<PAGE>

                                                                     EXHIBIT 4.1



                          REGISTRATION RIGHTS AGREEMENT



                                     between



                            IMPAX LABORATORIES, INC.


                                   as Issuer,


                                       and


                          CITIGROUP GLOBAL MARKETS INC.

                   as representative of the Initial Purchasers


                            Dated as of April 5, 2004











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         REGISTRATION RIGHTS AGREEMENT dated as of April 5, 2004 between IMPAX
Laboratories, Inc., a Delaware corporation (the "Company") and Citigroup Global
Markets Inc. acting as representative for the several initial purchasers (the
"Initial Purchasers") named in Schedule I to the Purchase Agreement dated March
30, 2004 (the "Purchase Agreement"), between the Company and the Initial
Purchasers. In order to induce the Initial Purchasers to enter into the Purchase
Agreement, the Company has agreed to provide the registration rights set forth
in this Agreement.

         The Company agrees with the Initial Purchasers, (i) for their benefit
as Initial Purchasers and (ii) for the benefit of the beneficial owners
(including the Initial Purchasers) from time to time of the Debentures (as
defined herein) and the beneficial owners from time to time of the Underlying
Common Stock (as defined herein) issued upon conversion of the Debentures (each
of the foregoing a "Holder" and together the "Holders"), as follows:

         Section 1. Definitions. Capitalized terms used herein without
definition shall have their respective meanings set forth in the Purchase
Agreement. As used in this Agreement, the following terms shall have the
following meanings:

         "Affiliate" means with respect to any specified person, an "affiliate,"
as defined in Rule 144, of such person.

         "Amendment Effectiveness Deadline Date" has the meaning set forth in
Section 2(d) hereof.

         "Business Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday that is not a day on which banking institutions in The City of New York
are authorized or obligated by law or executive order to close.

         "Common Stock" means the shares of common stock, $0.01 par value per
share, of the Company and any other shares of common stock as may constitute
"Common Stock" for purposes of the Indenture, including the Underlying Common
Stock.

         "Conversion Price" has the meaning assigned such term in the Indenture.

         "Damages Accrual Period" has the meaning set forth in Section 2(e)
hereof.

         "Damages Payment Date" means each April 1 and October 1.

         "Debentures" means the 1.250% Convertible Senior Subordinated
Debentures Due 2024 of the Company to be purchased pursuant to the Purchase
Agreement.




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         "Deferral Notice" has the meaning set forth in Section 3(h) hereof.

         "Deferral Period" has the meaning set forth in Section 3(h) hereof.

         "Effectiveness Deadline Date" has the meaning set forth in Section 2(a)
hereof.

         "Effectiveness Period" means the period commencing on the date hereof
and ending on the date that all Registrable Securities have ceased to be
Registrable Securities.

         "Event" has the meaning set forth in Section 2(e) hereof.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended,
and the rules and regulations of the SEC promulgated thereunder.

         "Filing Deadline Date" has the meaning set forth in Section 2(a)
hereof.

         "Holder" has the meaning set forth in the second paragraph of this
Agreement.

         "Indenture" means the Indenture, dated as of April 5, 2004, between the
Company and Wachovia Bank, N.A., as trustee, pursuant to which the Debentures
are being issued.

         "Initial Purchasers" has the meaning set forth in the preamble hereof.

         "Initial Shelf Registration Statement" has the meaning set forth in
Section 2(a) hereof.

         "Issue Date" means April 5, 2004.

         "Liquidated Damages Amount" has the meaning set forth in Section 2(e)
hereof.

         "Material Event" has the meaning set forth in Section 3(h) hereof.

         "Notice and Questionnaire" means a written notice delivered to the
Company containing the information called for by the Selling Securityholder
Notice and Questionnaire attached as Annex A to the Offering Memorandum of the
Company dated March 31, 2004 relating to the Debentures.

         "Notice Holder" means, on any date, any Holder that has delivered a
Notice and Questionnaire to the Company on or prior to such date.

         "Purchase Agreement" has the meaning set forth in the preamble hereof.




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         "Prospectus" means the prospectus included in any Registration
Statement (including, without limitation, a prospectus that discloses
information previously omitted from a prospectus filed as part of an effective
registration statement in reliance upon Rule 430A promulgated under the
Securities Act), as amended or supplemented by any amendment or prospectus
supplement, including post-effective amendments, and all materials incorporated
by reference or explicitly deemed to be incorporated by reference in such
Prospectus.

         "Record Holder" means with respect to any Damages Payment Date relating
to any Debentures or Underlying Common Stock as to which any Liquidated Damages
Amount has accrued, the registered holder of such Debenture or Underlying Common
Stock on the March 15 immediately preceding a Damages Payment Date occurring on
a April 1, and on the September 15 immediately preceding a Damages Payment Date
occurring on a October 1.

         "Registrable Securities" means the Debentures until such Debentures
have been converted into or exchanged for the Underlying Common Stock and, at
all times subsequent to any such conversion, the Underlying Common Stock and any
securities into or for which such Underlying Common Stock has been converted or
exchanged, and any security issued with respect thereto upon any stock dividend,
split or similar event until, in the case of any such security, (A) the earliest
of (i) its effective registration under the Securities Act and resale in
accordance with the Registration Statement covering it, (ii) expiration of the
holding period that would be applicable thereto under Rule 144(k) or (iii) its
transfer pursuant to Rule 144 under the Securities Act, and (B) as a result of
the event or circumstance described in any of the foregoing clauses (i) through
(iii), the legend with respect to transfer restrictions required under the
Indenture is removed or removable in accordance with the terms of the Indenture
or such legend, as the case may be.

         "Registration Statement" means any registration statement of the
Company that covers any of the Registrable Securities pursuant to the provisions
of this Agreement, including the Prospectus, amendments and supplements to such
registration statement, including post-effective amendments, all exhibits and
all materials incorporated by reference or explicitly deemed to be incorporated
by reference in such registration statement.

         "Restricted Securities" means "Restricted Securities" as defined in
Rule 144.

         "Rule 144" means Rule 144 under the Securities Act, as such Rule may be
amended from time to time, or any similar rule or regulation hereafter adopted
by the SEC.





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         "Rule 144A" means Rule 144A under the Securities Act, as such Rule may
be amended from time to time, or any similar rule or regulation hereafter
adopted by the SEC.

         "SEC" means the United States Securities and Exchange Commission.

         "Securities Act" means the Securities Act of 1933, as amended, and the
rules and regulations promulgated by the SEC thereunder.

         "Shelf Registration Statement" has the meaning set forth in Section
2(a) hereof.

         "Special Counsel" means Davis Polk & Wardwell or one such other
successor counsel as shall be specified in writing to the Company by the Holders
of a majority of the Registrable Securities, but which may, with the written
consent of the Initial Purchasers (which shall not be unreasonably withheld), be
another nationally recognized law firm experienced in securities law matters
designated by the Company, the reasonable fees and expenses of which will be
paid by the Company pursuant to Section 5 hereof. For purposes of determining
the holders of a majority of the Registrable Securities in this definition,
Holders of Debentures shall be deemed to be the Holders of the number of shares
of Underlying Common Stock into which such Debentures are or would be
convertible as of the date the consent is requested.

         "Subsequent Shelf Registration Statement" has the meaning set forth in
Section 2(b) hereof.

         "TIA" means the Trust Indenture Act of 1939, as amended.

         "Trustee" means Wachovia Bank, N.A., the Trustee under the Indenture.

         "Underlying Common Stock" means the Common Stock into which the
Debentures are convertible or issued upon any such conversion.

         Section 2. Shelf Registration. (a) The Company shall prepare and file
or cause to be prepared and filed with the SEC, as soon as practicable but in
any event by the date that is ninety (90) days after the Issue Date (the "Filing
Deadline Date"), a Registration Statement for an offering to be made on a
delayed or continuous basis pursuant to Rule 415 of the Securities Act (a "Shelf
Registration Statement") registering the resale from time to time by Holders
thereof of all of the Registrable Securities (the "Initial Shelf Registration
Statement"). The Initial Shelf Registration Statement shall be on Form S-3 or
another appropriate form permitting registration of such Registrable Securities
for resale by such Holders in accordance with the methods of distribution
elected by the Holders and permitted by applicable law and set forth in the






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Initial Shelf Registration Statement. The Company shall use its commercially
reasonable efforts to cause the Initial Shelf Registration Statement to be
declared effective under the Securities Act as promptly as is practicable but in
any event by the date (the "Effectiveness Deadline Date") that is one hundred
eighty (180) days after the Issue Date, and to keep the Initial Shelf
Registration Statement (or any Subsequent Shelf Registration Statement)
continuously effective under the Securities Act until the expiration of the
Effectiveness Period. At the time the Initial Shelf Registration Statement is
declared effective, each Holder that became a Notice Holder on or prior to the
date ten (10) Business Days prior to such time of effectiveness shall be named
as a selling securityholder in the Initial Shelf Registration Statement and the
related Prospectus in such a manner as to permit such Holder to deliver such
Prospectus to purchasers of Registrable Securities in accordance with applicable
law. None of the Company's security holders (other than the Holders of
Registrable Securities) shall have the right to include any of the Company's
securities in the Shelf Registration Statement.

         (b) Following the date that the Initial Shelf Registration Statement is
declared effective, if the Initial Shelf Registration Statement or any
Subsequent Shelf Registration Statement ceases to be effective for any reason at
any time during the Effectiveness Period (other than because all Registrable
Securities registered thereunder shall have been resold pursuant thereto or
shall have otherwise ceased to be Registrable Securities, it being agreed that
the right of the Company to suspend the use of a Registration Statement pursuant
to Section 3(h) shall not be deemed a cessation of effectiveness of the
Registration Statement), the Company shall use its commercially reasonable
efforts to obtain the prompt withdrawal of any order suspending the
effectiveness thereof, and in any event shall within thirty (30) days of such
cessation of effectiveness amend the Shelf Registration Statement in a manner
reasonably expected to obtain the withdrawal of the order suspending the
effectiveness thereof, or file an additional Shelf Registration Statement
covering all of the securities that as of the date of such filing are
Registrable Securities (a "Subsequent Shelf Registration Statement"). If a
Subsequent Shelf Registration Statement is filed, the Company shall use its
commercially reasonable efforts to cause the Subsequent Shelf Registration
Statement to become effective as promptly as is practicable after such filing
and to keep such Registration Statement (or subsequent Shelf Registration
Statement) continuously effective until the end of the Effectiveness Period.

         (c) The Company shall supplement and amend the Shelf Registration
Statement if required by the rules, regulations or instructions applicable to
the registration form used by the Company for such Shelf Registration Statement,
if required by the Securities Act or as necessary to name a Notice Holder as a
selling securityholder pursuant to Section (d) below.






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         (d) Each Holder agrees that if such Holder wishes to sell Registrable
Securities pursuant to a Shelf Registration Statement and related Prospectus, it
will do so only in accordance with this Section 2(d) and Section 3(h) of this
Agreement. Following the date that the Initial Shelf Registration Statement is
declared effective, each Holder that is not a Notice Holder wishing to sell
Registrable Securities pursuant to a Shelf Registration Statement and related
Prospectus agrees to deliver a completed and executed Notice and Questionnaire
to the Company at least ten (10) Business Days prior to any intended
distribution of Registrable Securities under the Shelf Registration Statement.
From and after the date the Initial Shelf Registration Statement is declared
effective, the Company shall, as promptly as practicable after the date a Notice
and Questionnaire is delivered pursuant to Section 8(c), and in any event upon
the later of (x) thirty (30) days after such date or (y) thirty (30) days after
the expiration of any Deferral Period in effect when the Notice and
Questionnaire is delivered or put into effect within five (5) Business Days of
such delivery date:

             (i) if required by applicable law, file with the SEC a
         post-effective amendment to the Shelf Registration Statement or prepare
         and, if required by applicable law, file a supplement to the related
         Prospectus or a supplement or amendment to any document incorporated
         therein by reference or file any other required document so that the
         Holder delivering such Notice and Questionnaire is named as a selling
         securityholder in the Shelf Registration Statement and the related
         Prospectus in such a manner as to permit such Holder to deliver such
         Prospectus to purchasers of the Registrable Securities in accordance
         with applicable law and, if the Company shall file a post-effective
         amendment to the Shelf Registration Statement, use its commercially
         reasonable efforts to cause such post-effective amendment to be
         declared effective under the Securities Act as promptly as is
         practicable, but in any event by the date (the "Amendment Effectiveness
         Deadline Date") that is ninety (90) days after the date such
         post-effective amendment is required by this clause to be filed;
         provided that the Company shall not be required to file more than three
         (3) post-effective amendments or supplements (to the extent not related
         to any such post-effective amendments) to the Shelf Registration
         Statement pursuant to this clause (i);

             (ii) provide such Holder copies of any documents filed pursuant to
         Section 2(d)(i); and

             (iii) notify such Holder as promptly as practicable after the
         effectiveness under the Securities Act of any post-effective amendment
         filed pursuant to Section 2(d)(i);






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<PAGE>

provided, that if such Notice and Questionnaire is delivered during a Deferral
Period, the Company shall so inform the Holder delivering such Notice and
Questionnaire and shall take the actions set forth in clauses (i), (ii) and
(iii) above upon expiration of the Deferral Period in accordance with Section
3(h). Notwithstanding anything contained herein to the contrary, (i) the Company
shall be under no obligation to name any Holder that is not a Notice Holder as a
selling securityholder in any Registration Statement or related Prospectus and
(ii) the Amendment Effectiveness Deadline Date shall be extended by up to ten
(10) Business Days from the expiration of a Deferral Period (and the Company
shall incur no obligation to pay Liquidated Damages during such extension) if
such Deferral Period shall be in effect on the Amendment Effectiveness Deadline
Date.

         (e) The parties hereto agree that the Holders of Registrable Securities
will suffer damages, and that it would not be feasible to ascertain the extent
of such damages with precision, if, other than as permitted hereunder,

             (i) the Initial Shelf Registration Statement has not been filed on
         or prior to the Filing Deadline Date,

             (ii) the Initial Shelf Registration Statement has not been declared
         effective under the Securities Act on or prior to the Effectiveness
         Deadline Date,

             (iii) the Company has failed to perform its obligations set forth
         in Section 2(d)(i) within the time period required therein,

             (iv) any post-effective amendment to a Shelf Registration Statement
         filed pursuant to Section 2(d)(i) has not become effective under the
         Securities Act on or prior to the Amendment Effectiveness Deadline
         Date, or

             (v) the aggregate duration of Deferral Periods in any period
         exceeds the number of days permitted in respect of such period pursuant
         to Section 3(h) hereof.





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<PAGE>

Each event described in any of the foregoing clauses (i) through (v) is
individually referred to herein as an "Event." For purposes of this Agreement,
each Event set forth above shall begin and end on the dates set forth in the
table set forth below:

          Type of
           Event              Beginning                   Ending
         by Clause              Date                       Date
         ---------      --------------------     --------------------------
            (i)         Filing Deadline Date     the date the Initial Shelf
                                                 Registration Statement is filed

           (ii)         Effectiveness Deadline   the date the Initial Shelf
                        Date                     Registration Statement becomes
                                                 effective under the Securities
                                                 Act

           (iii)        the date by which the    the date the Company performs
                        Company is required to   its obligations set forth in
                        perform its obligations  Section 2(d)(i)
                        under Section 2(d)(i)

           (iv)         the Amendment            the date the applicable post-
                        Effectiveness Deadline   effective amendment to a Shelf
                        Date                     Registration Statement becomes
                                                 effective under the Securities
                                                 Act

            (v)         the date on which the    termination of the Deferral
                        aggregate duration of    Period that caused the limit on
                        Deferral Periods in any  the aggregate duration of
                        twelve-month period      Deferral Periods to be exceeded
                        exceeds the number of
                        days permitted by
                        Section 3(h)

         Commencing on (and including) any date that an Event has begun and
ending on (but excluding) the next date on which there are no Events that have
occurred and are continuing (a "Damages Accrual Period"), the Company shall pay,
as liquidated damages and not as a penalty, to Record Holders of Registrable
Securities an amount (the "Liquidated Damages Amount") accruing, for each day in
the Damages Accrual Period, (i) in respect of any Debenture, at a rate per annum
equal to (1) 0.25% of the aggregate principal amount of such Debenture to and
including the 90th day of such Damages Accrual Period and (2) 0.5% of the
aggregate principal amount of such Debenture from and after the 91st day of such
Damages Accrual Period and (ii) in respect of each share of Underlying Common
Stock that has been issued upon conversion of a Debenture at a rate per annum
equal to (1) 0.25% of the Conversion Price on such date to and including the
90th day of such Damages Accrual Period and (2) 0.5% of the Conversion Price on
such date from and after the 91st day of such Damages Accrual Period, as the
case may be; provided that in the case of a Damages Accrual Period that is in
effect solely as a result of an Event of the type described in clause (iii) or
(iv) of the preceding paragraph, such Liquidated Damages Amount shall be paid




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only to the Holders (as set forth in the succeeding paragraph) that have
delivered Notices and Questionnaires that caused the Company to incur the
obligations set forth in Section 2(d) the non-performance of which is the basis
of such Event. In calculating the Liquidated Damages Amount on any date on which
no Debentures are outstanding, the Conversion Price and the Liquidated Damages
Amount payable with respect to the shares of Common Stock that are Registrable
Securities shall be calculated as if the Debentures were still outstanding.
Notwithstanding the foregoing, no Liquidated Damages Amount shall accrue as to
any Registrable Security from and after the earlier of (x) the date such
security is no longer a Registrable Security and (y) expiration of the
Effectiveness Period. The rate of accrual of the Liquidated Damages Amount with
respect to any period shall not exceed the rate provided for in this paragraph
notwithstanding the occurrence of multiple concurrent Events.

         The Liquidated Damages Amount shall accrue from the first day of the
applicable Damages Accrual Period, and shall be payable on each Damages Payment
Date during the Damage Accrual Period (and on the Damages Payment Date next
succeeding the end of the Damages Accrual Period if the Damage Accrual Period
does not end on a Damages Payment Date) to the Record Holders of the Registrable
Securities entitled thereto; provided that any Liquidated Damages Amount accrued
with respect to any Debenture or portion thereof redeemed by the Company on a
redemption date or converted into Underlying Common Stock on a conversion date
prior to the Damages Payment Date, shall, in any such event, be paid instead to
the Holder who submitted such Debenture or portion thereof for redemption or
conversion on the applicable redemption date or conversion date, as the case may
be, on such date (or promptly following the conversion date, in the case of
conversion); provided further, that, in the case of an Event of the type
described in clause (iii) or (iv) of the first paragraph of this Section 2(e),
such Liquidated Damages Amount shall be paid only to the Holders entitled
thereto pursuant to such first paragraph by check mailed to the address set
forth in the Notice and Questionnaire delivered by such Holder. The Trustee
shall be entitled, on behalf of Record Holders of Debentures or Underlying
Common Stock, to seek any available remedy for the enforcement of this
Agreement, including for the payment of such Liquidated Damages Amount.
Notwithstanding the foregoing, the parties agree that the sole damages payable
for a violation of the terms of this Agreement with respect to which liquidated
damages are expressly provided shall be such liquidated damages. Nothing shall
preclude any Holder from pursuing or obtaining specific performance or other
equitable relief with respect to this Agreement.

         All of the Company's obligations set forth in this Section 2(e) to pay
any Liquidated Damages Amount that is outstanding with respect to any
Registrable Security at the time such security ceases to be a Registrable
Security shall survive until such time as all such obligations with respect to
such security have been satisfied in full (notwithstanding termination of this
Agreement pursuant to Section 8(k)).





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<PAGE>

         The parties hereto agree that the liquidated damages provided for in
this Section 2(e) constitute a reasonable estimate of the damages that may be
incurred by Holders of Registrable Securities by reason of the failure of the
Shelf Registration Statement to be filed or declared effective or available for
effecting resales of Registrable Securities in accordance with the provisions
hereof.

         Section 3. Registration Procedures. In connection with the registration
obligations of the Company under Section 2 hereof, during the Effectiveness
Period, the Company shall:

             (a) Prepare and file with the SEC a Registration Statement or
         Registration Statements on any appropriate form under the Securities
         Act available for the sale of the Registrable Securities by the Holders
         thereof in accordance with the intended method or methods of
         distribution thereof, and use its commercially reasonable efforts to
         cause each such Registration Statement to become effective and remain
         effective until the expiration of the Effectiveness Period; provided
         that before filing any Registration Statement or Prospectus or any
         amendments or supplements thereto with the SEC, furnish to the Initial
         Purchasers and the Special Counsel of such offering, if any, copies of
         all such documents proposed to be filed at least three (3) Business
         Days prior to the filing of such Registration Statement or amendment
         thereto or Prospectus or supplement thereto.

             (b) Subject to Section 3(h), prepare and file with the SEC such
         amendments and post-effective amendments to each Registration Statement
         as may be necessary to keep such Registration Statement continuously
         effective for the applicable period specified in Section 2(a); cause
         the related Prospectus to be supplemented by any required prospectus
         supplement, and as so supplemented to be filed pursuant to Rule 424 (or
         any similar provisions then in force) under the Securities Act; and use
         its commercially reasonable efforts to comply with the provisions of
         the Securities Act applicable to it with respect to the disposition by
         holders of Registrable Securities of all securities covered by such
         Registration Statement during the Effectiveness Period.

             (c) As promptly as practicable give notice to the Notice Holders,
         the Initial Purchasers and the Special Counsel, (i) when any
         Prospectus, prospectus supplement, Registration Statement or
         post-effective amendment to a Registration Statement has been filed
         with the SEC and, with respect to a Registration Statement or any





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         post-effective amendment, when the same has been declared effective,
         (ii) of any request, following the effectiveness of the Initial Shelf
         Registration Statement under the Securities Act, by the SEC or any
         other federal or state governmental authority for amendments or
         supplements to any Registration Statement or related Prospectus or for
         additional information, (iii) of the issuance by the SEC or any other
         federal or state governmental authority of any stop order suspending
         the effectiveness of any Registration Statement or the initiation or
         threatening of any proceedings for that purpose, (iv) of the receipt by
         the Company of any notification with respect to the suspension of the
         qualification or exemption from qualification of any of the Registrable
         Securities for sale in any jurisdiction or the initiation or
         threatening of any proceeding for such purpose, (v) of the occurrence
         of, but not the nature of or details concerning, a Material Event and
         (vi) of the determination by the Company that a post-effective
         amendment to a Registration Statement will be filed with the SEC, which
         notice may, at the discretion of the Company (or as required pursuant
         to Section 3(h)), state that it constitutes a Deferral Notice, in which
         event the provisions of Section 3(h) shall apply.

             (d) Use its commercially reasonable efforts to obtain the
         withdrawal of any order suspending the effectiveness of a Registration
         Statement or the lifting of any suspension of the qualification (or
         exemption from qualification) of any of the Registrable Securities for
         sale in any jurisdiction in which they have been qualified for sale, in
         either case as promptly as practicable, and provide prompt notice to
         each Notice Holder and the Initial Purchasers of the withdrawal of any
         such order.

             (e) As promptly as practicable furnish to each Notice Holder, the
         Special Counsel and the Initial Purchasers, upon request and without
         charge, at least one (1) conformed copy of the Registration Statement
         and any amendment thereto, including exhibits and all documents
         incorporated or deemed to be incorporated therein by reference.

             (f) During the Effectiveness Period, deliver to each Notice Holder,
         the Special Counsel, if any, and the Initial Purchasers, in connection
         with any sale of Registrable Securities pursuant to a Registration
         Statement, without charge, as many copies of the Prospectus or
         Prospectuses relating to such Registrable Securities (including each
         preliminary prospectus) and any amendment or supplement thereto as such
         Notice Holder may reasonably request; and the Company hereby consents
         (except during such periods that a Deferral Notice is outstanding and
         has not been revoked) to the use of such Prospectus or each amendment
         or supplement thereto by each Notice Holder in connection with any
         offering and sale of the Registrable Securities covered by such
         Prospectus or any amendment or supplement thereto in the manner set
         forth therein.







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<PAGE>

             (g) Prior to any public offering of the Registrable Securities
         pursuant to a Registration Statement, use its commercially reasonable
         efforts to register or qualify or cooperate with the Notice Holders and
         the Special Counsel in connection with the registration or
         qualification (or exemption from such registration or qualification) of
         such Registrable Securities for offer and sale under the securities or
         Blue Sky laws of such jurisdictions within the United States as any
         Notice Holder reasonably requests in writing (which request may be
         included in the Notice and Questionnaire); prior to any public offering
         of the Registrable Securities pursuant to the Shelf Registration
         Statement, use its commercially reasonable efforts to keep each such
         registration or qualification (or exemption therefrom) effective during
         the Effectiveness Period in connection with such Notice Holder's offer
         and sale of Registrable Securities pursuant to such registration or
         qualification (or exemption therefrom) and do any and all other acts or
         things reasonably necessary or advisable to enable the disposition in
         such jurisdictions of such Registrable Securities in the manner set
         forth in the relevant Registration Statement and the related
         Prospectus; provided that the Company will not be required to (i)
         qualify as a foreign corporation or as a dealer in securities in any
         jurisdiction where it would not otherwise be required to qualify but
         for this Agreement or (ii) take any action that would subject it to
         general service of process in suits or to taxation in any such
         jurisdiction where it is not then so subject.

             (h) Upon (A) the issuance by the SEC of a stop order suspending the
         effectiveness of the Shelf Registration Statement or the initiation of
         proceedings with respect to the Shelf Registration Statement under
         Section 8(d) or 8(e) of the Securities Act, (B) the occurrence of any
         event or the existence of any fact (a "Material Event") as a result of
         which in the reasonable opinion of the Company any Registration
         Statement shall contain any untrue statement of a material fact or omit
         to state any material fact required to be stated therein or necessary
         to make the statements therein not misleading, or any Prospectus shall
         contain any untrue statement of a material fact or omit to state any
         material fact required to be stated therein or necessary to make the
         statements therein, in the light of the circumstances under which they
         were made, not misleading, or (C) the occurrence or existence of any
         pending corporate development that, in the reasonable discretion of the
         Company, makes it appropriate to suspend the availability of the Shelf
         Registration Statement and the related Prospectus:






                                       12
<PAGE>

             (i) in the case of clause (B) above, subject to the next sentence,
         as promptly as practicable prepare and file, if necessary pursuant to
         applicable law, a post-effective amendment to such Registration
         Statement or a supplement to the related Prospectus or any document
         incorporated therein by reference or file any other required document
         that would be incorporated by reference into such Registration
         Statement and Prospectus so that such Registration Statement does not
         contain any untrue statement of a material fact or omit to state any
         material fact required to be stated therein or necessary to make the
         statements therein not misleading, and such Prospectus does not contain
         any untrue statement of a material fact or omit to state any material
         fact required to be stated therein or necessary to make the statements
         therein, in the light of the circumstances under which they were made,
         not misleading, as thereafter delivered to the purchasers of the
         Registrable Securities being sold thereunder, and, in the case of a
         post-effective amendment to a Registration Statement, subject to the
         next sentence, use its commercially reasonable efforts to cause it to
         be declared effective as promptly as is practicable, and

             (ii) give notice to the Notice Holders, and the Special Counsel, if
         any, that the availability of the Shelf Registration Statement is
         suspended (a "Deferral Notice") and, upon receipt of any Deferral
         Notice, each Notice Holder agrees not to sell any Registrable
         Securities pursuant to the Registration Statement until such Notice
         Holder's receipt of copies of the supplemented or amended Prospectus
         provided for in clause (i) above, or until it is advised in writing by
         the Company that the Prospectus may be used, and has received copies of
         any additional or supplemental filings that are incorporated or deemed
         incorporated by reference in such Prospectus.

The Company will use its commercially reasonable efforts to ensure that the use
of the Prospectus may be resumed (x) in the case of clause (A) above, as
promptly as is practicable, (y) in the case of clause (B) above, as soon as, in
the sole judgment of the Company, public disclosure of such Material Event would
not be prejudicial to or contrary to the interests of the Company or, if
necessary to avoid unreasonable burden or expense, as soon as practicable
thereafter and (z) in the case of clause (C) above, as soon as in the reasonable
discretion of the Company, such suspension is no longer appropriate. The Company
shall be entitled to exercise its right under this Section 3(h) to suspend the
availability of the Shelf Registration Statement or any Prospectus, without
incurring or accruing any obligation to pay liquidated damages pursuant to
Section 2(e), no more than, and any such period during which the availability of
the Registration Statement and any Prospectus is suspended (the "Deferral
Period") shall, without incurring any obligation to pay liquidated damages
pursuant to Section 2(e), not exceed, 90 days in any twelve (12) month period.






                                       13
<PAGE>

             (i) If requested in writing in connection with a disposition of
         Registrable Securities pursuant to a Registration Statement, make
         reasonably available for inspection during normal business hours by a
         representative for the Notice Holders of such Registrable Securities,
         any broker-dealers, attorneys and accountants retained by such Notice
         Holders, and any attorneys or other agents retained by a broker-dealer
         engaged by such Notice Holders, all relevant financial and other
         records and pertinent corporate documents and properties of the Company
         and its subsidiaries, and cause the appropriate officers, directors and
         employees of the Company and its subsidiaries to make reasonably
         available for inspection during normal business hours on reasonable
         notice all relevant information reasonably requested by such
         representative for the Notice Holders, or any such broker-dealers,
         attorneys or accountants in connection with such disposition, in each
         case as is customary for similar "due diligence" examinations; provided
         that such persons shall first agree in writing with the Company that
         any non-public information shall be kept confidential by such persons
         and shall be used solely for the purposes of exercising rights under
         this Agreement, unless (i) disclosure of such information is required
         by court or administrative order or is necessary to respond to
         inquiries of regulatory authorities, (ii) disclosure of such
         information is required by law (including any disclosure requirements
         pursuant to federal securities laws in connection with the filing of
         any Registration Statement or the use of any prospectus referred to in
         this Agreement), (iii) such information becomes generally available to
         the public other than as a result of a disclosure or failure to
         safeguard by any such person or (iv) such information becomes available
         to any such person from a source other than the Company and such source
         is not bound by a confidentiality agreement, and provided further, in
         the case of clauses (i) and (ii), that such persons shall give the
         Company reasonable notice of such requirement and reasonable
         opportunity, at its expense, to seek an order, decree or judgment
         protecting the confidentiality of such information, and provided
         further that the foregoing inspection and information gathering shall,
         to the greatest extent possible, be coordinated on behalf of all the
         Notice Holders and the other parties entitled thereto by Special
         Counsel and shall be exercisable no more than one time in any 180 day
         period. Any person legally compelled to disclose any such confidential
         information made available for inspection shall provide the Company
         with prompt prior written notice of such requirement so that the
         Company may seek a protective order or other appropriate remedy.

             (j) Comply with all applicable rules and regulations of the SEC and
         make generally available to its securityholders earning statements
         (which need not be audited) satisfying the provisions of Section 11(a)
         of the Securities Act and Rule 158 thereunder (or any similar rule





                                       14
<PAGE>

         promulgated under the Securities Act) for a 12-month period commencing
         on the first day of the first fiscal quarter of the Company commencing
         after the effective date of a Registration Statement, which statements
         shall be made available no later than 45 days after the end of the
         12-month period or 90 days if the 12-month period coincides with the
         fiscal year of the Company.

             (k) Cooperate with each Notice Holder to facilitate the timely
         preparation and delivery of certificates representing Registrable
         Securities sold or to be sold pursuant to a Registration Statement,
         which certificates shall not bear any restrictive legends, and cause
         such Registrable Securities to be in such denominations as are
         permitted by the Indenture and registered in such names as such Notice
         Holder may request in writing at least one (1) Business Day prior to
         any sale of such Registrable Securities.

             (l) Provide a CUSIP number for all Registrable Securities covered
         by each Registration Statement not later than the effective date of
         such Registration Statement and provide the Trustee and the transfer
         agent for the Common Stock with printed certificates for the
         Registrable Securities that are in a form eligible for deposit with The
         Depository Trust Company.

             (m) Cooperate and assist in any filings required to be made with
         the National Association of Securities Dealers, Inc.

             (n) Upon (i) the filing of the Initial Shelf Registration Statement
         and (ii) the effectiveness of the Initial Shelf Registration Statement,
         announce the same, in each case by release to two of Reuters Economic
         Services, Bloomberg Business News or Business Wire.

         Section 4. Holder's Obligations. Each Holder agrees, by acquisition of
the Registrable Securities, that no Holder shall be entitled to sell any of such
Registrable Securities pursuant to a Registration Statement or to receive a
Prospectus relating thereto, unless such Holder has furnished the Company with a
Notice and Questionnaire as required pursuant to Section 2(d) hereof (including
the information required to be included in such Notice and Questionnaire) and
the information set forth in the next sentence. Each Notice Holder agrees
promptly to furnish to the Company all information required to be disclosed in
order to make the information previously furnished to the Company by such Notice
Holder not misleading and any other information regarding such Notice Holder and
the distribution of such Registrable Securities as the Company may from time to
time reasonably request. Any sale of any Registrable Securities by any Holder
shall constitute a representation and warranty by such Holder that the




                                       15
<PAGE>

information relating to such Holder and its plan of distribution is as set forth
in the Prospectus delivered by such Holder in connection with such disposition,
that such Prospectus does not as of the time of such sale contain any untrue
statement of a material fact relating to or provided by such Holder or its plan
of distribution and that such Prospectus does not as of the time of such sale
omit to state any material fact relating to or provided by such Holder or its
plan of distribution necessary to make the statements in such Prospectus, in the
light of the circumstances under which they were made, not misleading.

         Section 5. Registration Expenses. The Company shall bear all fees and
expenses incurred in connection with the performance by the Company of its
obligations under Sections 2 and 3 of this Agreement whether or not any
Registration Statement is declared effective, except as otherwise noted below.
Such fees and expenses shall include, without limitation, (i) all registration
and filing fees (including, without limitation, fees and expenses (x) with
respect to filings required to be made with the National Association of
Securities Dealers, Inc. and (y) of compliance with federal and state securities
or Blue Sky laws (including, without limitation, reasonable fees and
disbursements of the Special Counsel not in excess of $5,000 in connection with
Blue Sky qualifications of the Registrable Securities under the laws of such
jurisdictions as Notice Holders of a majority of the Registrable Securities
being sold pursuant to a Registration Statement may designate), (ii) printing
expenses (including, without limitation, expenses of printing certificates for
Registrable Securities in a form eligible for deposit with The Depository Trust
Company), (iii) duplication expenses relating to copies of any Registration
Statement or Prospectus delivered to any Holders hereunder, (iv) fees and
disbursements of counsel for the Company in connection with the Shelf
Registration Statement, (v) fees and disbursements of Special Counsel in
connection with the Shelf Registration Statement of up to $25,000, (vi)
reasonable fees and disbursements of the Trustee and its counsel and of the
registrar and transfer agent for the Common Stock and (vii) any Securities Act
liability insurance obtained by the Company in its sole discretion. In addition,
the Company shall pay the internal expenses of the Company (including, without
limitation, all salaries and expenses of officers and employees performing legal
or accounting duties), the expense of any annual audit, the fees and expenses
incurred in connection with the listing by the Company of the Registrable
Securities on any securities exchange on which similar securities of the Company
are then listed and the fees and expenses of any person, including special
experts, retained by the Company. Notwithstanding the provisions of this Section
5, each selling Holder of Registrable Securities shall pay selling expenses,
including any underwriting discount and commissions, and all transfer taxes, to
the extent required by applicable law, and such selling Holder's registration
expenses, including the fees and disbursements of its counsel (other than the
fees and disbursements of Special Counsel paid by the Company as referred to
above) and other representatives.




                                       16
<PAGE>

         Section 6. Indemnification and Contribution.

         (a) Indemnification by the Company. The Company agrees to indemnify and
hold harmless each Notice Holder, each person, if any, who controls any Notice
Holder within the meaning of either Section 15 of the Securities Act or Section
20 of the Exchange Act, and each affiliate of any Notice Holder within the
meaning of Rule 405 under the Securities Act from and against any and all
losses, claims, damages and liabilities (including, without limitation, any
legal or other expenses reasonably incurred in connection with defending or
investigating any such action or claim) caused by any untrue statement or
alleged untrue statement of a material fact contained in any Registration
Statement or any amendment thereof, any preliminary prospectus or the Prospectus
(as amended or supplemented if the Company shall have furnished any amendments
or supplements thereto), caused by any omission or alleged omission to state
therein a material fact required to be stated therein or necessary to make the
statements therein not misleading, except that the Company shall not be liable
to indemnify any Holder insofar as such losses, claims, damages or liabilities
are (i) caused by any such untrue statement or omission or alleged untrue
statement or omission based upon information relating to any Holder furnished to
the Company in writing by such Holder expressly for use therein, (ii) based upon
a Holder's failure to provide the Company with a material fact relating to the
Holder which is required to be included in the Registration Statement or
necessary to make a statement in the Registration Statement not be misleading,
(iii) relate to sales of Registrable Securities by a Holder to the person
asserting any such losses, claims, damages or liabilities, if such person was
not sent or given a Prospectus by or on behalf of the Holder, if required by law
so to have been delivered, at or prior to the written confirmation of the sale
of the Registrable Securities to such person, and if the Prospectus (as so
amended or supplemented) would have cured the defect giving rise to such losses,
claims, damages or liabilities, unless such failure is the result of
noncompliance by the Company with Section 3(f) hereof or (iv) based upon the
Holder's use of a prospectus during a period when the Holder has been notified
that the use of the prospectus has been suspended.

         (b) Indemnification by Holders. Each Holder agrees severally and not
jointly to indemnify and hold harmless the Company and its directors, officers
and each person, if any, who controls the Company (within the meaning of either
Section 15 of the Securities Act or Section 20 of the Exchange Act) and any of
their affiliates or any other Holder or its affiliates, to the same extent as
the foregoing indemnity from the Company to such Holder, but only with reference
to (i) information relating to such Holder furnished to the Company in writing
by or on behalf of such Holder expressly for use in such Registration Statement
or Prospectus or amendment or supplement thereto, (ii) information relating to
the Holder which the Holder fails to provide in writing for use in the
Registration Statement or Prospectus resulting in an omission of a material fact





                                       17
<PAGE>

required to be stated therein or necessary to make the statements therein not
misleading, or in connection with a sale of Registrable Securities for which the
Holder would not be entitled to indemnification pursuant under Section 6(a)(iii)
or 6(a)(iv). In no event shall the liability of any Holder hereunder be greater
in amount than the dollar amount of the proceeds received by such Holder upon
the sale of the Registrable Securities pursuant to the Registration Statement
giving rise to such indemnification obligation.

         (c) Conduct of Indemnification Proceedings. In case any proceeding
(including any governmental investigation) shall be instituted involving any
person in respect of which indemnity may be sought pursuant to Section 6(a) or
6(b) hereof, such person (the "indemnified party") shall promptly notify the
person against whom such indemnity may be sought (the "indemnifying party") in
writing and the indemnifying party, upon request of the indemnified party, shall
retain counsel reasonably satisfactory to the indemnified party to represent the
indemnified party and any others the indemnifying party may designate in such
proceeding and shall pay the reasonable fees and disbursements of such counsel
related to such proceeding. In any such proceeding, any indemnified party shall
have the right to retain its own counsel, but the fees and expenses of such
counsel shall be at the expense of such indemnified party unless (i) the
indemnifying party and the indemnified party shall have mutually agreed to the
retention of such counsel or (ii) the named parties to any such proceeding
(including any impleaded parties) include both the indemnifying party and the
indemnified party and representation of both parties by the same counsel would
be inappropriate under applicable ethical legal standards due to actual or
potential differing interests between them. It is understood that the
indemnifying party shall not, in respect of the legal expenses of any
indemnified party in connection with any proceeding or related proceedings in
the same jurisdiction, be liable for the fees and expenses of more than one
separate firm (in addition to any local counsel) for all such indemnified
parties and that all such fees and expenses shall be reimbursed as they are
incurred. Such firm shall be reasonably acceptable to the Company and shall be
designated in writing by, in the case of parties indemnified pursuant to Section
6(a), the Holders of a majority (with Holders of Debentures deemed to be the
Holders, for purposes of determining such majority, of the number of shares of
Underlying Common Stock into which such Debentures are or would be convertible
as of the date on which such designation is made) of the Registrable Securities
covered by the Registration Statement held by Holders that are indemnified
parties pursuant to Section 6(a) and, in the case of parties indemnified
pursuant to Section 6(b), the Company. The indemnifying party shall not be
liable for any settlement of any proceeding effected without its written
consent, but if settled with such consent or if there be a final judgment for
the plaintiff, the indemnifying party agrees to indemnify the indemnified party
from and against any loss or liability by reason of such settlement or judgment
that is indemnifiable pursuant to Section 6(a) or 6(b), as the case may be.





                                       18
<PAGE>

Notwithstanding the foregoing sentence, if at any time an indemnified party
shall have requested in writing an indemnifying party to reimburse the
indemnified party for fees and expenses of counsel as contemplated by the second
and third sentences of this paragraph, the indemnifying party agrees that it
shall be liable for any settlement of any proceeding effected without its
written consent if (i) such settlement is entered into more than 45 days after
receipt by such indemnifying party of the aforesaid request (ii) such
indemnifying party shall have received notice of the terms of such settlement at
least 30 days prior to such settlement being entered into and (iii) such
indemnifying party shall not have reimbursed the indemnified party in accordance
with such request prior to the date of such settlement. No indemnifying party
shall, without the prior written consent of the indemnified party, effect any
settlement of any pending or threatened proceeding in respect of which any
indemnified party is or could have been a party and indemnity could have been
sought hereunder by such indemnified party, unless such settlement includes an
unconditional release of such indemnified party from all liability on claims
that are the subject matter of such proceeding.

         (d) Contribution. To the extent that the indemnification provided for
in Section 6(a) or 6(b) is unavailable to an indemnified party or insufficient
in respect of any losses, claims, damages or liabilities referred to therein,
then each indemnifying party under such paragraph, in lieu of indemnifying such
indemnified party thereunder, shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims, damages or
liabilities (i) in such proportion as is appropriate to reflect the relative
benefits received by the indemnifying party or parties on the one hand and the
indemnified party or parties on the other hand or (ii) if the allocation
provided by clause (i) above is not permitted by applicable law, in such
proportion as is appropriate to reflect not only the relative benefits referred
to in clause (i) above but also the relative fault of the indemnifying party or
parties on the one hand and of the indemnified party or parties on the other
hand in connection with the statements or omissions that resulted in such
losses, claims, damages or liabilities, as well as any other relevant equitable
considerations. The relative benefits received by the Company shall be deemed to
be equal to the total net proceeds from the initial placement pursuant to the
Purchase Agreement (before deducting expenses) of the Registrable Securities to
which such losses, claims, damages or liabilities relate. The relative benefits
received by any Holder shall be deemed to be equal to the value of receiving
Registrable Securities that are registered under the Securities Act. The
relative fault of the Holders on the one hand and the Company on the other hand
shall be determined by reference to, among other things, whether the untrue or
alleged untrue statement of a material fact or the omission or alleged omission
to state a material fact relates to information supplied by the Holders or by
the Company or the failure of such party to provide information, and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission. The Holders' respective
obligations to contribute pursuant to this Section 6 are several in proportion
to the respective number of Registrable Securities they have sold pursuant to a
Registration Statement, and not joint.




                                       19
<PAGE>

         The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 6(d) were determined by pro rata
allocation or by any other method of allocation that does not take into account
the equitable considerations referred to in the immediately preceding paragraph.
The amount paid or payable by an indemnified party as a result of the losses,
claims, damages or liabilities referred to in the immediately preceding
paragraph shall be deemed to include, subject to the limitations set forth
above, any legal or other expenses reasonably incurred by such indemnified party
in connection with investigating or defending any such action or claim.
Notwithstanding this Section 6, no indemnifying party that is a selling Holder
shall be required to contribute any amount in excess of the amount by which the
total price at which the Registrable Securities sold by it and distributed to
the public were offered to the public exceeds the amount of any damages that
such indemnifying party has otherwise been required to pay by reason of such
untrue or alleged untrue statement or omission or alleged omission. No person
guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of
the Securities Act) shall be entitled to contribution from any person who was
not guilty of such fraudulent misrepresentation.

         (e) The remedies provided for in this Section 6 are not exclusive and
shall not limit any rights or remedies which may otherwise be available to an
indemnified party at law or in equity, hereunder, under the Purchase Agreement
or otherwise.

         (f) The indemnity and contribution provisions contained in this Section
6 shall remain operative and in full force and effect regardless of (i) any
termination of this Agreement, (ii) any investigation made by or on behalf of
any Holder, any person controlling any Holder or any affiliate of any Holder or
by or on behalf of the Company, its officers or directors or any person
controlling the Company and (iii) the sale of any Registrable Securities by any
Holder.

         Section 7. Information Requirements. The Company covenants that, if at
any time before the end of the Effectiveness Period, the Company is not subject
to the reporting requirements of the Exchange Act, it will cooperate with any
Holder and take such further reasonable action as any Holder may reasonably
request in writing (including, without limitation, making such reasonable
representations as any such Holder may reasonably request), all to the extent
required from time to time to enable such Holder to sell Registrable Securities
without registration under the Securities Act within the limitation of the
exemptions provided by Rule 144 and Rule 144A under the Securities Act and
customarily taken in connection with sales pursuant to such exemptions. Upon the




                                       20
<PAGE>

written request of any Holder, the Company shall deliver to such Holder a
written statement as to whether it has complied with such filing requirements,
unless such a statement has been included in the Company's most recent report
filed pursuant to Section 13 or Section 15(d) of Exchange Act. Notwithstanding
the foregoing, nothing in this Section 7 shall be deemed to require the Company
to register any of its securities (other than the Common Stock) under any
section of the Exchange Act.

         Section 8. Miscellaneous.

         (a) No Conflicting Agreements. The Company is not, as of the date
hereof, a party to, nor shall it, on or after the date of this Agreement, enter
into, any agreement with respect to its securities that conflicts with the
rights granted to the Holders in this Agreement. The Company represents and
warrants that the rights granted to the Holders hereunder do not in any way
conflict with the rights granted to the holders of the Company's securities
under any other agreements except to the extent that a waiver has been obtained.

         (b) Amendments and Waivers. The provisions of this Agreement, including
the provisions of this sentence, may not be amended, modified or supplemented,
and waivers or consents to departures from the provisions hereof may not be
given, unless the Company has obtained the written consent of Holders of a
majority of the then outstanding Underlying Common Stock constituting
Registrable Securities (with Holders of Debentures deemed to be the Holders, for
purposes of this Section, of the number of outstanding shares of Underlying
Common Stock into which such Debentures are or would be convertible as of the
date on which such consent is requested). Notwithstanding the foregoing, a
waiver or consent to depart from the provisions hereof with respect to a matter
that relates exclusively to the rights of Holders whose securities are being
sold pursuant to a Registration Statement and that does not directly or
indirectly affect the rights of other Holders may be given by Holders of at
least a majority of the Registrable Securities being sold by such Holders
pursuant to such Registration Statement; provided that the provisions of this
sentence may not be amended, modified or supplemented except in accordance with
the provisions of the immediately preceding sentence. Notwithstanding the
foregoing two sentences, this Agreement may be amended by written agreement
signed by the Company and the Initial Purchasers, without the consent of the
Holders of Registrable Securities, to cure any ambiguity or to correct or
supplement any provision contained herein that may be defective or inconsistent
with any other provision contained herein, or to make such other provisions in
regard to matters or questions arising under this Agreement that shall not
adversely affect the interests of the Holders of Registrable Securities. Each
Holder of Registrable Securities outstanding at the time of any such amendment,
modification, supplement, waiver or consent or thereafter shall be bound by any
such amendment, modification, supplement, waiver or consent effected pursuant to
this Section 8(b), whether or not any notice, writing or marking indicating such
amendment, modification, supplement, waiver or consent appears on the
Registrable Securities or is delivered to such Holder.




                                       21
<PAGE>

         (c) Notices. All notices and other communications provided for or
permitted hereunder shall be made in writing by hand delivery, by telecopier, by
courier guaranteeing overnight delivery or by first-class mail, return receipt
requested, and shall be deemed given (i) when made, if made by hand delivery,
(ii) upon confirmation, if made by telecopier, (iii) one (1) Business Day after
being deposited with such courier, if made by overnight courier or (iv) on the
date indicated on the notice of receipt, if made by first-class mail, to the
parties as follows:

             (i)   if to a Holder, at the most current address given by such
         Holder to the Company in a Notice and Questionnaire or any amendment
         thereto;

             (ii)  if to the Company, to:

                   IMPAX Laboratories, Inc.
                   3735 Castor Avenue
                   Philadelphia, PA 19124
                   Attention: Mr. Barry R. Edwards
                              Chief Executive Officer
                   Telecopy No.: (215) 289-5932

                   and

                   Blank Rome LLP
                   One Logan Square
                   Philadelphia, PA 19103-6998
                   Attention: Ronald Fisher, Esquire
                   Telecopy No.: (215) 832-5479

             (iii) if to the Initial Purchasers, to:

                   Citigroup Global Markets Inc.
                   388 Greenwich Street
                   New York, New York  10013
                   Attention: General Counsel
                   Telecopy No.: (212) 816-7912

or to such other address as such person may have furnished to the other persons
identified in this Section 8(c) in writing in accordance herewith (which shall
be deemed given when received).





                                       22
<PAGE>

         (d) Approval of Holders. Whenever the consent or approval of Holders of
a specified percentage of Registrable Securities is required hereunder,
Registrable Securities held by the Company or its affiliates (as such term is
defined in Rule 405 under the Securities Act) (other than the Initial Purchasers
or subsequent Holders if such subsequent Holders are deemed to be such
affiliates solely by reason of their holdings of such Registrable Securities)
shall not be counted in determining whether such consent or approval was given
by the Holders of such required percentage.

         (e) Successors and Assigns. Any person who purchases any Registrable
Securities from the Initial Purchasers shall be deemed, for purposes of this
Agreement, to be an assignee of the Initial Purchasers. This Agreement shall
inure to the benefit of and be binding upon the successors and assigns of each
of the parties and shall inure to the benefit of and be binding upon each Holder
of any Registrable Securities, provided that nothing herein shall be deemed to
permit any assignment, transfer or other disposition of Registrable Securities
in violation of the terms of the Indenture. If any transferee of any Holder
shall acquire Registrable Securities, in any manner, whether by operation of law
or otherwise, such Registrable Securities shall be held subject to all of the
terms of this Agreement, and by taking and holding such Registrable Securities,
such person shall be conclusively deemed to have agreed to be bound by and to
perform all of the terms and provisions of this Agreement and such person shall
be entitled to receive the benefits hereof.

         (f) Counterparts. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be original and all of which taken together
shall constitute one and the same agreement.

         (g) Headings. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

         (h) Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

         (i) Severability. If any term provision, covenant or restriction of
this Agreement is held to be invalid, illegal, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions set forth herein
shall remain in full force and effect and shall in no way be affected, impaired
or invalidated thereby, and the parties hereto shall use their best efforts to
find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by such term, provision, covenant or
restriction, it being intended that all of the rights and privileges of the
parties shall be enforceable to the fullest extent permitted by law.




                                       23
<PAGE>

         (j) Entire Agreement. This Agreement is intended by the parties as a
final expression of their agreement and is intended to be a complete and
exclusive statement of the agreement and understanding of the parties hereto in
respect of the subject matter contained herein and the registration rights
granted by the Company with respect to the Registrable Securities. Except as
provided in the Purchase Agreement, there are no restrictions, promises,
warranties or undertakings, other than those set forth or referred to herein,
with respect to the registration rights granted by the Company with respect to
the Registrable Securities. This Agreement supersedes all prior agreements and
undertakings among the parties with respect to such registration rights. No
party hereto shall have any rights, duties or obligations other than those
specifically set forth in this Agreement.

         (k) Termination. This Agreement and the obligations of the parties
hereunder shall terminate upon the end of the Effectiveness Period, except for
any liabilities or obligations under Section 4, 5 or 6 hereof and the
obligations to make payments of and provide for the Liquidated Damages Amount
under Section 2(e) hereof to the extent such amount accrues prior to the end of
the Effectiveness Period, each of which shall remain in effect in accordance
with its terms.



















                                       24
<PAGE>



         IN WITNESS WHEREOF, the parties have executed and delivered this
Registration Rights Agreement as of the date first written above.

                                                  IMPAX LABORATORIES, INC.





                                                  By:    /s/ Barry R. Edwards
                                                  ------------------------------
                                                  Name:  Barry R. Edwards
                                                  Title: Chief Executive Officer




                               [Signature Follows]




















                                       25
<PAGE>





Confirmed and accepted as of
the date first above written:

CITIGROUP GLOBAL MARKETS INC.


Acting severally on behalf of themselves
   and the several Initial Purchasers
   named in Schedule I to the Purchase
   Agreement.


By: /s/ Henry Schwake
   --------------------------------------------
   Name:  Henry Schwake
   Title: Director