respect to any other then existing or subsequent Events of Default.


                                      -9-
<Page>


     15. AMENDMENT. This Agreement shall not be amended, modified or terminated
orally but may only be amended, modified or terminated pursuant to written
agreement between Borrowers and Lender.

     16. FURTHER ASSURANCES. From and after the date hereof, each of the parties
hereto agree to do or cause to be done such further acts and things and deliver
or cause to be delivered to each other such additional assignments, agreements,
powers and instruments, as each may reasonably require or deem advisable to
carry into effect the purposes of this Agreement and the Other Agreements.

     17. NOTICES. All notices, demands and requests of any kind to be delivered
to any party in connection with this Agreement shall be in writing and shall be
deemed to have been duly given if personally or hand delivered or if sent by an
internationally-recognized overnight delivery or by registered or certified
mail, return receipt requested and postage prepaid, or by facsimile transmission
addressed as set forth beneath each parties signature below or to such other
address as the party to whom notice is to be given may have furnished to the
other party hereto in writing in accordance with provisions of this Section 17.
Any such notice or communication shall be deemed to have been effectively given
(i) in the case of personal or hand delivery, on the date of such delivery, (ii)
in the case of an internationally-recognized overnight delivery service, on the
second business day after the date when sent, (iii) in the case of mailing, on
the fifth business day following that day on which the piece of mail containing
such communication is posted, and (iv) in the case of facsimile transmission, on
the date of telephone confirmation of receipt.

     18. SEVERABILITY. If any provision in this Agreement or the Note is held by
a court of law to be in violation of any applicable local, state or federal
ordinance, statute, law, administration or judicial decision, or public policy,
and if such court should declare such provision of this Agreement to be illegal,
invalid, unlawful, void; voidable, or unenforceable as written, then such
provision shall be given full force and effect to the fullest possible extent
that is legal, valid and enforceable. The remainder of this Agreement shall be
construed as if such illegal, invalid, unlawful, void, voidable or unenforceable
provision was not contained therein. The rights, obligations and interest of the
Borrowers and the holder hereof under the remainder of this Agreement shall
continue in full force and effect.

     19. GOVERNING LAW/VENUE. This Agreement shall be governed by, and construed
in accordance with, the internal laws of the State of Illinois without regard to
its provisions on conflict of laws. Borrowers irrevocably agree that, in
Lender's sole and absolute discretion, all actions, suits and proceedings in any
manner or way arising out of or in respect to this Agreement, any documents
executed concurrently herewith, or the Collateral, shall be litigated in state
or federal courts within the County of Cook, or having jurisdiction with respect
to said county. Borrowers expressly submit to the jurisdiction of any state or
federal court located within or having jurisdiction over said county. Borrowers
waive any right it tray have to change the venue of any litigation brought in
accordance herewith. Borrowers hereby waive a right to a jury trial in any
litigation brought with respect to this Agreement or the transactions
contemplated herein.



                                      -10-
<Page>


     20. NO PARTY DEEMED DRAFTER. Borrowers acknowledge and agree that Borrowers
have been afforded the opportunity to review and approve this Agreement and to
have this Agreement reviewed and approved by counsel of Borrowers' choice, that
this Agreement constitutes an arms-length transaction between the parties, and
that neither Borrowers nor Lender shall be deemed the drafter of this Agreement
for purposes of construing the terms hereof.

     21. TIME OF ESSENCE. Time is of the essence hereof.





                            [SIGNATURE PAGE FOLLOWS]





                                      -11-
<Page>




     IN WITNESS WHEREOF, this Loan and Security Agreement is executed and
effective as of the date first set forth above.


<Table>
<Caption>

<S>                                                          <C>
Photogen Technologies, Inc.                                  Photogen, Inc.



By: /s/ Brooks Boveroux                                      By:  /s/ Brooks Boveroux
   -----------------------------------------                      -------------------------------------------
Its:    CFO                                                  Its:
    ----------------------------------------                      -------------------------------------------

                                                             Tannebaum, LLC, by its Manager STRO, LLC



                                                             By:  /s/ Robert Weinstein
                                                                  -------------------------------------------
                                                             Its:
                                                                  -------------------------------------------

Address for notice to Borrowers:                             Address for notice to Lender:

Photogen Technologies, Inc.                                  875 North Michigan Avenue
140 Union Square Drive                                       Suite 2930
New Hope, PA 18938                                           Chicago, IL  60611-1901
Attn:  Brooks Boveroux, CFO                                  Attention:   Robert J. Weinstein, M.D.
                                                                          Manager of STRO, LLC
</Table>




                 [SIGNATURE PAGE TO LOAN AND SECURITY AGREEMENT]