<PAGE>
                                AMENDED AND RESTATED
                   CERTIFICATE OF DESIGNATIONS, PREFERENCES, AND
                                       RIGHTS
                                         OF
                              SERIES A PREFERRED STOCK
                                         OF
                            PHOTOGEN TECHNOLOGIES, INC.

                      (Pursuant to Title 7, Chapter 78 of the
                              Nevada Revised Statutes)

     We, the undersigned, for the purpose of amending and restating the
Certificate of Designations, Preferences, and Rights of Series A Preferred
Stock of Photogen Technologies, Inc. filed October 20, 1999 with the
Secretary of State of Nevada and subject to the requirements of Title 7,
Chapter 78 of the Nevada Revised Statutes, and the acts amendatory thereof,
and hereinafter sometimes referred to as the General Corporation Law of the
State of Nevada, do hereby adopt and make the following Amended and Restated
Certificate of Designations, Preferences, and Rights of Series A Preferred
Stock of Photogen Technologies, Inc.:

          FIRST:    The original Certificate of Designations, Preferences,
     and Rights of Series A Preferred Stock of Photogen Technologies, Inc. as
     filed with the Secretary of State of Nevada and attached hereto is
     hereby amended by the Amended and Restated Certificate of Designations,
     Preferences, and Rights of Series A Preferred Stock of Photogen
     Technologies, Inc. as set forth below.

          SECOND:   The sole record and beneficial holder of Series A
     Preferred Stock approved the Amended and Restated Certificate of
     Designations, Preferences, and Rights of Series A Preferred Stock on
     October 27, 1999

          THIRD:    That pursuant to the authority conferred upon the Board of
     Directors by the Restated Articles of Incorporation of the said
     Corporation, the said Board of Directors on October 25, 1999 adopted the
     following resolution, pursuant to Article Fourth of the Corporation's
     Restated Articles of Incorporation and Title 7, Chapter 78 of the Nevada
     Revised Statutes, amending the terms of the series of shares of Preferred
     Stock designated as Series A Preferred Stock:

                    "RESOLVED, that pursuant to the authority vested in the
     Board of Directors of the corporation by the Restated Articles of
     Incorporation, the Board of Directors does hereby provide for the issuance
     of a series of Preferred Stock, $0.01 par value, of the Corporation, to be
     designated "Series A Preferred Stock", initially consisting of 12,015
     shares, and to the extent that the designations, powers, preferences and
     relative and other special rights and the qualifications, limitations
     and restrictions of the Series A Preferred Stock are not stated and
     expressed in the Restated Articles of Incorporation, the Board of
     Directors does hereby fix and herein state and express such
     designations, powers, preferences and relative and other special rights
     and the qualifications, limitations and restrictions thereof, as follows
     (all terms used herein which are defined in the Restated Articles of
     Incorporation shall be deemed to have the meanings provided therein):

<PAGE>

          1.   DESIGNATION.  12,015 shares of Preferred Stock shall be
     designated and known as the "SERIES A PREFERRED STOCK."  Such number of
     shares may be increased or decreased by resolution of the Board of
     Directors after obtaining the consent of a majority in interest of the
     holder(s) of the then-outstanding shares of Series A Preferred Stock;
     provided, that no decrease shall reduce the number of shares of Series A
     Preferred Stock to a number less than the number of shares then
     outstanding plus the number of such shares issuable upon exercise of
     outstanding rights, options or warrants or upon conversion of
     outstanding securities issued by the Corporation.

          2.   DIVIDEND PROVISIONS.

               a.   From and after the date hereof, when and if the Board of
     Directors shall declare a dividend or distribution payable with respect
     to the then-outstanding shares of Common Stock of the Corporation, the
     holders of the Series A Preferred Stock shall be entitled to the amount
     of dividends per share in the same form as such Common Stock dividends
     that would be payable on the largest number of whole shares of Common
     Stock into which a holder's aggregate shares of Series A Preferred Stock
     could then be converted pursuant to Section 4 hereof (such number to be
     determined as of the record date for the determination of holders of
     Common Stock entitled to receive such dividend).

               b.   In addition to Section 2(a) above, each share of Series A
     Preferred Stock, for a period of six years from the date of first
     issuance of the Series A Preferred Stock, shall be entitled to receive a
     mandatory dividend equal to 7.0% per year of the Original Issue Price
     (as defined below) thereof. Such dividend shall (1) be cumulative and
     shall compound on a semi-annual basis, the first compounding to commence
     six months from the date hereof and (2) be payable semi-annually solely
     by the issuance of additional shares of Series A Preferred Stock, at a
     price per share equal to the Original Issue Price thereof, and not in
     cash.  Fractional shares of Series A Preferred Stock shall be issuable
     for purposes hereunder.

     3.   SENIORITY; LIQUIDATION PREFERENCE.

          a.   The Series A Preferred Stock, as to its liquidation preference,
     shall rank senior to or PARI PASSU with (but as to PARI PASSU only, as
     agreed to by a majority in interest of the outstanding shares of Series A
     Preferred Stock) any future class or series of Preferred Stock issued by
     the Company and senior to the Company's Common Stock.

          b.   In the event of any liquidation, dissolution or winding-up of
      the affairs of the Corporation, whether voluntary or involuntary,
      (collectively, a "LIQUIDATION"), before any payment of cash or
      distribution of other property shall be made to the holders of the
      Common Stock or any other class or series of stock subordinate in
      liquidation preference to the Series A Preferred Stock, the holders of
      the Series A Preferred Stock shall be entitled to receive out of the
      assets of the Corporation legally available for distribution to its
      shareholders, the Original Issue Price per share (as appropriately
      adjusted for any combinations or divisions or similar recapitalizations
      affecting the Series A Preferred Stock after issuance) and accrued and
      unpaid dividends thereon (the "SERIES A LIQUIDATION PREFERENCE"). As
      used herein, the "ORIGINAL ISSUE PRICE" per share is $1,000.

<PAGE>

          c.   If, upon any Liquidation, the assets of the Corporation
available for distribution to its shareholders shall be insufficient to pay
the holders of the Series A Preferred Stock the full amounts to which they
shall be entitled, the holders of the Series A Preferred Stock shall share
ratably in any distribution of assets in proportion to the respective amounts
which would be payable to them in respect of the shares held by them if all
amounts payable to them in respect of such were paid in full pursuant to
Section 3(b).

          d.   After the distributions described in Section 3(c) above have
been paid, subject to the rights of other series of preferred stock that may
from time to time come into existence, the remaining assets of the
Corporation available for distribution to shareholders shall be distributed
among the holders of Common Stock PRO RATA based on the number of shares of
Common Stock held by each.

     4.   CONVERSION.  The holders of the Series A Preferred Stock shall have
conversion rights, through and including the Conversion Termination Date (as
defined below), as follows (the "CONVERSION RIGHTS"):

          a.   RIGHT TO CONVERT.

               (i)  Each share of Series A Preferred Stock shall be
     convertible, at the option of the holder thereof, at any time that is
     two years after the issuance thereof, at the office of the Corporation
     or any transfer agent for such stock, into such number of fully paid and
     non-assessable shares of Common Stock as is determined by dividing (x)
     the sum of the Original Issue Price of such share of Series A Preferred
     Stock (including all shares issued as dividends thereon) and all accrued
     and unpaid dividends thereon by (y) the Series A Conversion Price (as
     defined below). The "SERIES A CONVERSION PRICE" shall initially be
     $21.17 and shall be subject to adjustment as set forth below in this
     Section 4(a); provided, however, that the Series A Conversion Price
     shall not exceed $21.17.

               (ii)  Before any holder of Series A Preferred Stock shall be
     entitled to convert such shares into shares of Common Stock, such holder
     shall surrender the certificate or certificates therefor, duly endorsed,
     at the office of the Corporation or of any transfer agent for the Series
     A Preferred Stock, and shall give written notice to the Corporation at
     its principal corporate office, of the election to convert the same and
     shall state therein the name or names in which the certificate or
     certificates for shares of Common Stock are to be issued.  The
     Corporation shall, as soon as practicable thereafter, issue and deliver
     at such office to such holder of Series A Preferred Stock, or to the
     nominee or nominees of such holder, a certificate or certificates for
     the number of shares of Common Stock to which such holder shall be
     entitled as set forth above.  Such conversion shall be deemed to have
     been made immediately prior to the close of business on the date of such
     surrender of the shares of Series A Preferred Stock to be converted, and
     the person or persons entitled to receive the shares of Common Stock
     issuable upon such conversion shall be treated for all purposes as the
     record holder or holders of such shares of Common Stock as of such date.

<PAGE>

               (iii)  In the event the Corporation should at any time fix a
     record date for the effectuation of a split or subdivision of the
     outstanding shares of Common Stock or the determination of holders of
     Common Stock entitled to receive a dividend or other distribution
     payable in additional shares of Common Stock or other securities or
     rights convertible into, or entitling the holder thereof to receive
     directly or indirectly, additional shares of Common Stock (hereinafter
     referred to as "COMMON STOCK EQUIVALENTS") without payment of any
     consideration by such holder for the additional shares of Common Stock
     or the Common Stock Equivalents (including the additional shares of
     Common Stock issuable upon conversion or exercise thereof) or with
     payment that is less than the then-market price of the Common Stock
     (including, in the case of Common Stock Equivalents, on an as-converted
     basis) then, as of such record date (or the date of such dividend
     distribution, split or subdivision if no record date is fixed), the
     Series A Conversion Price of the Series A Preferred Stock shall be
     appropriately decreased so that the number of shares of Common Stock
     issuable on conversion of each share of such series shall be increased
     in proportion to such increase of the aggregate of (a) shares of Common
     Stock outstanding and (b) those issuable with respect to such Common
     Stock Equivalents, with the number of shares issuable with respect to
     Common Stock Equivalents determined from time to time as provided in
     Section 4(a)(v) below.

               (iv) If the number of shares of Common Stock outstanding at
     any time is decreased by a combination of the outstanding shares of
     Common Stock, then, following the record date of such combination, the
     Series A Conversion Price for the Series A Preferred Stock shall be
     appropriately increased so that the number of shares of Common Stock
     issuable on conversion of each share of such series shall be decreased
     in proportion to such decrease in outstanding shares.

               (v)  The following provisions shall apply for purposes of this
     Section 4(a):

                    (A)  The aggregate maximum number of shares of Common
     Stock deliverable upon conversion or exercise of Common Stock
     Equivalents (assuming the satisfaction of any conditions to
     convertibility or exercisability, including, without limitation, the
     passage of time, but without taking into account potential antidilution
     adjustments) shall be deemed to have been issued at the time such Common
     Stock Equivalents were issued.

                    (B)  In the event of any change in the number of shares
     of Common Stock deliverable or in the consideration payable to the
     Corporation upon conversion or exercise of such Common Stock Equivalents
     including, but not limited to, a change resulting from the antidilution
     provisions thereof, the Series A Conversion Price of the Series A
     Preferred Stock, to the extent in any way affected by or computed using
     such Common Stock Equivalents, shall be recomputed to reflect such
     change, but no further adjustment shall be made for the actual issuance
     of Common Stock or any payment of such consideration upon the exercise
     of any such options or rights or the conversion or exchange of such
     securities.

                    (C)  Upon the termination or expiration of the
     convertibility or exercisability of any such Common Stock Equivalents,
     the Series A Conversion Price of the Series A Preferred Stock, to the
     extent in any way affected by or computed using such Common Stock
     Equivalents, shall be recomputed to reflect the issuance of only the

<PAGE>

     number of shares of Common Stock (and Common Stock Equivalents which
     remain convertible or exercisable) actually issued upon the conversion
     or exercise of such Common Stock Equivalents.

     5.   EXCHANGE RIGHT. Provided that (a) all shares of Series A Preferred
Stock initially issued and sold by the Corporation to EIS have not been
converted and (b) the Exchange Termination Date (as defined below) shall not
have occurred, the holders of the Series A Preferred Stock (acting by act of
the majority holders thereof) shall have the right to exchange all of their
shares of Series A Preferred Stock (the "EXCHANGE RIGHT") of the Corporation
for such number of shares of Common Shares (as adjusted for any combinations
or divisions or similar recapitalizations) of PHOTOGEN NEWCO LTD., a Bermuda
exempted limited liability company ("NEWCO") held by the Corporation, so
that, after giving effect to the exercise of the Exchange Right, EIS and the
Corporation will each hold 50% of the total outstanding share capital of
Newco assuming that neither EIS nor the Corporation has sold any shares of
Newco; provided, that if EIS exercises the Exchange Right prior to a date
that is three years after the date hereof, the Corporation shall deliver to
Newco for exchange the number of Common Shares of Newco that would otherwise
be delivered to EIS pursuant to this Section 5, and EIS shall receive from
Newco, upon the exchange of such Common Shares, a number of shares of a
newly-created non-voting convertible preferred stock of Newco equal to such
number of Common Shares delivered to Newco by the Corporation.  Such
non-voting preferred stock shall be convertible into Common Shares of Newco
on a one-for-one basis at any time after such three-year period.

          Upon exercise of the Exchange Right, the shares of Series A
Preferred Stock originally purchased from the Corporation, but not including
any of the accrued and unpaid dividends thereon, shall be canceled and shall
no longer be entitled to any rights in the Corporation.

          If any shares of the Series A Preferred Stock are converted
pursuant to Section 4(a), to shares of Common Stock, the Exchange Right with
respect to the shares of Series A Preferred Stock originally purchased from
the Corporation, but not including any of the accrued and unpaid dividends
thereon, shall be canceled and shall no longer be entitled to any rights in
the Corporation.

          In order to exercise the Exchange Right, the holders shall provide
written notice thereof to the Corporation, setting forth (a) the fact that
such holders intend to exercise the Exchange Right, and (b) the proposed date
for such exercise (the "EXERCISE DATE"), which shall be between 10 and 30
days after the date of such notice, PROVIDED, HOWEVER, that if the
Corporation shall deliver the holders a written request to delay the date for
such exercise by no more than 45 days, the Exercise Date will be as set forth
in that request. During the period after the receipt of such written request,
and before the Exercise Date, the holders shall negotiate with the
Corporation in good faith an alternative mechanism for the transfer of the
Common Shares or Preferred Stock of Newco that will reduce the Corporation's
tax liability, provided that the holders shall not be required to agree to
any transaction which is financially disadvantageous to them.  On the
Exercise Date, (y) the holders shall tender their shares of Series A
Preferred Stock

<PAGE>

to the Corporation for cancellation, and (z) the Corporation shall cause to
be delivered to EIS, acting on behalf of such holders, such shares of Newco.
The holders and the Corporation shall take all other necessary or appropriate
actions in connection with or to effect such closing.

     6.   TERMINATION DATE.

          a.   The rights of the holders to convert the shares of Series A
Preferred Stock into shares of Common Stock, shall terminate and be of no
further force and effect on the date that is six years after the date of the
first issuance of any shares of Series A Preferred Stock hereunder (the
"CONVERSION TERMINATION DATE").

          b.   The rights of the holders to exercise the Exchange Right shall
terminate and be of no further force and effect on the date that is six
years after the date of the first issuance of any shares of the Series A
Preferred Stock hereunder (the "EXCHANGE TERMINATION DATE").

     7.   OTHER DISTRIBUTIONS.  On or prior to the Conversion Termination
Date, in the event the Corporation shall declare a distribution payable in
securities of other persons, evidences of indebtedness issued by the
Corporation or other persons, assets (excluding cash dividends) or options or
rights not referred to in Section 4, then, in each such case for the purpose
of this Section 7, the holders of the Series A Preferred Stock shall be
entitled to a proportionate share of any such distribution as though they
were the holders of the number of shares of Common Stock of the Corporation
into which their shares of Series A Preferred Stock would be convertible as
of the record date fixed for the determination of the holders of Common Stock
of the Corporation entitled to receive such distribution.

     8.   RECAPITALIZATIONS.  On or prior to the Conversion Termination Date,
if at any time or from time to time there shall be a recapitalization of the
Common Stock (other than a subdivision, combination or merger or sale of
assets provided for in Section 3 or Section 4 hereof) provision shall be made
so that the holders of the Series A Preferred Stock shall thereafter be
entitled to receive upon conversion of the Series A Preferred Stock the
number of shares of stock or other securities or property of the Corporation
or otherwise, to which a holder of Common Stock deliverable upon conversion
would have been entitled on such recapitalization.  In any such case,
appropriate adjustment shall be made in the application of the provisions of
Section 4 with respect to the rights of the holders of the Series A Preferred
Stock after the recapitalization to the end that the provisions of Section 4
(including adjustment of the Series A Conversion Price then in effect and the
number of shares purchasable upon conversion of the Series A Preferred Stock)
shall be applicable after that event as nearly equivalent as may be
practicable.

     9.   NO IMPAIRMENT.  The Corporation will not, by amendment of its
Articles of Incorporation or through any reorganization, recapitalization,
transfer of assets, consolidation, merger, dissolution, issuance or sale of
securities or any other voluntary action, avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed
hereunder by the Corporation, but will at all times in good faith assist in
the carrying out of all the provisions hereof and in the taking of all such
action as may be necessary or appropriate in order to protect the Series A
Conversion Rights and Exchange Right of the holders of the Series A Preferred
Stock against impairment.

     10.  NO FRACTIONAL SHARES AND CERTIFICATE AS TO ADJUSTMENTS.

<PAGE>

          a.   No fractional shares shall be issued upon the conversion of
any share or shares of the Series A Preferred Stock, and the number of shares
of Common Stock to be issued shall be rounded to the nearest whole share.
Whether or not fractional shares are issuable upon such conversion shall be
determined on the basis of the aggregate number of shares of Series A
Preferred Stock each holder is at the time converting into Common Stock and
the aggregate number of shares of Common Stock issuable to each such holder
upon such conversion.  No fractional shares shall be issued upon the
conversion of any share or shares of the Series A Preferred Stock, and the
number of shares of Common Stock to be issued shall be rounded to the nearest
whole share.  Whether or not fractional shares are issuable upon such
conversion shall be determined on the basis of the total number of shares of
Series A Preferred Stock the holder is at the time converting into Common
Stock and the number of shares of Common Stock issuable upon such aggregate
conversion.

          b.   Upon the occurrence of each adjustment or readjustment of the
Series A Conversion Price pursuant to Section 4, the Corporation, at its
expense, shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and prepare and furnish to each holder of shares of
Series A Preferred Stock a certificate setting forth such adjustment or
readjustment and showing in detail the facts upon which such adjustment or
readjustment is based.  The Corporation shall, upon the written request at
any time of any holder of Series A Preferred Stock, furnish or cause to be
furnished to such holder a like certificate setting forth (i) such adjustment
and readjustment, (ii) the Series A Conversion Price at the time in effect,
and (iii) the number of shares of Common Stock and the amount, if any, of
other property which at the time would be received upon the conversion of a
share of Series A Preferred Stock.

     11.  RESERVATION OF STOCK ISSUABLE UPON CONVERSION.  The Corporation
shall at all times reserve and keep available out of its authorized but
unissued shares of Common Stock, solely for the purpose of effecting the
conversion of the shares of the Series A Preferred Stock, such number of its
shares of Common Stock that shall from time to time be sufficient to effect
the conversion of all outstanding shares of the Series A Preferred Stock; and
if at any time the number of authorized but unissued shares of Common Stock
not otherwise reserved for issuance shall not be sufficient to effect the
conversion of all then outstanding shares of the Series A Preferred Stock, in
addition to such other remedies as shall be available to the holders of such
Series A Preferred Stock, the Corporation will take such corporate action
that may, in the opinion of its counsel, be necessary to increase its
authorized but unissued shares of Common Stock to such number of shares as
shall be sufficient for such purposes, including without limitation, engaging
in best efforts to obtain the requisite shareholder approval of any necessary
amendment to its Articles of Incorporation.

     12.  NOTICES.  Any notice required by the provisions hereof to be given
to the holders of shares of Series A Preferred Stock shall be deemed given on
the date of service if served personally on the party to whom notice is to be
given, or on the date of transmittal of services by facsimile transmission to
the party to whom notice is to be given, and addressed to each holder of
record at his address appearing on the books of the Corporation.

<PAGE>

     13.  VOTING RIGHTS.  Subject to Section 14 below, holders of Series A
Preferred Stock shall not be entitled to vote, including with respect to the
election of directors of the Corporation.

     14.  PROTECTIVE PROVISIONS.  Subject to the rights of any series of
preferred stock that may from time to time come into existence, so long as
any shares of Series A Preferred Stock are outstanding, the Corporation shall
not without first obtaining the approval (by vote or written consent, as
provided by law) of the holders of at least a majority of the
then-outstanding shares of Series A Preferred Stock, voting separately as a
series:

          a.   amend its Restated Articles of Incorporation so as to affect
adversely the shares of Series A Preferred Stock or any holder thereof
(including by creating any additional classes or series of preferred stock
with a liquidation preference senior to or PARI PASSU with the Series A
Preferred Stock); or

          b.   change the rights of the holders of the Series A Preferred
Stock in any other respect.

     15.  STATUS OF CONVERTED STOCK.  In the event any shares of Series A
Preferred Stock shall be converted pursuant to Section 4 or exchanged
pursuant to Section 5 hereof, the shares so converted or exchanged shall be
canceled and shall not be reissuable by the Corporation.  The Restated
Articles of Incorporation of the Corporation shall be appropriately amended
to effect the corresponding reduction in the Corporation's authorized capital
stock."

<PAGE>

          IN WITNESS WHEREOF, said Photogen Technologies, Inc. has caused
this Amended Certificate of Designation to be signed by John Smolik, its
President and Timothy Scott, its Assistant Secretary this 2nd day of
November, 1999.

                                   PHOTOGEN TECHNOLOGIES, INC.

                                   By:  /s/ John Smolik
                                        ------------------
                                        Name:  John Smolik
                                        Title: President

                                   By:  /s/ Timothy Scott
                                        ------------------
                                        Name: Timothy Scott
                                        Title: Assistant Secretary



<PAGE>

STATE OF Tennessee       )
         ----------------
                         )SS.
COUNTY OF Knox           )
          ---------------

          On this 2nd day of November, 1999, personally appeared before me, a
Notary Public in and for the State and County aforesaid, John Smolik, known
to me to be the person described in and did say that he is the President of
Photogen Technologies, Inc., a Nevada corporation, and that the foregoing
Amended and Restated Certificate of Designations, Preferences, and Rights of
Series A Preferred Stock was signed on behalf of said corporation by
authority of its board of directors, and said John Smolik acknowledged to me
that said instrument to be the free act and deed of said corporation.

          WITNESS my hand and official seal, the day and year first above
written.


                                   /s/
                                   ---------------------------------------
                                   Notary Public
(Notarial Seal)


STATE OF Tennessee       )
         ----------------
                         )SS.
COUNTY OF Knox           )
          ---------------

          On this 2nd day of November, 1999, personally appeared before me, a
Notary Public in and for the State and County aforesaid, Timothy Scott, known
to me to be the person described in and did say that he is the Assistant
Secretary of Photogen Technologies, Inc., a Nevada corporation, and that the
foregoing Amended and Restated Certificate of Designations, Preferences, and
Rights of Series A Preferred Stock was signed on behalf of said corporation
by authority of its board of directors, and said Timothy Scott acknowledged
to me that said instrument to be the free act and deed of said corporation.

          WITNESS my hand and official seal, the day and year first above
written.

                                   /s/
                                   ---------------------------------------
                                   Notary Public

(Notarial Seal)