<PAGE>

                                                                     EXHIBIT 3.1

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                  SEPRACOR INC.

     Victor H. Woolley and Mark G. Borden, being the duly elected Vice
President, Finance and Secretary, respectively, of Sepracor Inc., a corporation
organized and existing under and by virtue of the laws of the State of Delaware,
do hereby certify as follows:

     1. The name of the corporation is Sepracor Inc. (hereinafter called the
"Corporation").

     The date of filing of its original Certificate of incorporation with the
Secretary of State was January 27, 1984.

     2. That by vote of the Board of Directors of the Corporation at a meeting
held on October 29, 1991, and in accordance with Section 245 of the General
Corporation Law of Delaware, the Board of Directors adopted a resolution setting
forth the proposed Restated Certificate of Incorporation of the Corporation.

     3. This Restated Certificate of Incorporation only restates and integrates
and does not further amend the Corporation's Restated Certificate of
Incorporation and there is no discrepancy between such provisions and the
provisions of this Restated Certificate of Incorporation.

     FIRST: The name of the corporation is Sepracor Inc. (hereinafter called the
"Corporation").

     SECOND: The registered office of the Corporation is Corporation Trust
Center, 1209 Orange Street, in the City of Wilmington, in the County of New
Castle, in the State of Delaware. The name of its registered agent at that
address is The Corporation Trust Company.

     THIRD: The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware.

     FOURTH: The aggregate number of shares which the Corporation shall have
authority to issue is 26,000,000 of which (i) 25,000,000 shares shall be Common
Stock, $0.10 par value per share ("Common Stock"), and (ii) 1,000,000 shares
shall be

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Preferred Stock, $1.00 par value per share ("Preferred Stock").

          A. PREFERRED STOCK

     Preferred Stock may be issued from time to time in one or more series, each
of such series to have such terms as stated or expressed herein and in the
resolution or resolutions providing for the issue of such series adopted by the
Board of Directors of the Corporation as hereinafter provided. Any shares of
Preferred Stock which may be redeemed, purchased or acquired by the Corporation
may be reissued except as otherwise provided by law. Different series of
Preferred Stock shall not be construed to constitute different classes of shares
for the purposes of voting by classes unless expressly provided.

     Authority is hereby expressly granted to the Board of Directors from time
to time to issue the Preferred Stock in one or more series, and in connection
with the creation of any such series, by resolution or resolutions providing for
the issue of the shares thereof, to determine and fix such voting powers, full
or limited, or no voting powers, and such designations, preferences and relative
participating, optional or other special rights, and qualifications, limitations
or restrictions thereof, including without limitation thereof, dividend rights,
conversion rights, redemption privileges and liquidation preferences, as shall
be stated and expressed in such resolutions, all to the full extent now or
hereafter permitted by the General Corporation Law of Delaware. Without limiting
the generality of the foregoing, the resolutions providing for issuance of any
series of Preferred Stock may provide that such series shall be superior or rank
equally or be junior to the Preferred Stock of any other series to the extent
permitted by law. Except as otherwise provided in this Restated Certificate of
Incorporation, no vote of the holders of the Preferred Stock or Common Stock
shall be a prerequisite to the designation or issuance of any shares of any
series of the Preferred Stock authorized by and complying with the conditions of
this Restated Certificate of Incorporation, the right to have such vote being
expressly waived by all present and future holders of the capital stock of the
Corporation."

          B. COMMON STOCK.

     1. General. The voting, dividend and liquidation rights of the holders of
the Common Stock are subject to and qualified by the rights of the holders of
the Preferred Stock.

     2. Voting. The holders of the Common stock are entitled to one vote for
each share held at all meetings of stockholders (and written actions in lieu of
meetings). There shall be no cumulative voting.

     3. Dividends. Dividends may be declared and paid on the Common Stock from
funds lawfully available therefor as and when determined by the Board of

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<PAGE>

Directors and subject to any preferential dividend rights of any then
outstanding Preferred Stock.

     4. Liquidation. Upon the dissolution or liquidation of the Corporation,
whether voluntary or involuntary, holders of Common Stock will be entitled to
receive all assets of the Corporation available for distribution to its
stockholders, subject to any preferential rights of any then outstanding
Preferred Stock.

     FIFTH: To the fullest extent permitted by the Delaware General Corporation
Law, as it exists or may be amended, a director of the Corporation shall be not
liable to the Corporation or its stockholders for monetary damages for breach of
fiduciary duty as a director.

     SIXTH: The election of directors need not be by written ballot unless the
by- laws so provide.

     SEVENTH: The Board of Directors of the Corporation is authorized and
empowered from time to time in its discretion to make, alter, amend or repeal
by-laws of the Corporation, except as such power may be restricted or limited by
the General Corporation Law of the State of Delaware.

     EIGHTH: Whenever any compromise or arrangement is proposed between this
Corporation and its creditors or any class of them and/or between this
Corporation and its stockholders or any class of them, any court of equitable
jurisdiction within the State of Delaware may, on the application in a summary
way of this Corporation or of any creditor or stockholder thereof or on the
application of any receiver or receivers appointed for this Corporation under
the provisions of Section 291 of Title 8 of the Delaware Code or on the
application of trustees in dissolution or of any receiver or receivers appointed
for this Corporation under the provisions of Section 279 of Title 8 of the
Delaware Code order a meeting of the creditors or class of creditors, and/or of
the stockholders or class of stockholders of this Corporation, as the case may
be, to be summoned in such manner as the said court directs. If a majority in
number representing three-fourths in value of the creditors or class of
creditors, and/or of the stockholders or class of stockholders of this
Corporation, as the case may be, agrees to any compromise or arrangement and to
any reorganization of this Corporation as consequence of such compromise or
arrangement, the said compromise or arrangement and the said reorganization
shall, if sanctioned by the court to which the said application has been made,
be binding on all the creditors or class of creditors, and/or on all the
stockholders or class of stockholders of this Corporation, as the case may be,
and also on this Corporation.

     NINTH: The Corporation reserves the right to amend, alter, change or repeal
any provision contained in this Certificate of Incorporation in the manner now
or hereafter prescribed by law, and all rights and powers conferred herein on

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<PAGE>

stockholders, directors and officers are subject to this reserved power.

     TENTH: This Article is inserted for the management of the business and for
the conduct of the affairs of the Corporation, and it is expressly provided that
it is intended to be in furtherance and not in limitation or exclusion of the
powers conferred by the statutes of the State of Delaware.

     1. Number of Directors. The number of directors which shall constitute the
whole Board of Directors shall be determined by resolution of a majority of the
Board of Directors, but in no event shall be less than three. The number of
directors may be decreased at any time and from time to time by a majority of
the directors then in office, but only to eliminate vacancies existing by reason
of the death, resignation, removal or expiration of the term of one or more
directors. The directors shall be elected at the annual meeting of stockholders
by such stockholders as have the right to vote on such election. Directors need
not be stockholders of the Corporation.

     2. Classes of Directors. The Board of Directors shall be and is divided
into three classes: Class I, Class II and Class III. No one class shall have
more than one director more than any other class. If a fraction is contained in
the quotient arrived at by dividing the authorized number of directors by three,
then, if such fraction is one-third, the extra director shall be a member of the
Class I and, if such fraction is two-thirds, one of the extra directors shall be
a member of Class I and the other extra director shall be a member of Class II,
unless otherwise provided for from time to time by resolution adopted by a
majority of the Board of Directors.

     3. Election of Directors. Elections of directors need not be by written
ballot except as and to the extent provided in the By-laws of the Corporation.

     4. Terms of Office. Each director shall serve for a term ending on the date
of the third annual meeting following the annual meeting at which such director
was elected; provided, however, that each initial director in Class I shall
serve for a term ending on the date of the annual meeting next following the end
of the Corporation's fiscal year ending December 31, 1993; each initial director
in Class II shall serve for a term ending on the date of the annual meeting next
following the end of the Corporation's fiscal year ending December 31, 1992; and
each initial director in Class III shall serve for a term ending on the date of
the annual meeting next following the end of the Corporation's fiscal year
ending December 31, 1991.

     5. Allocation of Directors Among Classes in the Event of Increases or
Decreases in the Number of Directors. In the event of any increase or decrease
in the authorized number of directors, (i) each director then serving as such
shall nevertheless continue as a director of the class of which he is a member
until the expiration of his current term or his prior death, retirement or
resignation and (ii) the newly created or eliminated directorships resulting
from such increase or decrease shall be apportioned by the Board of Directors
among the three classes of directors so

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as to ensure that no one class has more than one director more than any other
class. To the extent possible, consistent with the foregoing rule, any newly
created directorships shall be added to those classes whose terms of office are
to expire at the latest dates following such allocation, and any newly
eliminated directorships shall be subtracted from those classes whose terms of
office are to expire at the earliest dates following such allocation, unless
otherwise provided for from time to time by resolution adopted by a majority of
the directors then in office, although less than a quorum.

     6. Tenure. Notwithstanding any provisions to the contrary contained herein,
each director shall hold office until his successor is elected and qualified, or
until his earlier death, resignation or removal.

     7. Vacancies. Any vacancy in the Board of Directors, however occurring,
including a vacancy resulting from an enlargement of the Board, may be filled
only by vote of a majority of the directors then in office, although less than a
quorum, or by a sole remaining director. A director elected to fill a vacancy
shall be elected for the unexpired term of his predecessor in office, if
applicable, and a director chosen to fill a position resulting from an increase
in the number of directors shall hold office until the next election of the
class for which such director shall have been chosen and until his successor is
elected and qualified, or until his earlier death, resignation or removal.

     8. Quorum. A majority of the total number of the whole Board of Directors
shall constitute a quorum at all meetings of the Board of Directors. In the
event one or more of the directors shall be disqualified to vote at any meeting,
then the required quorum shall be reduced by one for each such director so
disqualified; provided, however, that in no case shall less than one-third (1/3)
of the number so fixed constitute a quorum. In the absence of a quorum at any
such meeting, a majority of the directors present may adjourn the meeting from
time to time without further notice other than announcement at the meeting,
until a quorum shall be present.

     9. Action at Meeting. At any meeting of the Board of Directors at which a
quorum is present, the vote of a majority of those present shall be sufficient
to take any action, unless a different vote is specified by law or the
Corporation's Restated Certificate of Incorporation or By-Laws.

     10. Removal. Any one or more or all of the directors may be removed, with
or without cause, by the holders of at least seventy- five percent (75%) of the
shares then entitled to vote at an election of directors.

     11. Stockholder Nominations and Introduction of Business, Etc. Advance
notice of stockholder nominations for election of directors and other business
to be brought by stockholders before a meeting of stockholders shall be given in
the

                                        5

<PAGE>

manner provided in the By-Laws of the Corporation.

     12. Amendments to Article. Notwithstanding any other provisions of law,
this Restated Certificate of Incorporation or the Corporation's Amended and
Restated By-Laws, and notwithstanding the fact that a lesser percentage may be
specified by law, the affirmative vote of the holders of at least seventy-five
percent (75%) of the votes which all the stockholders would be entitled to cast
at any annual election of directors or class of directors shall be required to
amend or repeal, or to adopt any provision inconsistent with, this Article
TENTH."

     ELEVENTH: Until the closing of a firm commitment, underwritten public
offering of the Corporation's Common Stock (a "Public Offering"), any action
required or permitted to be taken at any annual or special meeting of
stockholders of the Corporation may be taken without a meeting, without prior
notice and without a vote, if a consent in writing, setting forth the action so
taken, is signed by the holders of outstanding stock having not less than the
minimum number of votes that would be necessary to authorize or take such action
at a meeting at which all shares entitled to vote on such action were present
and voted. Prompt notice of the taking of corporate action without a meeting by
less than unanimous written consent shall be given to those stockholders who
have not consented in writing. Effective upon the closing of a Public Offering,
stockholders of the Corporation may not take any action by written consent in
lieu of a meeting. Notwithstanding any other provision of law, this Restated
Certificate of Incorporation or the Corporation's By-laws, as amended, and
notwithstanding the fact that a lesser percentage may be specified by law, the
affirmative vote of the holders of at least seventy-five percent (75%) of the
votes which all the stockholders would be entitled to cast at any annual
election of directors or class of directors shall be required to amend or
repeal, or to adopt any provision inconsistent with this Article ELEVENTH.

     TWELFTH: Special meetings of stockholders may be called at any time by the
President or by the Chairman of the Board of Directors. Business transacted at
any special meeting of stockholders shall be limited to matters relating to the
purpose or purposes stated in the notice of meeting. Notwithstanding any other
provision of law, this Restated Certificate of Incorporation or the
Corporation's Amended and Restated By-laws, and notwithstanding the fact that a
lesser percentage may be specified by law, the affirmative vote of the holders
of at least seventy-five percent (75%) of the votes which all stockholders would
be entitled to cast at any annual election of directors or class of directors
shall be required to amend or repeal, or to adopt any provision inconsistent
with this Article TWELFTH."

     THIRTEENTH: 1. Actions, Suits and Proceedings Other than by or in the Right
of the Corporation. The Corporation shall indemnify each person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative

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(other than an action by or in the right of the Corporation), by reason of the
fact that he is or was, or has agreed to become, a director or officer of the
Corporation, or is or was serving, or has agreed to serve, at the request of the
Corporation, as a director, officer or trustee of, or in a similar capacity
with, another corporation, partnership, joint venture, trust or other enterprise
(including any employee benefit plan) (all such persons being referred to
hereafter as an "Indemnitee"), or by reason of any action alleged to have been
taken or omitted in such capacity, against all expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by him or on his behalf in connection with such action, suit or
proceeding and any appeal therefrom, if he acted in good faith and in a manner
he reasonably believed to be in, or not opposed to, the best interests of the
Corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful. The termination of any
action, suit or proceeding by judgment, order, settlement, conviction or upon a
plea of nolo contendere or its equivalent, shall not, of itself, create a
presumption that the person did not act in good faith and in a manner which he
reasonably believed to be in, or not opposed to, the best interests of the
Corporation, and, with respect to any criminal action or proceeding, had
reasonable cause to believe that his conduct was unlawful. Notwithstanding
anything to the contrary in this Article, except as set forth in Section 6
below, the Corporation shall not indemnify an Indemnitee seeking indemnification
in connection with a proceeding (or part thereof) initiated by the Indemnitee
unless the initiation thereof was approved by the Board of Directors of the
Corporation.

     2. Actions or Suits by or in the Right of the Corporation. The Corporation
shall indemnify any Indemnitee who was or is a party or is threatened to be made
a party to any threatened, pending or completed action or suit by or in the
right of the Corporation to procure a judgment in its favor by reason of the
fact that he is or was, or has agreed to become, a director or officer of the
Corporation, or is or was serving, or has agreed to serve, at the request of the
Corporation, as a director, officer or trustee of, or in a similar capacity
with, another corporation, partnership, joint venture, trust or other enterprise
(including any employee benefit plan), or by reason of any action alleged to
have been taken or omitted in such capacity, against all expenses (including
attorneys' fees) and amounts paid in settlement actually and reasonably incurred
by him or on his behalf in connection with such action, suit or proceeding and
any appeal therefrom, if he acted in good faith and in a manner he reasonably
believed to be in, or not opposed to, the best interests of the Corporation,
except that no indemnification shall be made in respect of any claim, issue or
matter as to which such person shall have been adjudged to be liable to the
Corporation unless and only to the extent that the Court of Chancery of Delaware
or the court in which such action or suit was brought shall determine upon
application that, despite the adjudication of such liability but in view of all
the circumstances of the case, such person is fairly and reasonably entitled to
indemnity for such expenses (including attorneys' fees) which the Court of
Chancery of Delaware or such other court shall

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deem proper.

     3. Indemnification for Expenses of Successful Party. Notwithstanding the
other provisions of this Article, to the extent that an Indemnitee has been
successful, on the merits or otherwise, in defense of any action, suit or
proceeding referred to in Sections 1 and 2 of this Article, or in defense of any
claim, issue or matter therein, or on appeal from any such action, suit or
proceeding, he shall be indemnified against all expenses (including attorneys'
fees) actually and reasonably incurred by him or on his behalf in connection
therewith. Without limiting the foregoing, if any action, suit or proceeding is
disposed of, on the merits or otherwise (including a disposition without
prejudice), without (i) the disposition being adverse to the Indemnitee, (ii) an
adjudication that the Indemnitee was liable to the Corporation, (iii) a plea of
guilty or nolo contendere by the Indemnitee, (iv) an adjudication that the
Indemnitee did not act in good faith and in a manner he reasonably believed to
be in or not opposed to the best interests of the Corporation, and (v) with
respect to any criminal proceeding, an adjudication that the Indemnitee had
reasonable cause to believe his conduct was unlawful, the Indemnitee shall be
considered for the purposes hereof to have been wholly successful with respect
thereto.

     4. Notification and Defense of Claim. As a condition precedent to his right
to be indemnified, the Indemnitee must notify the Corporation in writing as soon
as practicable of any action, suit, proceeding or investigation involving him
for which indemnity will or could be sought. With respect to any action, suit,
proceeding or investigation of which the Corporation is so notified, the
Corporation will be entitled to participate therein at its own expense and/or to
assume the defense thereof at its own expense, with legal counsel reasonably
acceptable to the Indemnitee. After notice from the Corporation to the
Indemnitee of its election so to assume such defense, the Corporation shall not
be liable to the Indemnitee for any legal or other expenses subsequently
incurred by the Indemnitee in connection with such claim, other than as provided
below in this Section 4. The Indemnitee shall have the right to employ his own
counsel in connection with such claim, but the fees and expenses of such counsel
incurred after notice from the Corporation of its assumption of the defense
thereof shall be at the expense of the Indemnitee unless (i) the employment of
counsel by the Indemnitee has been authorized by the Corporation, (ii) counsel
to the Indemnitee shall have reasonably concluded that there may be a conflict
of interest or position on any significant issue between the Corporation and the
Indemnitee in the conduct of the defense of such action or (iii) the Corporation
shall not in fact have employed counsel to assume the defense of such action, in
each of which cases the fees and expenses of counsel for the Indemnitee shall be
at the expense of the Corporation, except as otherwise expressly provided by
this Article. The Corporation shall not be entitled, without the consent of the
Indemnitee, to assume the defense of any claim brought by or in the right of the
Corporation or as to which counsel for the Indemnitee shall have reasonably made
the conclusion provided for in clause (ii) above.

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     5. Advance of Expenses. Subject to the provisions of Section 6 below, in
the event that the Corporation does not assume the defense pursuant to Section 4
of this Article of any action, suit, proceeding or investigation of which the
Corporation receives notice under this Article, any expenses (including
attorneys' fees) incurred by an Indemnitee in defending a civil or criminal
action, suit, proceeding or investigation or any appeal therefrom shall be paid
by the Corporation in advance of the final disposition of such matter, provided,
however, that the payment of such expenses incurred by an Indemnitee in advance
of the final disposition of such matter shall be made only upon receipt of an
undertaking by or on behalf of the Indemnitee to repay all amounts so advanced
in the event that it shall ultimately be determined that the Indemnitee is not
entitled to be indemnified by the Corporation as authorized in this Article.
Such undertaking may be accepted without reference to the financial ability of
such person to make such repayment.

     6. Procedure for Indemnification. In order to obtain indemnification or
advancement of expenses pursuant to Section 1, 2, 3 or 5 of this Article, the
Indemnitee shall submit to the Corporation a written request, including in such
request such documentation and information as is reasonably available to the
Indemnitee and is reasonably necessary to determine whether and to what extent
the Indemnitee is entitled to indemnification or advancement of expenses. Any
such indemnification or advancement of expenses shall be made promptly, and in
any event within 60 days after receipt by the Corporation of the written request
of the Indemnitee, unless with respect to requests under Section 1, 2 or 5 the
Corporation determines, by clear and convincing evidence, within such 60-day
period that the Indemnitee did not meet the applicable standard of conduct set
forth in Section 1 or 2, as the case may be. Such determination shall be made in
each instance by (a) a majority vote of a quorum of the directors of the
Corporation consisting of persons who are not at that time parties to the
action, suit or proceeding in question ("disinterested directors"), (b) if no
such quorum is obtainable, a majority vote of a committee of two or more
disinterested directors, (c) a majority vote of a quorum of the outstanding
shares of stock of all classes entitled to vote for directors, voting as a
single class, which quorum shall consist of stockholders who are not at that
time parties to the action, suit or proceeding in question, (d) independent
legal counsel (who may be regular legal counsel to the Corporation), or (e) a
court of competent jurisdiction.

     7. Remedies. The right to indemnification or advances as granted by this
Article shall be enforceable by the Indemnitee in any court of competent
jurisdiction if the Corporation denies such request, in whole or in part, or if
no disposition thereof is made within the 60-day period referred to above in
Section 6. Unless otherwise provided by law, the burden of proving that the
Indemnitee is not entitled to indemnification or advancement of expenses under
this Article shall be on the Corporation. Neither the failure of the Corporation
to have made a determination prior to the commencement of such action that
indemnification is proper in the

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circumstances because the Indemnitee has met the applicable standard of conduct,
nor an actual determination by the Corporation pursuant to Section 6 that the
Indemnitee has not met such applicable standard of conduct, shall be a defense
to the action or create a presumption that the Indemnitee has not met the
applicable standard of conduct. The Indemnitee's expenses (including attorneys'
fees) incurred in connection with successfully establishing his right to
indemnification, in whole or in part, in any such proceeding shall also be
indemnified by the Corporation.

     8. Subsequent Amendment. No amendment, termination or repeal of this
Article or of the relevant provisions of the General Corporation Law of Delaware
or any other applicable laws shall affect or diminish in any way the rights of
any Indemnitee to indemnification under the provisions hereof with respect to
any action, suit, proceeding or investigation arising out of or relating to any
actions, transactions or facts occurring prior to the final adoption of such
amendment, termination or repeal.

     9. Other Rights. The indemnification and advancement of expenses provided
by this Article shall not be deemed exclusive of any other rights to which an
Indemnitee seeking indemnification or advancement of expenses may be entitled
under any law (common or statutory), agreement or vote of stockholders or
disinterested directors or otherwise, both as to action in his official capacity
and as to action in any other capacity while holding office for the Corporation,
and shall continue as to an Indemnitee who has ceased to be a director or
officer, and shall inure to the benefit of the estate, heirs, executors and
administrators of the Indemnitee. Nothing contained in this Article shall be
deemed to prohibit, and the Corporation is specifically authorized to enter
into, agreements with officers and directors providing indemnification rights
and procedures different from those set forth in this Article. In addition, the
Corporation may, to the extent authorized from time to time by its Board of
Directors, grant indemnification rights to other employees or agents of the
Corporation or other persons serving the Corporation and such rights may be
equivalent to, or greater or less than, those set forth in this Article.

     10. Partial Indemnification. If an Indemnitee is entitled under any
provision of this Article to indemnification by the Corporation for some or a
portion of the expenses (including attorneys' fees), judgments, fines or amounts
paid in settlement actually and reasonably incurred by him or on his behalf in
connection with any action, suit, proceeding or investigation and any appeal
therefrom but not, however, for the total amount thereof, the Corporation shall
nevertheless indemnify the Indemnitee for the portion of such expenses
(including attorneys' fees), judgments, fines or amounts paid in settlement to
which the Indemnitee is entitled.

     11. Insurance. The Corporation may purchase and maintain insurance, at its
expense, to protect itself and any director, officer, employee or agent of the

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Corporation or another corporation, partnership, joint venture, trust or other
enterprise (including any employee benefit plan) against any expense, liability
or loss incurred by him in any such capacity, or arising out of his status as
such, whether or not the Corporation would have the power to indemnify such
person against such expense, liability or loss under the General Corporation Law
of Delaware.

     12. Merger or Consolidation. If the Corporation is merged into or
consolidated with another corporation and the Corporation is not the surviving
corporation, the surviving corporation shall assume the obligations of the
Corporation under this Article with respect to any action, suit, proceeding or
investigation arising out of or relating to any actions, transactions or facts
occurring prior to the date of such merger or consolidation.

     13. Savings Clause. If this Article or any portion hereof shall be
invalidated on any ground by any court of competent jurisdiction, then the
Corporation shall nevertheless indemnify each Indemnitee as to any expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement in
connection with any action, suit, proceeding or investigation, whether civil,
criminal or administrative, including an action by or in the right of the
Corporation, to the fullest extent permitted by any applicable portion of this
Article that shall not have been invalidated and to the fullest extent permitted
by applicable law.

     14. Definitions. Terms used herein and defined in Section 145(h) and
Section 145(i) of the General Corporation Law of Delaware shall have the
respective meanings assigned to such terms in such Section 145(h) and Section
145(i).

     15. Subsequent Legislation. If the General Corporation Law of Delaware is
amended after adoption of this Article to expand further the indemnification
permitted to Indemnitees, then the Corporation shall indemnify such persons to
the fullest extent permitted by the General Corporation Law of Delaware, as so
amended.

     This Restated Certificate of Incorporation supersedes and takes the place
of the heretofore existing Restated Certificate of Incorporation of this
Corporation and any and all amendments, certificates and supplements thereto, if
any.

     IN WITNESS WHEREOF, said Sepracor Inc. has caused this Restated Certificate
of Incorporation to be signed by Victor H. Woolley, its Vice President, Finance,
and attested by Mark G. Borden, its Secretary, this 17th day of December, 1991.

                                             By: /s/ Victor H. Woolley
                                                 ---------------------
                                                 Victor H. Woolley
                                                 Vice President, Finance

ATTEST:

By: /s/ Mark G. Borden
    ------------------
    Mark G. Borden
    Secretary


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                       CERTIFICATE OF OWNERSHIP AND MERGER

                                     merging

                              IBF Biotechnics Inc.,
                             a Delaware corporation

                                      into

                                 Sepracor Inc.,
                             a Delaware corporation

     Sepracor Inc., a corporation organized and existing under the laws of the
State of Delaware (the "Corporation"), does hereby certify:

     FIRST: That the Corporation was incorporated on the 27th day of January,
1984, pursuant to the General Corporation Law of the State of Delaware.

     SECOND: That the Corporation owns all of the outstanding shares of the only
class of authorized capital stock of IBF Biotechnics Inc., a corporation
incorporated on December 8, 1986, pursuant to the General Corporation Law of the
State of Delaware.

     THIRD: That the Corporation, by the following resolutions of its Board of
Directors, duly adopted at a Meeting of the Board of Directors on November 24,
1992, determined to merge IBF Biotechnics Inc. into the Corporation:

RESOLVED:   That the Corporation, being the holder of 100% of the authorized and
            outstanding capital stock of IBF Biotechnics Inc., a Delaware
            corporation ("IBF"), hereby approves and authorizes the merger of
            IBF with and into the Company (the "IBF Merger") pursuant to Section
            253 of the Delaware General Corporation Law, such merger to be
            effective upon the filing of a Certificate of Ownership and Merger
            with the Secretary of State of Delaware, and that the Company hereby
            assumes all of the obligations of IBF which the Company is required
            to assume under Delaware law.

FURTHER
RESOLVED:   That the Restated Certificate of Incorporation of the Company, as
            amended, shall be the Certificate of Incorporation of the Company as
            of the effective date of the IBF Merger.

FURTHER
RESOLVED:   That the appropriate officers of the Company be, and each of


                                        1

<PAGE>

            them acting singly hereby is, authorized to execute all such
            documents and instruments as they or any of them deem necessary or
            appropriate to effectuate the purposes of the foregoing resolutions.

     IN WITNESS WHEREOF, Sepracor Inc. has caused this Certificate to be signed
by its President and attested by its Secretary, this 21st day of December, 1992.

                                         By: /s/ Timothy J. Barberich
                                             ------------------------
                                             Timothy J. Barberich,
                                             President

ATTEST:

By: /s/ Mark G. Borden
    ------------------
    Mark G. Borden
    Secretary

                                        2

<PAGE>

               Certificate of Designations of the Preferred Stock
                                       of
                                  Sepracor Inc.
                                To be Designated
                      Series A Convertible Preferred Stock


     Sepracor, Inc., a Delaware corporation (the "Corporation"), pursuant to
authority conferred on the Board of Directors of the Corporation by the
Certificate of Incorporation and in accordance with the provisions of Section
151 of the General Corporation law of the State of Delaware, certifies that the
Board of Directors of the Corporation, by unanimous written consent in lieu of a
meeting, duly adopted the following resolution:

     RESOLVED:   That, pursuant to the authority expressly granted to and vested
                 in the Board of Directors of the Corporation in accordance with
                 the provisions of its Certificate of Incorporation, a series of
                 Preferred Stock of the Corporation be and hereby is
                 established, consisting of 80,000 shares, to be designated
                 "Series A Convertible Preferred Stock" (hereinafter "Series A
                 Preferred Stock"); that the Board of Directors be and hereby is
                 authorized to issue such shares of Series A Preferred Stock
                 from time to time and for such consideration and on such terms
                 as the Board of Directors shall determine; and that, subject to
                 the limitations provided by law and by the Certificate of
                 Incorporation, the powers, designations, preferences and
                 relative, participating, optional or other special rights of,
                 and the qualifications, limitations or restrictions upon, the
                 Series A Preferred Stock shall be as follows:

                 Eighty Thousand (80,000) shares of the authorized and unissued
                 Preferred Stock of the Corporation ("Series Preferred Stock")
                 are hereby designated "Series A Convertible Preferred Stock"
                 (the "Series A Preferred Stock") with the following rights,
                 preferences, powers, privileges and restrictions,
                 qualifications and limitations.

     1. Dividends.

     (a) The Corporation shall not declare or pay any distributions (as defined
below) on shares of Common Stock until the holders of the Series A Preferred
Stock then outstanding shall have first received, or simultaneously receive, a
dividend on each


                                        1

<PAGE>

     (b) After the payment of all preferential amounts required to be paid to
the holders of Senior Preferred Stock, Series A Preferred Stock and any other
class or series of stock of the Corporation ranking on liquidation on a parity
with the Series A Preferred Stock, upon the dissolution, liquidation or winding
up of the Corporation, the holders of shares of Junior Stock then outstanding
shall be entitled to receive the remaining assets and funds of the Corporation
available for distribution to its stockholders.

     (c) In the event of any merger or consolidation of the Corporation into or
with another corporation (except one in which the holders of capital stock of
the Corporation immediately prior to such merger or consolidation continue to
hold at least 60% by voting power of the capital stock of the surviving
corporation), or the sale of all or substantially all of the assets of the
Corporation where the consideration payable to the holders of Series A Preferred
Stock (in the case of a merger or consolidation), or the consideration payable
to such holders, together with all other available assets of the Corporation (in
the case of an asset sale), is less than $63.00 per share of Series A Preferred
Stock, then, if the holders of at least a majority of the then outstanding
shares of Series A Preferred Stock so elect by giving written notice thereof to
the Corporation at least three days before the effective date of such event,
then such merger, consolidation or asset sale shall be deemed to be a
liquidation of the Corporation, and all consideration payable to the
stockholders of the Corporation (in the case of a merger or consolidation), or
all consideration payable to the Corporation, together with all other available
assets of the Corporation (in the case of an asset sale), shall be distributed
to the holders of capital stock of the Corporation in accordance with
Subsections 2(a) and 2(b) above. The Corporation shall promptly provide to the
holders of shares of Series A Preferred Stock such information concerning the
terms of such merger, consolidation or asset sale and the value of the assets of
the Corporation as may reasonably be requested by the holders of Series A
Preferred Stock in order to assist them in determining whether to make such an
election. The amount deemed distributed to the holders of Series A Preferred
Stock upon any such merger or consolidation shall be the cash or the value of
the property, rights or securities distributed to such holders by the acquiring
person, firm or other entity. The value of such property, rights or other
securities shall be reasonably determined by the Board of Directors of the
Corporation. If no notice of the election permitted by this Subsection (c) is
given, the provisions of Subsection 4(i) shall apply. Any other merger or
consolidation of the Corporation into or with another corporation shall not be
deemed to be a liquidation, dissolution, or winding up of the Corporation for
purposes of this Section 2.

     3. Voting.

     (a) Each holder of outstanding shares of Series A Preferred Stock shall be
entitled to the number of votes equal to the number of whole shares of Common
Stock into which the shares of Series A Preferred Stock held by such holder are
then

                                        2

<PAGE>

convertible (as adjusted form time to time pursuant to Section 4 hereof), at
each meeting of stockholders of the Corporation (and written actions of
stockholders in lieu of meetings) with respect to any and all matters presented
to the stockholders of the Corporation for their action or consideration. Except
as provided by law, or by the provisions establishing any other series of Series
Preferred Stock, holders of Series A Preferred Stock and of any other
outstanding series of Series Preferred Stock shall vote together with the
holders of Common Stock as a single class.

     (b) Without the consent of the holders of majority of the Series A
Preferred Stock, the Corporation shall not enter into any merger or
consolidation (except one in which the holders of capital stock of the
Corporation immediately prior to such merger or consolidation continue to hold
at least 60% by voting power of the capital stock of the surviving corporation)
or the sale of substantially all the assets of the Corporation where the
consideration payable to the holders of the Series A Preferred Stock shall have
a value less than $63.00 per share, in the same form as the consideration being
given to the majority of shares of Common Stock with the value being determined
by an independent appraiser.

     4. Optional Conversion. The holders of the Series A Preferred Stock shall
have conversion rights as follows (the "Conversion Rights"):

        (a) Right to Convert. Each share of Series A Preferred Stock shall be
convertible, at the option of the holder thereof, at any time and from time to
time, and without the payment of additional consideration by the holder thereof,
into such number of fully paid and nonassessable shares of Common Stock as is
determined by dividing $63.00 by the Conversion Price (as defined below) in
effect at the time of conversion. The "Conversion Price" shall initially be
$6.30. Such initial Conversion Price, and the rate at which shares of Series A
Preferred Stock may be converted into shares of Common Stock, shall be subject
to adjustment as provided below.

        (b) Fractional Shares. No fractional shares of Common Stock shall be
issued upon conversion of the Series A Preferred Stock. In lieu of any
fractional shares to which the holder would otherwise be entitled, the
Corporation shall pay cash equal to such fraction multiplied by the then fair
market value of the Common Stock.

        (c) Mechanics of Conversion.

            (i) In order for a holder of Series A Preferred Stock to convert
shares of Series A Preferred Stock into shares of Common Stock, such holder
shall surrender the certificate or certificates for such shares of Series A
Preferred Stock, at the office of the transfer agent for the Series A Preferred
Stock (or at the principal office of the Corporation if the Corporation serves
as its own transfer agent), together with written notice that such holder elects
to convert all or any number of the shares

                                        3

<PAGE>

of the Series A Preferred Stock represented by such certificate or certificates.
Such notice shall state such holder's name or the names of the nominees in which
such holder wishes the certificate or certificates for shares of Common Stock to
be issued. If required by the Corporation, certificates surrendered for
conversion shall be endorsed or accompanied by a written instrument or
instruments of transfer, in form satisfactory to the Corporation, duly executed
by the registered holder or his or its attorney duly authorized in writing. The
date of receipt of such certificates and notice by the transfer agent (or by the
Corporation if the Corporation serves as its own transfer agent) shall be the
conversion date ("Conversion Date"). The Corporation shall, as soon as
practicable after the Conversion Date, issue and deliver at such office to such
holder of Series A Preferred Stock, or to his or its nominees, a certificate or
certificates for the number of shares of Common Stock to which such holder shall
be entitled, together with cash in lieu of any fraction of a share.

            (ii) The Corporation shall at all times when the Series A Preferred
Stock shall be outstanding, reserve and keep available out of its authorized but
unissued stock, for the purpose of effecting the conversion of the Series A
Preferred Stock, such number of its duly authorized shares of Common Stock as
shall from time to time be sufficient to effect the conversion of all
outstanding Series A Preferred Stock. Before taking any action which would cause
an adjustment reducing the Conversion Price below the then par value of the
shares of Common Stock issuable upon conversion of the Series A Preferred Stock,
the Corporation will take any corporate action which may, in the opinion of its
counsel, be necessary in order that the Corporation may validly and legally
issue fully paid and nonassessable shares of Common Stock at such adjusted
Conversion Price.

            (iii) Upon any such conversion, no adjustment of the Conversion
Price shall be made for any declared or accrued but unpaid dividends on the
Series A Preferred Stock surrendered for conversion or on the Common Stock
delivered upon conversion.

            (iv) All shares of Series A Preferred Stock which shall have been
surrendered for conversion as herein provided shall no longer be deemed to be
outstanding and all rights with respect to such shares, including the rights, if
any, to receive notices and to vote, shall immediately cease and terminate on
the Conversion Date, except only the right of the holders thereof to receive
shares of Common Stock in exchange therefor and payment of any dividends
declared but unpaid thereon. Any shares of Series A Preferred Stock so converted
shall be retired and cancelled and shall not be reissued, and the Corporation
(without the need for stockholder action) may from time to time take such
appropriate action as may be necessary to reduce the authorized Series A
Preferred Stock accordingly.

            (v) The Corporation shall pay any and all issue and other taxes that
may be payable in respect of any issuance or delivery of shares of

                                        4

<PAGE>

Common Stock upon conversion of shares of Series A Preferred Stock pursuant to
this Section 4. The Corporation shall not, however, be required to pay any tax
which may be payable in respect of any transfer involved in the issuance and
delivery of shares of Common Stock in a name other than that in which the shares
of Series A Preferred Stock so converted were registered, and no such issuance
or delivery shall be made unless and until the person or entity requesting such
issuance has paid to the Corporation the amount of any such tax or has
established, to the satisfaction of the Corporation, that such tax has been
paid.

        (d) Adjustments to Conversion Price for Diluting Issues:

            (i) Special Definitions. For purposes of this Subsection 4(d), the
following definitions shall apply:

                (A) "Option" shall mean rights, options or warrants to subscribe
for, purchase or otherwise acquire Common Stock or Convertible Securities,
excluding options described in subsection 4(d)(i)(D)(V) below.

                (B) "Original Issue Price" shall mean the date on which a share
of Series A Preferred Stock was first issued.

                (C) "Convertible Securities" shall mean any evidences of
indebtedness, shares or other securities directly or indirectly convertible into
or exchangeable for Common Stock.

                (D) "Additional Shares of Common Stock" shall mean all shares of
Common Stock issued (or, pursuant to Subsection 4(d)(iii) below, deemed to be
issued) by the Corporation after the Original Issue Date, other than shares
issued or issuable:

                (E) "Common Stock" shall be deemed to include equity security
having rights to receive dividends or distributions (including liquidation) not
limited to a fixed sum or percentage of the purchase price therefor. The price
at which such securities are deemed issued for purposes of this Section 4(d)
shall take into account as appropriate the relationship between the terms
thereof and the terms of the Series A Preferred Stock.

                (I)   upon exercise of any warrants or options or conversion of
                      any convertible securities of the Corporation outstanding
                      prior to the Original Issuance Date;

                (II)  as a dividend or distribution on Series A Preferred Stock;

                (III) (by reason of a dividend, stock split, split-up

                                        5

<PAGE>

                      or other distribution on shares of Common Stock that is
                      covered by Subsection 4(e) or 4(f) below;

                (IV)  in connection with the acquisition by the Corporation of
                      another corporation of business;

                (V)   to employees or directors of, or consultants to, the
                      Corporation or any subsidiary as approved by the Board of
                      Directors of the Corporation, or

                (VI)  to pharmaceutical companies or other strategic partners in
                      connection with a licensing, development, joint venture or
                      similar arrangement between the Corporation and such
                      company or partner.

            (ii) No Adjustment of Conversion Price. No adjustment in the number
of shares of Common Stock into which the Series A Preferred Stock is convertible
shall be made, by adjustment in the applicable Conversion Price thereof: (a)
unless the consideration per share (determined pursuant to Subsection 4(d)(v))
for an Additional Share of Common Stock issued or deemed to be issued by the
Corporation is less than the applicable Conversion Price in effect on the date
of, and immediately prior to, the issue of such Additional Shares, or (b) if
prior to such issuance, the Corporation receives written notice from the holders
of at least a majority of the then outstanding shares of Series A Preferred
Stock agreeing that no such adjustment shall be made as the result of the
issuance of Additional Shares of Common Stock.

            (iii) Issue of Securities Deemed Issue of Additional Shares of
Common Stock. If the Corporation at any time or from time to time after the
Original Issue Date shall issue any Options or Convertible Securities or shall
fix a record date for the determination of holders of any class of securities
entitled to receive any such Options or Convertible Securities, then the maximum
number of shares of Common Stock (as set forth in the instrument relating
thereto without regard to any provision contained therein for a subsequent
adjustment of such number) issuable upon the exercise of such Options or, in the
case of Convertible Securities and Options therefor, the conversion or exchange
of such Convertible Securities, shall be deemed to be Additional Shares of
Common Stock issued as of the time of such issue or, in case such a record date
shall have been fixed, as of the close of business on such record date, provided
that Additional Shares of Common Stock shall not be deemed to have been issued
unless the consideration per share (determined pursuant to Subsection 4(d)(v)
hereof) of such Additional Shares of Common Stock would be less than the
applicable Conversion Price in effect on the date of and immediately prior to
such issue, or such record date, as the case may be, and provided further that
in any

                                        6

<PAGE>

such case in which Additional Shares of Common Stock are deemed to be issued:

                (A) No further adjustment in the Conversion Price shall be made
upon the subsequent issue of Convertible Securities or shares of Common Stock
upon the exercise of such Options or conversion or exchange of such Convertible
Securities;

                (B) If such Options or Convertible Securities by their terms
provide, with the passage of time or otherwise, for any increase or decrease in
the consideration payable to the Corporation, upon the exercise, conversion or
exchange thereof, the Conversion Price computed upon the original issue thereof
(or upon the occurrence of a record date with respect thereto), and any
subsequent adjustments based thereon, shall, upon any such increase or decrease
becoming effective, be recomputed to reflect such increase or decrease, as
applicable, insofar as it affects such Options or the rights or conversion or
exchange under such Convertible Securities;

                (C) Upon the expiration or termination of any unexercised
Option, the Conversion Price shall not be readjusted; and

                (D) No readjustment pursuant to clause (B) above shall have the
effect of increasing the Conversion Price to an amount which exceeds the lower
of (i) the Conversion Price on the original adjustment date, or (ii) the
Conversion Price that would have resulted from any issuances of Additional
Shares of Common Stock between the original adjustment date and such
readjustment date.

            (iv) Adjustment of Conversion Price Upon Issuance of Additional
Shares of Common Stock. In the event the Corporation shall at any time after the
Original Issue Date issue Additional Shares of Common Stock (including
Additional Shares of Common Stock deemed to be issued pursuant to Subsection
4(d)(iii), but excluding shares issued as a dividend or distribution as provided
in Subsection 4(f) or upon a stock split or combination as provided in
Subsection 4(e)), without consideration or for a consideration per share less
than the applicable Conversion Price in effect on the date of and immediately
prior to such issue, then and in such event, such Conversion Price shall be
reduced, concurrently with such issue, to a price equal to the consideration per
share received by the Corporation for the issue of the Additional Shares of
Common Stock (determined pursuant to Subsection 4(d)(v)).

            (v) Determination of Consideration. For purposes of this Subsection
4(d), the consideration received by the Corporation for the issue of any
Additional Shares of Common Stock shall be computed as follows:

                (A) Cash and Property: Such consideration shall:


                                        7

<PAGE>

                (I)   insofar as it consists of cash, be computed at the
                      aggregate of cash received by the Corporation, excluding
                      amounts paid or payable for accrued interest or accrued
                      dividends;

                (II)  insofar as it consists of property other than cash, be
                      computed at the fair market value thereof at the time of
                      such issue, as reasonably determined by the Board of
                      Directors, and

                (III) in the event Additional Shares of Common Stock are issued
                      together with other shares or securities or other assets
                      of the Corporation for consideration which covers both, be
                      the proportion of such consideration so received, computed
                      as provided in clauses (I) and (II) above, as reasonably
                      determined by the Board of Directors.

                (B) Options and Convertible Securities. The consideration per
share received by the Corporation for Additional Shares of Common Stock deemed
to have been issued pursuant to Subsection 4(d)(iii), relating to Options and
Convertible Securities, shall be determined by dividing

                    (x) the total amount, if any, received or receivable by the
Corporation as consideration for the issue of such Options or Convertible
Securities, plus the minimum aggregate amount of additional consideration (as
set forth in the instruments relating thereto, without regard to any provision
contained therein for a subsequent adjustment of such consideration) payable to
the Corporation upon the exercise of such Options or the conversion or exchange
of such Convertible Securities, or in the case of Options for Convertible
Securities, the exercise of such Options for Convertible Securities and the
conversion or exchange of such Convertible Securities, by

                    (y) the maximum number of shares of Common Stock (as set
forth in the instruments relating thereto, without regard to any provision
contained therein for a subsequent adjustment of such number) issuable upon the
exercise of such Options or the conversion or exchange of such Convertible
Securities.

     (e) Adjustment for Stock Splits and Combinations. If the Corporation shall
at any time or from time to time after the Original Issue Date effect a
subdivision of the outstanding Common Stock, the Conversion Price then in effect
immediately before that subdivision shall be proportionately decreased. If the
Corporation shall at any time or from time to time after the Original Issue Date
effect

                                        8

<PAGE>

a subdivision of the Series A Preferred Stock, the Conversion Price then in
effect immediately before that subdivision shall be proportionately increased.
If the Corporation shall at any time or from time to time after the Original
Issue Date combine the outstanding shares of Common Stock, the Conversion Price
then in effect immediately before the combination shall be proportionately
increased. If the Corporation shall at any time or from time to time after the
Original Issue Date combine the outstanding shares of Series A Preferred Stock,
the Conversion Price then in effect immediately before the combination shall be
proportionately decreased. Any adjustment under this paragraph shall become
effective at the close of business on the date the subdivision or combination
becomes effective.

     (f) Adjustment for Certain Dividends and Distributions. In the event the
Corporation at any time, or from time to time after the Original Issue Date
shall make or issue, or fix a record date for the determination of holders of
Common Stock entitled to receive, a dividend or other distribution payable in
additional shares of Common Stock, then and in each such event the Conversion
Price for the Series A Preferred Stock then in effect shall be decreased as of
the time of such issuance or, in the event such a record date shall have been
fixed, as of the close of business on such record date, by multiplying the
Conversion Price for the Series A Preferred Stock then in effect by a fraction:

         (1) the numerator of which shall be the total number of shares of
     Common Stock issued and outstanding immediately prior to the time of such
     issuance or the close of business on such record date, and

         (2) the denominator of which shall be the total number of shares of
     Common Stock issued and outstanding immediately prior to the time of such
     issuance or the close of business on such record date plus the number of
     shares of Common Stock issuable in payment of such dividend or
     distribution; provided, however, if such record date shall have been fixed
     and such dividend is not fully paid or if such distribution is not fully
     made on the date fixed therefore, the Conversion Price for the Series A
     Preferred Stock shall be recomputed accordingly as of the close of business
     on such record date and thereafter the Conversion Price for the Series A
     Preferred Stock shall be adjusted pursuant to this paragraph as of the time
     of actual payment of such dividends or distributions; and provided further,
     however, that no such adjustment shall be made if the holders of Series A
     Preferred Stock simultaneously receive a dividend or other distribution of
     shares of Common Stock in a number equal to the number of shares of Common
     Stock as they would have received if all outstanding shares of Series A
     Preferred Stock had been converted into Common Stock on the date of such
     event.

                                        9

<PAGE>

     (g) Prohibition on Certain Dividends and Distributions. The Corporation
shall not, at any time or from time to time after the Original Issue Date for
the Series A Preferred Stock, make or issue, or fix a record date for the
determination of holders of Common Stock entitled to receive, a dividend or
other distribution payable in securities of the Corporation other than shares of
Common Stock, unless the holders of Series A Preferred Stock simultaneously
receive a dividend or other distribution of such securities in an amount equal
to the amount of such securities as they would have received if all outstanding
shares of Series A Preferred Stock had been converted into Common Stock on the
date of such event.

     (h) Adjustment for Reclassification, Exchange or Substitution. If the
Common Stock issuable upon the conversion of the Series A Preferred Stock shall
be changed into the same or a different number of shares of any class or classes
of stock, whether by capital reorganization, reclassification, or otherwise
(other than a subdivision or combination of shares or stock dividend provided
for above, or a reorganization, merger, consolidation, or sale of assets
provided for below), then and in each such event the holder of each such share
of Series A Preferred Stock shall have the right thereafter to convert such
share into the kind and amount of shares of stock and other securities and
property receivable upon such reorganization, reclassification, or other change,
by holders of the number of shares of Common Stock into which such shares of
Series A Preferred Stock might have been converted immediately prior to such
reorganization, reclassification, or change, all subject to further adjustment
as provided herein.

     (i) Adjustment for Merger or Reorganization, etc. In case of any
consolidation or merger of the Corporation with or into another corporation or
the sale of all or substantially all of the assets of the Corporation to another
corporation, each share of Series A Preferred Stock shall thereafter be
convertible (or shall be converted into a security which shall be convertible)
into the kind and amount of shares of stock or other securities or property to
which a holder of the number of shares of Common Stock of the Corporation
deliverable upon conversion of such Series A Preferred Stock would have been
entitled upon such consolidation, merger or sale; and, in such case, appropriate
adjustment (as reasonably determined by the Board of Directors) shall be made in
the application of the provisions in this Section 4 set forth with respect to
the rights and interest thereafter of the holders of the Series A Preferred
Stock, to the end that the provisions set forth in this Section 4 (including
provisions with respect to changes in and other adjustments of the Conversion
Price) shall thereafter be applicable, as nearly as reasonably may be, in
relation to any shares of stock or other property thereafter deliverable upon
the conversion of the Series A Preferred Stock.

     (j) No Impairment. The Corporation will not, by amendment of its
Certificate of Incorporation or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities or any other
voluntary

                                       10

<PAGE>

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 of this Section 4
and in the taking of all such action as may be necessary or appropriate in order
to protect the Conversion Rights of the holders of the Series A Preferred Stock
against impairment. If any event occurs as to which the provisions of this
Section 4 are not applicable or if applicable would not fairly protect the
rights of the holders of Series A Preferred Stock in accordance with the
essential intent and principles of such provisions, the application of such
provisions will be adjusted in accordance with such essential intent and
principles so as to protect such rights, but in no event shall the Conversion
Price be increased.

     (k) Certificate as to Adjustments. Upon the occurrence of each adjustment
or readjustment of the Conversion Price pursuant to this Section 4, the
Corporation at its expense shall promptly compute such adjustment or
readjustment in accordance with the terms hereof and furnish to each holder 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 similar certificate setting forth (i) such adjustments and
readjustments, (ii) the Conversion Price then in effect, and (iii) the number of
shares of Common Stock and the amount, if any, of other property which then
would be received upon the conversion of Series A Preferred Stock.

     (l) Notice of Record Date. In the event:

         (i)   that the Corporation declares a dividend (or any other
               distribution) on its Common Stock payable in Common Stock or
               other securities of the Corporation;

         (ii)  that the Corporation subdivides or combines its outstanding
               shares of Common Stock;

         (iii) of any reclassification of the Common Stock of the Corporation
               (other than a subdivision or combination of its outstanding
               shares of Common Stock or a stock dividend or stock distribution
               thereon), or of any consolidation or merger of the Corporation
               into or with another corporation, or of the sale of all or
               substantially all of the assets of the Corporation; or

         (iv)  of the involuntary or voluntary dissolution, liquidation or
               winding upon of the Corporation; then the Corporation

                                       11

<PAGE>

               shall cause to be filed at its principal office or at the office
               of the transfer agent of the Series A Preferred Stock, and shall
               cause to be mailed to the holders of the Series A Preferred Stock
               at their last addresses as shown on the records of the
               Corporation or such transfer agent, at least ten days prior to
               the date specified in (A) below or twenty days before the date
               specified in (B) below, a notice stating

               (A) the record date of such dividend, distribution, subdivision
                   or combination, or, if a record is not to be taken, the date
                   as of which the holders of Common Stock of record to be
                   entitled to such dividend, distribution, subdivision or
                   combination are to be determined, or

               (B) the date on which such reclassification, consolidation,
                   merger, sale, dissolution, liquidation or winding up is
                   expected to become effective, and the date as of which it is
                   expected that holders of Common Stock of record shall be
                   entitled to exchange their shares of Common Stock for
                   securities or other property deliverable upon such
                   reclassification, consolidation, merger, sale, dissolution or
                   winding up.

     5. Mandatory Conversion.

     (a) All outstanding shares of Series A Preferred Stock shall automatically
be converted into shares of Common Stock, at the then effective conversion rate,
upon the earlier of (i) September 30, 2004 or (ii) upon written notice by the
Corporation to the holders of Series A Preferred Stock (which notice may not be
delivered prior to September 30, 1995) following a period of twenty (20)
consecutive trading days in which the lst reported sales price of the Common
Stock on the Nasdaq National Market (or a national securities exchange) equals
or exceeds 160% of the then effective Conversion Price (the "Mandatory
Conversion Date").

     (b) All holders of record of shares of Series A Preferred Stock will be
given written notice of the Mandatory Conversion Date and the place designated
for mandatory conversion of all such shares of Series A Preferred Stock pursuant
to this Section 5. Such notice shall be sent by first class or registered mail,
postage prepaid, to each record holder of Series A Preferred Stock at such
holder's address last shown on the records of the transfer agent for the Series
A Preferred Stock (or the records of the Corporation, if it serves as its own
transfer agent). Upon receipt of such notice, each holder of shares of Series A
Preferred Stock shall surrender his or its certificate or certificates for all
such shares to the Corporation at the place designated in such notice, and shall
thereafter receive certificates for the number of shares of Common Stock to
which such holder is entitled pursuant to this Section 5. On the Mandatory

                                       12

<PAGE>

Conversion Date, all rights with respect to the Series A Preferred Stock so
converted, including the rights, if any, to receive notices and vote, will
terminate, except only the rights of the holders thereof, upon surrender of
their certificate or certificates therefor, to receive certificates for the
number of shares of Common Stock into which such Series A Preferred Stock has
been converted, and payment of any declared but unpaid dividends thereon and any
dividends or distributions required to be declared under Section 1(a). If so
required by the Corporation, certificates surrendered for conversion shall be
endorsed or accompanied by written instrument or instruments of transfer, in
form satisfactory to the Corporation, duly executed by the registered holder or
by his or its attorney duly authorized in writing. As soon as practicable after
the Mandatory Conversion Date and the surrender of the certificate or
certificates for Series A Preferred Stock, the Corporation shall cause to be
issued and delivered to such holder, or on his or its written order, a
certificate or certificates for the number of full shares of Common Stock
issuable on such conversion in accordance with the provisions hereof and cash as
provided in Subsection 4(b) in respect of any fraction of a share of Common
Stock otherwise issuable upon such conversion.

     (c) All certificates evidencing shares of Series A Preferred Stock which
are required to be surrendered for conversion in accordance with the provisions
hereof shall, from and after the Mandatory Conversion Date, be deemed to have
been retired and cancelled and the shares of Series A Preferred Stock
represented thereby converted into Common Stock for all purposes,
notwithstanding the failure of the holder or holders thereof to surrender such
certificates on or prior to such date. The Corporation may thereafter take such
appropriate action (without the need for stockholder action) as may be necessary
to reduce the authorized Series A Preferred Stock accordingly.

     IN WITNESS WHEREOF, the Corporation has caused its corporate seal to be
affixed hereto and this Certificate of Amendment to be signed by its President
and attested to by its Assistant Secretary this 30th day of September, 1994.

                                            SEPRACOR, INC.

                                            By: /s/ Timothy J. Barberich
                                                ------------------------

ATTEST:

/s/ Victor Woolley
------------------
Assistant Secretary


[Corporate Seal]

                                       13

<PAGE>

                            CERTIFICATE OF CORRECTION
                       FILED TO CORRECT CERTAIN ERRORS IN

                       THE CERTIFICATE OF DESIGNATIONS OF
                             THE PREFERRED STOCK OF

                                  SEPRACOR INC.

                                TO BE DESIGNATED
                      SERIES A CONVERTIBLE PREFERRED STOCK

          FILED IN THE OFFICE OF THE SECRETARY OF STATE OF DELAWARE ON
                               SEPTEMBER 30, 1994.

     SEPRACOR INC., a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware,

     DOES HEREBY CERTIFY:

     1.  The name of the corporation is Sepracor Inc.

     2.  The Certificate of Designations of the Preferred Stock of Sepracor Inc.
         to be designated Series A Convertible Preferred Stock was filed with
         the Secretary of State of the State of Delaware on September 30, 1994
         and that said certificate requires corrections permitted by subsection
         (f) of Section 103 of the General Corporation Law of the State of
         Delaware.

     3.  The inaccuracies or defects of said certificate to be corrected are as
         follows:

         (a)  Certain words were inadvertently omitted from Subsection (b) of
              Section 3;

         (b)  A typographical error is included in Subsection (d)(i)(D)(I) of
              Section 4;

         (c)  Subsection (d)(i)(E) of Section 4 was inadvertently located within
              subsection (d)(i)(D);

         (c)  The final page of said certificate was inadvertently numbered as
              page 15.

     In order to correct said inaccuracies or defects, the following shall
occur:

         (a)  Subsection (b) of Section 3 shall read in its entirety:

                                        1

<PAGE>

              Without the consent of the holders of a majority of the shares of
              Series A Preferred Stock then outstanding, the Corporation shall
              not enter into any merger or consolidation (except one in which
              the holders of capital stock of the Corporation immediately prior
              to such merger or consolidation continue to hold at least 60% by
              voting power of the capital stock of the surviving corporation) or
              the sale of substantially all the assets of the Corporation where
              the consideration payable to the holders of the Series A Preferred
              Stock shall have a value less than $63.00 per share in the same
              form as the consideration being given to the majority of shares of
              Common Stock with the value being determined by an independent
              appraiser.";

         (b)  The words "Original Issuance Date" in Subsection (d)(i)(D)(I) of
              Section 4 shall be changed to "Original Issue Date.";

         (c)  Subsection (d)(i)(E) of Section 4, shall be relocated to
              immediately follow subsection (d)(i)(D)(VI) of Section 4;

         (d)  The final page shall be renumbered as page 16.

     IN WITNESS WHEREOF, said Sepracor Inc. has caused this certificate to be
signed by Timothy J. Barberich, its President, and attested by Victor H.
Woolley, its Assistant Secretary, this 28 day of October, 1994.

                                            SEPRACOR INC.


                                            By: /s/ Timothy J. Barberich
                                                ------------------------
                                                President

ATTEST:

By: /s/ Victor Woolley
    ------------------
    Assistant Secretary

                                        2

<PAGE>

                    CERTIFICATE OF DESIGNATIONS, PREFERENCES,
                    AND RELATIVE, PARTICIPATING, OPTIONAL AND
                     OTHER SPECIAL RIGHTS OF PREFERRED STOCK
                         AND QUALIFICATIONS, LIMITATIONS
                            AND RESTRICTIONS THEREOF

                                       OF

                SERIES B REDEEMABLE EXCHANGEABLE PREFERRED STOCK
                                       OF

                                  SEPRACOR INC.

                         Pursuant to Section 151 of the
                General Corporation Law of the State of Delaware

     Sepracor Inc., a Delaware corporation (the "Corporation"), certifies that
pursuant to the authority contained in Article FOURTH of its Restated
Certificate of Incorporation (the "Certificate of Incorporation") and in
accordance with the provisions of Section 151 of the General Corporation Law of
the State of Delaware, the Board of Directors of the Corporation, at a meeting
duly called and held, at which a quorum was present and acting throughout, duly
adopted the following resolution, which resolution remains in full force and
effect on the date hereof:

     RESOLVED, that there is hereby established a series of authorized Preferred
Stock having a par value of $1.00 per share, which series shall be designated
"Series B Redeemable Exchangeable Preferred Stock" (hereinafter "Series B
Preferred Stock"), shall consist of 312,500 shares and shall have the following
powers, preferences and relative, participating, optional and other special
rights, and qualifications, limitations and restrictions thereof:

     1. Dividends. Holders of shares of Series B Preferred Stock shall be
entitled to receive, when, as and if declared by the Board of Directors out of
funds legally available therefor, an annual cash dividend of $1.92 per share,
payable on each March 8 after the date of issuance of Series B Preferred Stock
until March 8, 2000. Such dividends shall accrue from day to day and shall be
cumulative from the date of issuance of each share of Series B Preferred Stock,
whether or not declared. After March 8, 2000, no dividends shall accrue on
outstanding shares of Series B Preferred Stock. Dividends will be payable to
holders of record as they appear on the stock records of the Corporation on such
record dates, not more than 60 days preceding the applicable payment date, as
shall be fixed by the Board of Directors of the Corporation. Dividends payable
for any partial period shall be calculated on the basis of a 360-day year, and
accrued but unpaid dividends shall not bear interest.

                                        3

<PAGE>

     2. Liquidation, Dissolution or Winding Up: Certain Mergers and
Consolidations.

        (a) In the event of any voluntary or involuntary liquidation,
dissolution or winding up of the Corporation, the holders of shares of Series B
Preferred Stock then outstanding shall be entitled to be paid out of the assets
of the Corporation available for distribution to its stockholders, after and
subject to payment in full of all amounts required to be distributed to any
class or series of stock of the Corporation ranking on liquidation prior and in
preference to the Series B Preferred Stock (such stock being collectively
referred to as the "Senior Preferred Stock"), but before any payment shall be
made to the holders of the common stock, par value $0.10 per share, of the
Corporation ("Common Stock") or any other class or series of stock ranking on
liquidation junior to the Series B Preferred Stock (such Common Stock and other
stock being collectively referred to as "Junior Stock") by reason of their
ownership thereof, an amount equal to $16.00 per share (subject to appropriate
adjustment in the event of any stock dividend, stock split, combination or other
similar recapitalization affecting such shares), plus any dividends declared or
accrued but unpaid on such shares. The Series A Convertible Preferred Stock of
the Corporation (the "Series A Preferred Stock") shall rank on liquidation on a
parity with the Series B Preferred Stock. If upon any such liquidation,
dissolution or winding up of the Corporation the remaining assets of the
Corporation available for distribution to the stockholders shall be insufficient
to pay the holders of shares of Series A Preferred Stock and Series B Preferred
Stock the full amount to which they shall be entitled, the holders of shares of
Series A Preferred Stock, Series B Preferred Stock and any class or series of
stock ranking on liquidation on a parity with the Series A Preferred Stock and
the Series B Preferred Stock shall share ratably in any distribution of the
remaining assets and funds of the Corporation in proportion to the respective
amounts which would otherwise be payable in respect of the shares held by them
upon such distribution if all amounts payable on or with respect to such shares
were paid in full.

        (b) After the payment of all preferential amounts required to be paid to
the holders of Senior Preferred Stock, Series A Preferred Stock, Series B
Preferred Stock and any other class or series of stock of the Corporation
ranking on liquidation on a parity with the Series B Preferred Stock, upon the
dissolution, liquidation or winding up of the Corporation, the holders of shares
of Junior Stock then outstanding shall be entitled to receive the remaining
assets and funds of the Corporation available for distribution to its
stockholders.

        (c) At least 20 days prior to the date of any dissolution, liquidation
or winding up of the Corporation, the Corporation shall give notice thereof in
the manner provided by Section 5(c) hereof in order to permit the holders of
Series B Preferred Stock to exercise their right to exchange such shares before
their Exchange Rights (as defined in Section 5 hereof) terminate.

                                        4

<PAGE>

        (d) In the event of any merger or consolidation pursuant to which
holders of outstanding shares of Common Stock exchange such shares for cash,
property and/or securities of another corporation or entity (a "Qualified
Merger"), then such merger or consolidation shall be deemed to be a liquidation
of the Corporation for purposes of this Section 2.

     3. Voting. Except as otherwise required by law, holders of Series B
Preferred Stock shall not be entitled to any voting rights by virtue of such
ownership.

     4. Restriction on Creation of Certain Senior Shares. So long as any Series
B Preferred Stock shall be outstanding, the Corporation shall not, without the
prior written approval of holders of a majority of the Series B Preferred Stock
then outstanding, create any class or series of stock ranking, as to payment of
dividends or liquidation preference, equal or prior to the Series B Preferred
Stock if the terms of such stock in any way restrict the Corporation's ability
to comply with the powers, preferences and special rights of the Series B
Preferred Stock other than in connection with the operation of the preference
upon liquidation, dissolution or winding up (or deemed liquidation) of such
other class or series of stock as set forth in Section 2 hereof.

     5. Optional Exchange. The holders of Series B Preferred Stock shall have
exchange rights as follows (the "Exchange Rights"):

        (a) Right to Exchange.

            (i) At any time after the earlier of (A) 20 days prior to March 8,
2000, (b) the date, prior to March 8, 2000, on which the shares of common stock,
$0.01 par value per share (the "BioSepra Common Stock"), of BioSepra Inc., a
Delaware corporation ("BioSepra") have a closing price as reported by the Wall
Street Journal (or if the Wall Street Journal is not then being published,
publications of similar reliability and repute), greater than 112.5% of the
Exchange Price (as determined in accordance with the provisions of this Section
5), (C) 20 days prior to a BioSepra Event (as defined in Subsection 5(a)(ii)
below), (D) 20 days prior to the date of any redemption made pursuant to Section
6 or 7 hereof or (E) 20 days prior to the date of any dissolution, liquidation
or winding up of the Corporation pursuant to Section 2 hereof, subject to funds
legally available therefor, each share of Series B Preferred Stock shall be
exchangeable, at the option of the holder thereof, and without the payment of
additional consideration by the holder thereof, for such number of outstanding
shares of BioSepra Common Stock held by the Corporation (the "Owned BioSepra
Common Stock") as is determined by dividing $16.00 by the Exchange Price (as
defined below) in effect at the time of exchange. The "Exchange Price" shall
initially be $16.00. Such initial Exchange Price, and the rate at which shares
of Series B Preferred Stock may be exchanged for shares of BioSepra Common
Stock, shall be subject to adjustment as provided below. No declared or accrued
but

                                        5

<PAGE>

unpaid dividends shall be paid upon such exchange.

            (ii) In the event of a Change of Control of BioSepra, as defined in
Section 7(b) hereof (a "BioSepra Event"), the Exchange Rights may be exercised
at the option of each holder of Series B Preferred Stock prior to the
effectiveness of the BioSepra Event pursuant to the following:

                  (A) The Corporation shall use its best efforts to provide
written notice to each holder of Series B Preferred Stock at least 20 days prior
to the date on which the BioSepra Event is expected to become effective,
notifying such holder of (I) the date on which the BioSepra Event is expected to
become effective and (II) the date as of which the holders of record of BioSepra
Common Stock shall be entitled to any consideration to be paid to such holders
pursuant to the BioSepra Event; and

                  (B) Subsequent to the receipt of such written notice pursuant
to clause (A) above by each holder of Series B Preferred Stock, the Corporation
and each holder of such stock shall use their respective best efforts to
effectuate such an optional exchange (pursuant to the provisions of Subsection
5(a)(i) hereof and Section 5(c) hereof) to insure that those holders of Series B
Preferred Stock who exercise their Exchange Rights shall be holders of BioSepra
Common Stock prior to the effectiveness of the BioSepra Event.

            (iii) In the event of a notice of any redemption of shares of Series
B Preferred Stock pursuant to Sections 6 or 7 hereof, the Exchange Rights of the
holders of the shares designated for redemption shall terminate at the close of
business on the second full day preceding the date fixed for redemption, unless
the redemption price is not paid when due, in which case the Exchange Rights for
such shares shall continue until such price is paid in full. In the event of a
liquidation of the Corporation pursuant to Section 2 hereof, the Exchange Rights
shall terminate at the close of business on the first full day preceding the
date fixed for the payment of any amounts distributable on liquidation to the
holders of Series B Preferred Stock.

            (iv) With respect solely to shares of BioSepra Common Stock obtained
pursuant to an exchange governed by Sections 5(a)(i)(B) or 5(a)(i)(C) above,
holders of such shares of BioSepra Common Stock shall, upon such exchange,
provide a proxy to the Board of Directors of the Corporation or their designees
(expiring on March 8, 2000) for the voting of such shares with respect to any
vote of the stockholders of BioSepra regarding any BioSepra Event.

     (b) Fractional Shares. No fractional share of BioSepra Common Stock shall
be issued upon exchange of the Series B Preferred Stock. In lieu of any
fractional shares to which the holder would otherwise be entitled, the
Corporation shall pay cash equal to such fraction multiplied by the then
effective Exchange Price.

                                        6

<PAGE>



     (c) Mechanics of an Optional Exchange.

         (i) In order for each holder of Series B Preferred Stock to exchange
shares of Series B Preferred Stock for shares of BioSepra Common Stock, such
holder shall surrender the certificate or certificates for such shares of Series
B Preferred Stock at the principal office of the Corporation, together with
written notice to the Corporation that such holder elects to exchange all or any
number of the shares of Series B Preferred Stock represented by such certificate
or certificates. Such notice shall state such holder's name or the names of the
nominees in which such holder wishes the certificate or certificates for shares
of BioSepra Common Stock to be issued. If required by the Corporation,
certificates surrendered for exchange shall be endorsed or accompanied by a
written instrument or instruments of transfer, in form reasonably satisfactory
to the Corporation, duly executed by the registered holder or his or its
attorney duly authorized in writing. The date of receipt of such certificates
and notice by the Corporation shall be the exchange date (the "Exchange Date").
The Corporation shall, as soon as practicable after the Exchange Date, deliver
at such office to such holder of Series B Preferred Stock, or to his or its
nominees, a certificate or certificates for the number of shares of BioSepra
Common Stock to which such holder shall be entitled, together with cash in lieu
of any fraction of a share. On and after the Exchange Date, such holder or his
or its nominees shall be deemed to be the record owner of such shares of
BioSepra Common Stock and have all the rights appertaining thereto.

         (ii) The Corporation shall at all times when the Series B Preferred
Stock shall be outstanding, reserve for the purpose of effecting the exchange of
the Series B Preferred Stock, such number of its shares of BioSepra Common Stock
as shall from time to time be sufficient to effect the exchange of all
outstanding Series B Preferred Stock.

         (iii) All shares of Series B Preferred Stock which shall have been
surrendered for exchange as herein provided shall no longer be deemed to be
outstanding and all rights with respect to such shares, including the right, if
any, to receive notices and to vote, shall immediately cease and terminate on
the Exchange Date, except only the right of the holders thereof to receive
certificates representing shares of BioSepra Common Stock in exchange therefor.
Any shares of Series B Preferred Stock so exchanged shall be retired and
cancelled and shall not be reissued, and the Corporation (without the need for
stockholder action) may from time to time take such appropriate action as may be
necessary to reduce the authorized Series B Preferred Stock accordingly.

     (d) Adjustments to Exchange Price for Diluting Issues:

         (i) Special Definitions. For purposes of this Section 5(d), the
following definitions shall apply:

                                        7

<PAGE>

             (A) "Option" shall mean rights, options or warrants to subscribe
for, purchase or otherwise acquire BioSepra Common Stock or Exchangeable
Securities (as defined below), excluding options granted to persons described in
Subsection 5(d)(i)(D)(IV) hereof.

             (B) "Original Issue Date" shall mean March 8, 1995.

             (C) "Exchangeable Securities" shall mean any evidences of
indebtedness, shares or other securities directly or indirectly convertible into
or exchangeable for BioSepra Common Stock.

             (D) "Additional Shares of BioSepra Common Stock" shall mean all
shares of BioSepra Common Stock issued (or, pursuant to Subsection 5(d)(iii)
hereof, deemed to be issued) by BioSepra after the Original Issue Date, other
than shares issued or issuable:

                 (I)   upon exercise of any warrants or options or conversion of
                       any convertible securities of BioSepra outstanding
                       immediately prior to the Original Issue Date;

                 (II)  by reason of a dividend, stock split, split-up or other
                       distribution on shares of BioSepra Common Stock that is
                       covered by Subsection 5(e) or 5(f) hereof;


                 (III) in connection with the acquisition by BioSepra of another
                       corporation or business;


                 (IV)  to employees or directors of, or consultants to, BioSepra
                       or any subsidiary as approved by the Board of Directors
                       of BioSepra; or

                 (V)   to pharmaceutical companies or other strategic partners
                       in connection with a licensing, development, joint
                       venture or similar arrangement between BioSepra and such
                       company or partner.

             (E) The BioSepra Common Stock shall be deemed to include any equity
security having rights to receive dividends or distributions (including
liquidation) not limited to a fixed sum or percentage of the purchase price
therefor.

             (F) "Initial Shares Outstanding" shall mean the number of shares of
BioSepra Common Stock issued and outstanding immediately prior to an adjustment
of the Exchange Price pursuant to Subsection 5(d)(iv) hereof.

     (ii) No Adjustment of Exchange Price. No adjustment in the number of shares
of BioSepra Common Stock into which the Series B Preferred Stock is

                                        8

<PAGE>

exchangeable shall be made, by adjustment in the applicable Exchange Price
thereof: (a) unless the consideration per share (determined pursuant to
Subsection 5(d)(v) hereof) for an Additional Share of BioSepra Common Stock
issued or deemed to be issued by BioSepra is less than the applicable Exchange
Price in effect on the date of, and immediately prior to, the issue of such
Additional Shares, or (b) if prior to such issuance, the Corporation receives
written notice from the holders of at least a majority of the then outstanding
shares of Series B Preferred Stock agreeing that no such adjustment shall be
made as the result of the issuance of Additional Shares of BioSepra Common
Stock.

     (iii) Issue of Securities Deemed Issue of Additional Shares of BioSepra
Common Stock.

     If BioSepra at any time or from time to time after the Original Issue Date
shall issue any Options or Exchangeable Securities or shall fix a record date
for the determination of holders of any class of securities entitled to receive
any such options or Exchangeable Securities, then the maximum number of shares
of BioSepra Common Stock (as set froth in the instrument relating thereto
without regard to any provision contained therein for a subsequent adjustment of
such number) issuable upon the exercise of such Options or, in the case of
Exchangeable Securities and Options therefor, the conversion or exchange of such
Exchangeable Securities, shall be deemed to be Additional Shares of BioSepra
Common Stock issued as of the time of such issue or, in case such a record date
shall have been fixed, as of the close of business on such record date, provided
that Additional Shares of BioSepra Common Stock shall not be deemed to have been
issued unless the consideration per share (determined pursuant to Subsection
5(d)(v) hereof) of such Additional Shares of BioSepra Common Stock would be less
than the applicable Exchange Price in effect on the date of and immediately
prior to such issue, or such record date, as the case may be, and provided
further that in any such case in which Additional Shares of BioSepra Common
Stock are deemed to be issued:

            (A) No further adjustment in the Exchange Price shall be made upon
the subsequent issue of Exchangeable Securities or shares of BioSepra Common
Stock upon the exercise of such Options or conversion or exchange of such
Exchangeable Securities;

            (B) If such Options or Exchangeable Securities by their terms
provide, with the passage of time or otherwise, for any increase or decrease in
the consideration payable to the Corporation, upon the exercise, conversion or
exchange thereof, the Exchange Price computed upon the original issue thereof
(or upon the occurrence of a record date with respect thereto), and any
subsequent adjustments based thereon, shall, upon any such increase or decrease
becoming effective, be recomputed to reflect such increase or decrease, as
applicable, insofar as it affects such Options or the rights of conversion or
exchange under such Exchangeable

                                        9

<PAGE>

Securities;

            (C) Upon the expiration or termination of any unexercised Option,
the Exchange Price shall not be readjusted; and

            (D) No readjustment pursuant to clause (B) above shall have the
effect of increasing the Exchange Price to an amount which exceeds the lower of
(I) the Exchange Price on the original adjustment date, or (II) the Exchange
Price that would have resulted from any issuances of Additional Shares of
BioSepra Common Stock between the original adjustment date and such readjustment
date.

     (iv) Adjustment of Exchange Price Upon Issuance of Additional Shares of
BioSepra Common Stock.

     In the event BioSepra shall at any time after the Original Issue Date issue
Additional Shares of BioSepra Common Stock (including Additional Shares of
BioSepra Common Stock deemed to be issued pursuant to Subsection 5(d)(iii)
hereof, but excluding shares issued upon a stock split or combination as
provided in Section 5(e) hereof or as a dividend or distribution as provided in
Section 5(f) hereof), without consideration or for a consideration per share
less than the applicable Exchange Price in effect on the date of and immediately
prior to such issue, then and in such event, such Exchange Price shall be
reduced, concurrently with such issue, to a price equal to the greater of (i)
$12.00 (as proportionately adjusted in the event the Exchange Price is or has
been subject to adjustment pursuant to Sections 5(e) or 5(f) hereof) and (ii)
such Exchange Price multiplied by a fraction, the numerator of which is the
Initial Shares Outstanding and the denominator of which is the Initial Shares
Outstanding plus the number of such Additional Shares of BioSepra Common Stock.

     (v) Determination of Consideration. For purposes of this Section 5(d), the
consideration received by BioSepra for the issue of any Additional Shares of
BioSepra Common Stock shall be computed as follows:

            (A) Cash and Property: Such consideration shall:

                 (I)   insofar as it consists of cash, be computed at the
                       aggregate of cash received by BioSepra, excluding amounts
                       paid or payable for accrued interest or accrued
                       dividends;

                 (II)  (insofar as it consists of property other than cash, be
                       computed at the fair market value thereof at the time of
                       such issue, as reasonably determined by the Board of
                       Directors of BioSepra; and

                                       10

<PAGE>



                 (III) (in the event Additional Shares of BioSepra Common Stock
                       are issued together with other shares or securities or
                       other assets of BioSepra for consideration which covers
                       both, be the proportion of such consideration so
                       received, computed as provided in clauses (I) and (II)
                       above, as reasonably determined by the Board of Directors
                       of BioSepra.

            (B) Options and Exchangeable Securities. The consideration per share
received by BioSepra for Additional Shares of BioSepra Common Stock deemed to
have been issued pursuant to Subsection 5(d)(iii) hereof, relating to Options
and Exchangeable Securities, shall be determined by dividing:

                (x) the total amount, if any, received or receivable by BioSepra
as consideration for the issue of such Options or Exchangeable Securities, plus
the minimum aggregate amount of additional consideration (as set forth in the
instruments relating thereto, without regard to any provision contained therein
for a subsequent adjustment of such consideration) payable to BioSepra upon the
exercise of such Options or the conversion or exchange of such Exchangeable
Securities, or in the case of Options for Exchangeable Securities, the exercise
of such Options for Exchangeable Securities and the conversion or exchange of
such Exchangeable Securities, by

                (y) the maximum number of shares of BioSepra Common Stock (as
set forth in the instruments relating thereto, without regard to any provision
contained therein for a subsequent adjustment of such number) issuable upon the
exercise of such Options or the conversion or exchange of such Exchangeable
Securities.

     (e) Adjustment for Stock Splits and Combinations. If BioSepra shall at any
time or from time to time after the Original Issue Date effect a subdivision of
the outstanding BioSepra Common Stock, the Exchange Price then in effect
immediately before that subdivision shall be proportionately decreased. If
BioSepra shall at any time or from time to time after the Original Issue Date
combine the outstanding shares of BioSepra Common Stock, the Exchange Price then
in effect immediately before the combination shall be proportionately increased.
Any adjustment under this Section 5(e) shall become effective at the close of
business on the date the subdivision or combination becomes effective.

     (f) Adjustment for Certain Dividends and Distributions. In the event
BioSepra at any time, or from time to time after the Original Issue Date shall
make or issue, or fix a record date for the determination of holders of BioSepra
Common Stock entitled to receive, a dividend or other distribution payable in
additional shares

                                       11

<PAGE>

of BioSepra Common Stock, then and in each such event the Exchange Price for the
Series B Preferred Stock then in effect shall be decreased as of the time of
such issuance or, in the event such a record date shall have been fixed, as of
the close of business on such record date, by multiplying the Exchange Price for
the Series B Preferred Stock then in effect by a fraction:

                           (x) the numerator of which shall be the total number
                  of shares of BioSepra Common Stock issued and outstanding
                  immediately prior to the time of such issuance or the close of
                  business on such record date; and

                           (y) the denominator of which shall be the total
                  number of shares of BioSepra Common Stock issued and
                  outstanding immediately prior to the time of such issuance or
                  the close of business on such record date plus the number of
                  shares of BioSepra Common Stock issuable in payment of such
                  dividend or distribution;

provided, however, that if such record date shall have been fixed and such
dividend is not fully paid or if such distribution is not fully made on the date
fixed therefor, the Exchange Price for the Series B Preferred Stock shall be
recomputed accordingly as of the close of business on such record date and
thereafter the Exchange Price for the Series B Preferred Stock shall be adjusted
pursuant to this Section 5(f) as of the time of actual payment of such dividends
or distributions.

     (g) Adjustments for Other Dividends and Distributions. In the event
BioSepra at any time after the Original Issue Date shall make or issue, or fix a
record date for the determination of holders of BioSepra Common stock entitled
to receive, a dividend or other distribution payable in securities of BioSepra
other than shares of BioSepra Common Stock, then and in each such event the
Corporation shall make provision so that the holders of the Series B Preferred
Stock shall receive upon exchange thereof in addition to the number of shares of
BioSepra Common Stock receivable thereupon, the amount of securities of BioSepra
that they would have received had the Series B Preferred Stock been exchanged
for BioSepra Common Stock immediately prior to the date of such event and had
they thereafter, during the period from the date of such event to and including
the Exchange Date, retained such securities receivable by them as aforesaid
during such period, giving application to all adjustments called for during such
period under this Section 5(g) with respect to the rights of the holders of
Series B Preferred Stock.

     (h) Adjustment for Reclassification, Exchange or Substitution. If the
BioSepra Common Stock issuable upon the exchange of the Series B Preferred Stock
shall be changed into the same or a different number of shares of any class or
classes of stock, whether by capital reorganization, reclassification, or
otherwise (other than a subdivision or combination of shares or stock dividend
provided for above, or a

                                       12

<PAGE>

reorganization, merger, consolidation, or sale of assets provided for below),
then and in each such event the holder of each such share of Series B Preferred
Stock shall have the right thereafter to exchange such share into the kind and
amount of shares of stock and other securities and property receivable upon such
reorganization, reclassification, or other change, by holders of the number of
shares of BioSepra Common Stock for which such shares of Series B Preferred
Stock might have been exchanged immediately prior to such reorganization,
reclassification, or change, all subject to further adjustment as provided
herein.

     (i) Adjustment for Merger or Reorganization, etc. In case of any
consolidation or merger of BioSepra with or into another corporation or the sale
of all or substantially all of the assets of BioSepra to another corporation,
each share of Series B Preferred Stock shall thereafter be exchangeable (or
shall be exchanged for a security which shall be exchangeable) for the kind and
amount of shares of stock or other securities or property to which a holder of
the number of shares of BioSepra Common Stock deliverable upon exchange of such
Series B Preferred Stock would have been entitled upon such consolidation,
merger or sale.

     (j) No Impairment. Without limiting the foregoing, the Corporation shall
use its best efforts to cause BioSepra to carry out all the provisions of this
Section 5 and to cause BioSepra to take all such action as may be necessary or
appropriate in order to protect the Exchange Rights of the holders of Series B
Preferred Stock against impairment.

     (k) Certificate as to Adjustments. Upon the occurrence of each adjustment
or readjustment of the Exchange Price pursuant to this Section 5, the
Corporation at its expense shall promptly compute such adjustment or
readjustment in accordance with the terms hereof and furnish to each holder of
Series B Preferred Stock a certificate setting forth such adjustment or
readjustment and showing in detail the facts upon which such adjustment or
readjustment is based.

     6. Optional Redemption.

        (a) Qualified Merger. At any time after the date on which the
Corporation has entered into a definitive agreement relating to a Qualified
Merger (as defined in Section 2(d) hereof), the Corporation may redeem all, but
not less than all, of the Series B Preferred Stock by paying a redemption price
of $16.00 plus any declared or accrued but unpaid dividends in cash, for each
share of Series B Preferred Stock then redeemed.

        (b) Notice of Section 6(a) Redemption. At least 10 days prior to the
date fixed for any redemption of Series B Preferred Stock pursuant to Section
6(a) hereof, the Corporation shall provide written notice of the redemption of
Series B Preferred Stock to each holder of record of Series B Preferred Stock to
be redeemed,

                                       13

<PAGE>

notifying such holder of the election of the Corporation to redeem such shares,
specifying the redemption date, the time and date at which such holder's
Exchange Rights (pursuant to Section 5 hereof), if any, as to such shares
terminate (which shall be the close of business on the second full day preceding
the redemption date) and the section of this resolution pursuant to which such
redemption is being made and calling upon such holder to surrender to the
Corporation, in the manner and at the place designated, his or its certificate
or certificates representing the shares to be redeemed (such notice is
hereinafter referred to as the "Redemption Notice"). On or prior to the
redemption date, each holder of Series B Preferred Stock to be redeemed shall
surrender his or its certificate or certificates representing such shares to the
Corporation, in the manner and at the place designated in the Redemption Notice,
and thereupon the redemption price of such shares shall be payable to the order
of the person whose name appears on such certificate or certificates as the
owner thereof and each surrendered certificate or certificates as the owner
thereof and each surrendered certificate shall be cancelled. From and after such
redemption date, unless there shall have been a default in payment of the
redemption price, all rights of the holders of Series B Preferred Stock
designated for redemption in the Redemption Notice as holders of Series B
Preferred Stock (except the right to receive the redemption price, and interest
thereon at the rate of 10% per annum if the redemption price is not paid when
due, upon surrender of their certificate or certificates) shall cease with
respect to such shares, and such shares shall not thereafter be transferred on
the books of the Corporation or be deemed to be outstanding for any purpose
whatsoever. Notwithstanding the foregoing, if said 10% rate of interest is in
excess of the rate permitted under applicable usury laws, said rate shall be
reduced to the maximum interest rate permissible under said usury laws.

     7. Mandatory Redemption.

        (a) March 8, 2000 and Notice Thereof. The Corporation shall, on March 8,
2000, redeem for cash all outstanding shares of Series B Preferred Stock at a
redemption price equal to $16.00 per share, plus any dividends declared or
accrued but unpaid thereon. The notice provisions of Section 6(b) hereof shall
apply to a mandatory redemption pursuant to this Section 7(a).

        (b) Change of Control of BioSepra Inc. If, at any time on or prior to
March 8, 2000, there is a Change of Control (as defined below) of BioSepra, the
Corporation (or any successor in interest to the Corporation) shall, no later
than five business days after such Change of Control, redeem for cash all
outstanding shares of Series B Preferred Stock at a redemption price equal to
one of the following:

            (i) $25.60 per share of Series B Preferred Stock if the BioSepra
Market Capitalization (as defined below) is $120,031,950 or less;

                                       14

<PAGE>

            (ii) $32.00 per share of Series B Preferred Stock if the BioSepra
Market Capitalization is between $120,031,950 and $168,044,730; or

            (iii) $48.00 per share of Series B Preferred Stock if the BioSepra
Market Capitalization is $168,044,730 or more.

         No declared or accrued but unpaid dividends with respect to the Series
B Preferred Stock shall be paid upon a redemption made pursuant to this Section
7(b).

     A "Change of Control" of BioSepra shall occur or be deemed to have occurred
if any of the following events occur: (A) any "person," as such term is used in
Section 13(d) of the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), (other than the Corporation (or its successor), Beckman Instruments, Inc.
(or its affiliate) or a holder of Series B Preferred Stock (or an affiliate of
such holder), any trustee or other fiduciary holding securities under an
employee benefit plan of BioSepra, or any corporation owned directly or
indirectly by the stockholders of BioSepra in substantially the same proportion
as their ownership of stock of BioSepra) is or becomes the "beneficial owner"
(as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of
securities of BioSepra representing 30% or more of the combined voting power of
BioSepra's then outstanding securities and the Corporation is not or ceases to
be the beneficial owner of securities of BioSepra representing a greater
percentage of such combined voting power than held by such person; (B)
individuals who, as of March 8, 1995, constitute at least a majority of the
Board of Directors of BioSepra (as of the date hereof, the "Incumbent Board")
cease for any reason to constitute at least a majority of the Board of Directors
of BioSepra, provided that any person becoming a director subsequent to March 8,
1995 whose election, or nomination for election by BioSepra's stockholders, was
approved by a vote of at least a majority of the directors then comprising the
Incumbent Board (other than an election or nomination of an individual whose
initial assumption of office is in connection with an actual or threatened
election contest relating to the election of the directors of BioSepra, as such
terms are used in Rule 14a-11 of Regulation 14A under the Exchange Act) shall
be, for purposes hereof, considered as though such person were a member of the
Incumbent Board; (C) the stockholders of BioSepra approve a merger or
consolidation of BioSepra with any other corporation (other than Beckman
Instruments, Inc. (or its affiliate) or a holder of Series B Preferred Stock (or
an affiliate of such holder)), other than (I) a merger or consolidation which
would result in the voting securities of BioSepra outstanding immediately prior
thereto continuing to represent (either by remaining outstanding or by being
converted into voting securities of the surviving entity) more than a majority
of the combined voting power of the voting securities of BioSepra or such
surviving entity outstanding immediately after such merger or consolidation or
(II) a merger or consolidation effected to implement a recapitalization of
BioSepra (or similar transaction) in which no "person" (as hereinabove defined)
acquires more than 30% of the combined voting power of BioSepra's then
outstanding securities; or (D) the stockholders of BioSepra approve a

                                       15

<PAGE>

plan of complete liquidation of BioSepra or an agreement for the sale or
disposition by BioSepra of all or any substantial portion of BioSepra's assets;
provided, however, that unless one or more of the events or conditions specified
above shall have occurred, a change of control of the Corporation pursuant to a
merger, consolidation, sale of stock or assets, or otherwise, without more shall
not be deemed to be a Change of Control of BioSepra.

     "BioSepra Market Capitalization" shall mean, for the purpose of this
Section 7(b), the product of (A) the BioSepra Share Price (as defined below) and
(B) the number of shares issued and outstanding of BioSepra Common Stock plus
the number of shares issuable upon the exercise, conversion or exchange of
outstanding options, warrants, convertible or exchangeable securities or other
rights to acquire shares of BioSepra Common Stock, whether vested or unvested.

     The "BioSepra Share Price" shall mean the average closing price per share
of BioSepra Common Stock, as reported by the Wall Street Journal (or if the Wall
Street Journal is not then being published, publications of similar reliability
and repute), for the three consecutive trading days immediately preceding a
Change of Control.

        (c) Notice of Section 7(b) Redemption. The Corporation shall provide
written notice of the redemption of the Series B Preferred Stock pursuant to
Section 7(b) hereof to each holder of record of Series B Preferred Stock to be
redeemed as soon as possible, but no less than three calendar days, prior to the
date on which such redemption is to be made. Except as provided in the preceding
sentence, the notice provisions of Section 6(b) hereof shall apply to a
mandatory redemption pursuant to Section 7(b) hereof.

     8. Early Redemption at Election of Holders.

        (a) Upon the written request of the holders of a majority of the then
outstanding shares of Series B Preferred Stock (the "Majority Requesting
Holder(s)") received by the Corporation at least 90 days prior to Monday, March
10, 1997, on March 10, 1997 and on each of the first, second and third
anniversaries thereof (each such date being referred to hereinafter as an "Early
Redemption Date", the Corporation will redeem from each holder of shares of
Series B Preferred Stock, at a price per share as set forth below, subject to
appropriate adjustment in the event of any stock dividend, stock split,
combination or other similar recapitalization affecting such shares (the "Early
Redemption Price"), the following respective portions of the number of shares of
Series B Preferred Stock held by each such holder on the applicable Early
Redemption Date:

                                       16

<PAGE>

<TABLE>
<CAPTION>
                                                 Portion of the Then
                                                     Outstanding
                                                      Shares of
                                                  Series B Preferred                          Per Share
            Redemption Date                      Stock to be Redeemed                      Redemption Price
            ---------------                      --------------------                      ----------------
<S>                                              <C>                                       <C>
March 10, 1997                                           25%                                    $17.98
March 10, 1998                                         33 1/3%                                  $19.06
March 10, 1999                                           50%                                    $20.20
March 10, 2000                                   All then outstanding                           $21.41
                                                  shares of Series B
                                                   Preferred Stock
</TABLE>


     No declared or accrued but unpaid dividends with respect to the Series B
Preferred Stock shall be paid upon a redemption made pursuant to this Section
8(a).

        (b) No later than 20 days after receipt of the written notice from the
Majority Requesting Holder(s) pursuant to Section 8(a) hereof, the Corporation
shall provide written notice of the applicable early redemption of Series B
Preferred Stock to each other holder of record of such stock, notifying such
holder of the election of the Majority Requesting Holder(s) to redeem such
shares, the Early Redemption Price and the applicable Early Redemption Date.

        (c) From and after such applicable Early Redemption Date, unless there
shall have been a default in payment of the applicable Early Redemption Price,
all rights of each holder (except the right to receive the applicable Early
Redemption Price, and interest thereon at the rate of 10% per annum if the
applicable Early Redemption Price is not paid when due, upon presentation and
surrender of their certificate or certificates) shall cease with respect to such
shares, and such shares shall not thereafter be transferred on the books of the
Corporation or be deemed to be outstanding for any purpose whatsoever.
Notwithstanding the foregoing, if said 10% rate of interest is in excess of the
rate permitted under applicable usury laws, said rate shall be reduced to the
maximum interest rate permissible under said usury laws.

     9. Deposit of Redemption Price. With respect to any redemption made
pursuant to Sections 6, 7 or 8 hereof, on or prior to the applicable redemption
date, the Corporation shall deposit the redemption price of all applicable
shares of Series B Preferred Stock with a bank or trust company having aggregate
capital and surplus in excess of $500,000,000 as a trust fund for the benefit of
the holders of Series B Preferred Stock, with irrevocable instructions and
authority to the bank or trust

                                       17

<PAGE>

company to pay the redemption price for such shares to their respective holders
on or after the redemption date upon receipt of notification from the
Corporation that such holder has surrendered his or its share certificate to the
Corporation. The balance of any monies deposited by the Corporation pursuant to
this Section 9 remaining unclaimed at the expiration of one year following the
redemption date shall thereafter be returned to the Corporation upon its request
expressed in a resolution of its Board of Directors.

     10. Purchase of Series B Preferred Stock. Nothing herein contained shall
prevent or restrict the purchase by the Corporation, from time to time either at
public or private sale, of the whole or any part of the Series B Preferred Stock
at such price or prices as the holders of Series B Preferred Stock and the
Corporation may mutually agree upon, subject to the provisions of applicable
law.

     11. Funds Legally Available. If the funds of the Corporation legally
available for redemption of Series B Preferred Stock on a redemption date are
insufficient to redeem the shares of Series B Preferred Stock required to be
redeemed on such date, those funds which are legally available will be used to
redeem the maximum possible number of such shares of Series B Preferred Stock
ratably on the basis of the number of shares of Series B Preferred Stock which
would be redeemed on such date if the funds of the Corporation legally available
therefor had been sufficient to redeem all shares of Series B Preferred Stock.
At any time thereafter when additional funds of the Corporation become legally
available for the redemption of Series B Preferred Stock, such funds will be
used, at the end of the next succeeding fiscal quarter, to redeem the balance of
the shares which the Corporation was theretofore obligated to redeem, ratably on
the basis set forth in the preceding sentence. Without limiting the foregoing,
the Corporation shall be in default when any amounts due to be paid on a
redemption date are not legally available. Holders of such unredeemed shares of
Series B Preferred Stock shall have the right to receive the applicable
redemption price and interest thereon at the rate of 10% per annum for the
period in which the Corporation is obligated to redeem such shares. If said 10%
rate of interest is in excess of the rate permitted under applicable usury laws,
said rate shall be reduced to the maximum interest rate permissible under said
usury laws.

     12. Cancellation and Subsequent Reduction of Authorized Series B Preferred
Stock. Any Series B Preferred Stock redeemed pursuant to this resolution will be
cancelled and will not under any circumstances be reissued, sold or transferred
and the Corporation may from time to time take such appropriate action as may be
necessary to reduce the authorized Series B Preferred Stock accordingly.

     13. Notices. All notices, requests, consents and other communications made
pursuant to this resolution shall be in writing and shall be delivered by hand,
telecopy (if confirmed) or mailed by first-class certified or registered mail,
return

                                       18

<PAGE>

receipt requested, postage prepaid. Such notices shall be deemed to have been
made upon dispatch to the appropriate addressee, except for such notices that
are delivered by first-class certified or registered mail, in which case such
notices shall be deemed to have been made upon receipt by the appropriate
addressee. Notice to each holder of Series B Preferred Stock shall be sent in
each case to the telecopy number or address last shown on the records of the
Corporation for such holder. Notice to the Corporation shall be sent in each
case to the telecopy number or address of an appropriate addressee located at
the Corporation's principal office.

     IN WITNESS WHEREOF, the Corporation has caused its corporate seal to be
affixed hereto and this Certificate to be duly executed by Timothy J. Barberich,
its President, this day of March, 1995.

                                            SEPRACOR INC.,
                                            a Delaware corporation

                                            By: /s/ Timothy J. Barberich
                                                ------------------------
                                                Timothy J. Barberich
                                                President

                                       19

<PAGE>

                            CERTIFICATE OF AMENDMENT

                                       OF

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                  SEPRACOR INC.

     Sepracor Inc., a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware (the "Corporation"), DOES
HEREBY CERTIFY:

     FIRST: That the Board of Directors of said Corporation, at a meeting duly
called and held on February 14, 1995, as filed with the minutes of the Board of
Directors, duly adopted a resolution pursuant to Section 242 of the General
Corporation Law of the State of Delaware proposing and declaring advisable the
following amendment to the Restated Certificate of Incorporation of the
Corporation:

RESOLVED: That the first paragraph of Article FOURTH of the Corporation's
          Restated Certificate of Incorporation be amended to read in its
          entirety as follows:

          FOURTH:   The total number of shares of all classes of stock which the
                    Corporation has authority to issue is thirty-six million
                    shares (36,000,000) consisting of thirty-five million
                    (35,000,000) shares of common stock, $.10 par value per
                    share ("Common Stock"), and one million (1,000,000) shares
                    of Preferred Stock, $1.00 par value per share ("Preferred
                    Stock").

          SECOND:   That the foregoing Amendment to the Corporation's Restated
                    Certificate of Incorporation was adopted by the holders of a
                    majority of the outstanding shares of Common Stock and
                    Series A Convertible Preferred Stock at the Corporation's
                    Annual Meeting of Stockholders held on May 17, 1995 pursuant
                    to notice duly given.

     IN WITNESS WHEREOF, Sepracor Inc. has caused this Certificate to be signed
by Timothy J. Barberich, its President, and attested by Victor H. Woolley, its
Secretary, this 17th day of May, 1995.

                                        1

<PAGE>

                                            SEPRACOR INC.


                                            By: /s/ Timothy J. Barberich
                                                ------------------------
                                                Timothy J. Barberich
                                            Its: President


ATTEST:

BY: /s/ Victor Woolley
    ------------------


                                        2

<PAGE>

                            CERTIFICATE OF AMENDMENT

                                       OF

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                  SEPRACOR INC.

     Sepracor Inc., a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware (the "Corporation"),

DOES HEREBY CERTIFY:

          FIRST:    That the Board of Directors of said Corporation, in a
                    Written Action in Lieu of Meeting dated as of March 27,
                    1996, duly adopted a resolution pursuant to Section 242 of
                    the General Corporation Law of the State of Delaware
                    ("Delaware Law") proposing and declaring advisable the
                    following amendment to the Restated Certificate of
                    Incorporation of the Corporation:

RESOLVED: That the first paragraph of Article FOURTH of the Restated Certificate
          of Incorporation, as amended, be amended to read in its entirety as
          follows:

          FOURTH:   The total number of shares of all classes of stock which the
                    Corporation has authority to issue is forty-one million
                    shares (41,000,000) consisting of forty million (40,000,000)
                    shares of common stock, $.10 par value per share ("Common
                    Stock"), and one million (1,000,000) shares of Preferred
                    Stock, $1.00 par value per share ("Preferred Stock").

          SECOND:   That the foregoing Amendment to the Corporation's Restated
                    Certificate of Incorporation, as amended, was adopted by the
                    holders of a majority of the outstanding shares of Common
                    Stock at the Corporation's Annual Meeting of Stockholders
                    held on May 15, 1996 pursuant to notice duly given.

     IN WITNESS WHEREOF, Sepracor Inc. has caused this Certificate to be signed
by Robert F. Scumaci, its Senior Vice President this 16th day of May, 1996.

                                        3

<PAGE>

                                            SEPRACOR INC.


                                            By: /s/ Robert F. Scumaci
                                                ---------------------
                                                Robert F. Scumaci
                                            Its: Senior Vice President



                                        4

<PAGE>

                            CERTIFICATE OF AMENDMENT

                                       OF

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                  SEPRACOR INC.

     Sepracor Inc., a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware (the "Corporation"), DOES
HEREBY CERTIFY:

     FIRST: That the Board of Directors of said Corporation, at a Meeting duly
called and held on February 26, 1998, as filed with the minutes of the Board of
Directors, duly adopted a resolution pursuant to Section 242 of the General
Corporation Law of the State of Delaware ("Delaware Law") proposing and
declaring advisable the following amendment to the Restated Certificate of
Incorporation, as amended, of the Corporation:

RESOLVED: That the first paragraph of Article FOURTH of the Restated Certificate
          of Incorporation, as amended, be amended to read in its entirety as
          follows:

          FOURTH: The total number of shares of all classes of stock which the
          Corporation has authority to issue is eighty-one million shares
          (81,000,000) consisting of eighty million (80,000,000) shares of
          Common Stock, $.10 par value per share ("Common Stock"), and one
          million (1,000,000) shares of Preferred Stock, $1.00 par value per
          share ("Preferred Stock").

                                        5

<PAGE>

     SECOND: That the foregoing amendment to the Corporation's Restated
Certificate of Incorporation, as amended, was adopted by the holders of a
majority of the outstanding shares of Common Stock at the Corporation's Annual
Meeting of Stockholders held on May 27, 1998 pursuant to notice duly given.

     IN WITNESS WHEREOF, Sepracor Inc. has caused this Certificate to be signed
by Robert F. Scumaci, its Senior Vice President this 3rd day of June, 1998.
SEPRACOR INC.



                                            By: /s/ Robert F. Scumaci
                                                ---------------------
                                                Robert F. Scumaci
                                                Its: Senior Vice President


                                        6
<PAGE>

                            CERTIFICATE OF AMENDMENT

                                       OF

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                  SEPRACOR INC.

     Sepracor Inc., a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware (the "Corporation"), DOES
HEREBY CERTIFY:

     FIRST: That the Board of Directors of said Corporation, at a Meeting duly
called and held on February 25, 1999, as filed with the minutes of the Board of
Directors, duly adopted a resolution pursuant to Section 242 of the General
Corporation Law of the State of Delaware ("Delaware Law") proposing and
declaring advisable the following amendment to the Restated Certificate of
Incorporation, as amended, of the Corporation:

RESOLVED: That the first paragraph of Article FOURTH of the Restated Certificate
          of Incorporation, as amended, be amended to read in its entirety as
          follows:

          FOURTH: The total number of shares of all classes of stock which the
          Corporation has authority to issue is one hundred and forty-one
          million shares (141,000,000) consisting of one hundred and forty
          million (140,000,000) shares of Common Stock, $.10 par value per
          share ("Common Stock"), and one million (1,000,000) shares of
          Preferred Stock, $1.00 par value per share ("Preferred Stock").

     SECOND: That the foregoing amendment to the Corporation's Restated
Certificate of Incorporation, as amended, was adopted by the holders of a
majority of
<PAGE>

the outstanding shares of Common Stock at the Corporation's Annual
Meeting of Stockholders held on May 19, 1999 pursuant to notice duly given.

     IN WITNESS WHEREOF, Sepracor Inc. has caused this Certificate to be signed
by Robert F. Scumaci, its Senior Vice President this 19th day of May, 1999.


                                            SEPRACOR INC.


                                            By: /s/ Robert F. Scumaci
                                                ---------------------
                                                Robert F. Scumaci
                                                Its: SENIOR VICE PRESIDENT