CHEUNG LABORATORIES, INC.

                                     BY-LAWS


                                   ARTICLE I.
                                  STOCKHOLDERS

Section 1.        ANNUAL MEETING

                  The annual  meeting  of the  stockholders  of the  Corporation
shall be held during the month of January of each year at such time as the Board
of Directors shall, in their  discretion,  fix. The business to be transacted at
the annual  meeting shall include the election of directors,  consideration  and
action upon the report of the President, and any other business within the power
of the Corporation.

Section 2.        SPECIAL MEETING

                  At any  time  in the  intervals  between  annual  meetings,  a
special  meeting of the  stockholders  may be called by the  President or by the
Board of Directors.

Section 3.        NOTICE OF MEETING

                  Not less  than ten (10) days nor more  than  ninety  (90) days
before the date of every stockholders' meeting, the Secretary shall give to each
stockholder entitled to vote at such meeting,  written or printed notice stating
the time and place of the  meeting  and, in the case of a special  meeting,  the
purpose or purposes for which the meeting is called,  either by presenting it to
him personally, by leaving it at his residence or usual place of business, or by
mailing  it to  him  at  his  address  as it  appears  on  the  records  of  the
Corporation.

                  No business shall be transacted at a special meeting save that
specially named in the notice.

                  Notwithstanding the foregoing provisions, each person entitled
to notice  waives notice if he before or after the meeting signs a waiver of the
notice which is filed with the records of stockholders  meetings,  or is present
at the meeting in person or by proxy.





Section 4.        QUORUM

                  At any meeting of  stockholders  the  presence in person or by
proxy of  stockholders  entitled to cast a majority of the votes  thereat  shall
constitute a quorum.  A majority of the votes cast at a meeting of stockholders,
duly  called and at which a quorum is  present  shall be  sufficient  to take or
authorize  action  upon any matter  which may  properly  come before the meeting
unless more than a majority  of votes is required by statute,  by the Charter of
the Corporation, or by these By-Laws.

                  In  the  absence  of  a  quorum,  a  majority  of  the  shares
represented  in person or by proxy may adjourn the meeting from time to time not
exceeding  a total of sixty  (60) days  without  further  notice  other  than by
announcement at such meeting.  At such adjourned meeting at which a quorum shall
be present,  any business may be transacted  which might have been transacted at
the meeting  originally  called.  The  stockholders  present at a duly organized
meeting may continue to transact business until adjournment, notwithstanding the
withdrawal of enough stockholders to leave less than a quorum. In the event that
at any meeting a quorum exists for the transaction of some business but does not
exist for the transaction of other  business,  the business as to which a quorum
is present may be  transacted  by the  holders of stock  present in person or by
proxy who are entitled to vote thereon.

Section 5.        VOTING

                  Each  share of  common  stock  will be  entitled  to one vote,
unless the Charter of the Corporation provides for a greater or lesser number of
votes per share or limits or denies voting rights.

Section 6.        PROXIES

                  At all meetings of  stockholders,  a stockholder  may vote the
shares  owned of record by him either in person of by proxy  executed in writing
by the stockholder or by his duly authorized attorney-in-fact.  Such proxy shall
be filed  with the  Secretary  of the  Corporation  before or at the time of the
meeting.  No proxy shall be valid after  eleven (11) months from the date of its
execution, unless otherwise provided in the proxy.

Section 7.        PLACE OF MEETING

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                  The Board of Directors may designate any place,  either within
or without  the State of  Maryland,  as the place of  meeting  for any annual or
special meeting of stockholders.

Section 8.        CONDUCT OF MEETINGS

                  Meetings  of  stockholders  shall  be  presided  over  by  the
Chairman  of the Board,  if one be elected  and is present at the meeting or, if
not, by the  President of the  Corporation  or, if he is not present,  by a Vice
President of the Corporation or, if he is not present, by a Vice President,  or,
if no Vice President is present, by a chairman to be elected at the meeting. The
Secretary of the Corporation,  or if he is not present, any Assistant Secretary,
shall act as secretary of such meetings. In the absence of the Secretary and any
Assistant  Secretary,  the  presiding  officer  may  appoint  a person to act as
secretary of the meeting.

Section 9.        INFORMAL ACTION BY STOCKHOLDERS

                  Any action  required or  permitted to be taken at a meeting of
stockholders  may be taken  without a meeting if there is filed with the records
of  stockholders'  meetings a  unanimous  written  consent  which sets forth the
action and is signed by each  stockholder  entitled  to vote on the matter and a
written  waiver of any right to dissent signed by each  stockholder  entitled to
notice of the meeting but not entitled to vote at it.


                                   ARTICLE II.
                                    DIRECTORS

Section 1.        POWERS

                  The business and affairs of the  Corporation  shall be managed
by its  Board  of  Directors,  which  may  exercise  all of  the  powers  of the
Corporation,  except such as are by statute,  by the Charter of the Corporation,
or by these By-Laws expressly conferred upon or reserved to the stockholders.

Section 2.        NUMBER AND TENURE


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                  The number of Directors  shall be three (3),  which number may
be altered by a majority  of the entire  Board of  Directors,  provided  that it
shall never be less than three (3) nor more than nine (9). Each  Director  shall
hold office until the next annual meeting of stockholders or until his successor
shall have been elected and shall have qualified. The number of Directors may be
increased or decreased by the affirmative bote of not less than two-thirds (2/3)
of the entire  Board of  Directors,  but the action may not affect the tenure of
office of any Director.

Section 3.        VACANCIES

                  Any vacancy  occurring in the Board of  Directors,  other than
one occurring  because of an increase in the number of Directors,  may be filled
by the affirmative  bote of a majority of the remaining  Directors.  Any vacancy
occurring  in the  Board  of  Directors  due to an  increase  in the  number  of
Directors  may be filled by a  majority  of the  entire  Board of  Directors.  A
Director  elected to fill a vacancy shall serve until the next annual meeting of
stockholders and until his successor is elected and qualifies.

Section 4.        REGULAR MEETING

                  The  Board  of  Directors   shall  meet  for  the  purpose  of
organization, the election of Officers, and the transaction of other business as
soon as  practicable  after each annual meeting of  stockholders.  Other regular
meetings of the Board of Directors  shall be held at such times and such places,
either within or without the State of Maryland,  as may be designated  from time
to time by the Board of Directors.

Section 5.        SPECIAL MEETING

                  Special  meetings of the Board of  Directors  may be called by
the President or by any two Directors.  The person or persons authorized to call
special  meetings of the Board of Directors  may fix any time and place,  either
within or without the State of  Maryland,  as the time and place for holding the
special meeting of the Board of Directors called by them.

Section 6.        NOTICE

                  Notice of every regular or special  meeting of the Board shall
be given to each  Director by written  notice  stating the time and place of the

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meeting.  Notice is given to a Director when it is delivered  personally to him,
left at his residence of usual place of business, or sent by telegraph, at least
twenty-four (24) hours before the time of the meeting or, in the alternative, be
mailed to his address as it appears on the records of the  Corporation  at least
seventy-two  (72) hours before the time of the  meeting.  Any Director may waive
notice of any meeting by written  waiver  filed with the records of the meeting,
either before or after the holding  thereof.  The  attendance of a Director at a
meeting  shall  constitute  a waiver of notice of such  meeting,  except where a
Director  attends  a  meeting  for  the  express  purpose  of  objecting  to the
transaction  of any  business  because  the  meeting is not  lawfully  called or
convened.  Neither  the  business to be  transacted  at, nor the purpose of, any
regular or special  meeting of the Board of  Directors  need be specified in the
notice or waiver of notice of such meeting.

Section 7.        QUORUM

                  Unless  otherwise  provided by statute,  by the Charter of the
Corporation,  or by these  By-Laws,  a majority of the Board of Directors  shall
constitute  a quorum  for the  transaction  of  business,  but if less than such
quorum is present at a meeting,  a majority of the Directors present may adjourn
the meeting from time to time without further notice.

Section 8.        MANNER OF ACTING

                  The action of a majority of the Directors present at a meeting
at which a quorum is  present  shall be the  action  of the  Board of  Directors
unless the  concurrence  of a greater  proportion is required for such action by
statute, by the Charter of the Corporation, or by these By-Laws.

Section 9.        COMPENSATION

                  By  resolution  of the  Board  of  Directors  a fixed  sum and
expenses of  attendance,  if any, may be paid to the Directors for attendance at
meetings of the Board of Directors or of committees thereof.  Other compensation
for their  services as such or on  committees of the Board of Directors may also
be paid to Directors.  No such payment shall  preclude any Director from serving
the Corporation in any other capacity and receiving compensation therefor.

Section 10.       INFORMAL ACTION

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                  Any action required or permitted to be taken at any meeting of
the Board of Directors  may be taken  without a meeting if a written  consent to
such action is signed by all members of the Board of Directors  and such written
consent is filed with the minutes of proceedings of the Board of Directors.

Section 11.       MEETING BY CONFERENCE TELEPHONE

                  Members of the Board of Directors may participate in a meeting
by means of a conference  telephone or similar  communications  equipment if all
persons  participating  in the  meeting  can hear each  other at the same  time.
Participating  in a meeting by these means  constitutes  presence in person at a
meeting.


                                  ARTICLE III.
                                   COMMITTEES

Section 1.        COMMITTEES

                  The Board of  Directors  may appoint from among its members an
Executive  Committee and other committees  composed of two or more Directors and
delegate to these  committees in the intervals  between meetings of the Board of
Directors  any of the  powers of the  Board of  Directors,  except  the power to
declare dividends or distributions on stock approve any merger or share exchange
which does not require  stockholder  approval,  amend the  By-Laws,  issue stock
other than as permitted by statute,  or recommend to the stockholders any action
which requires stockholder  approval.  Each committee may fix rules of procedure
for its business.  A majority of the members of a committee  shall  constitute a
quorum  for the  transaction  of  business  and the act of a  majority  od those
present  at a  meeting  at which a  quorum  is  present  shall be the act of the
committee.  The members of a committee  present at any  meeting,  whether or not
they  constitute  a quorum,  may appoint a Director to act in place of an absent
member. The members of a committee may conduct any meeting thereof by conference
telephone in accordance with the provisions of Article II, Section 11.

Section 2.        MINUTES

                  Each  committee  shall  keep  minutes of its  proceedings  and
report the same to the Board of Directors as and when required by the Board.

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Section 3.        EMERGENCY

                  In the event of a state of disaster of sufficient  severity to
prevent  the  conduct  and  management  of  the  affairs  and  business  of  the
Corporation under the direction of its Directors and Officers as contemplated by
its Charter and By-Laws, any two or more available members of the then incumbent
Executive  Committee  shall  constitute a quorum of that  Committee for the full
conduct  and  management  of the  affairs and  business  of the  Corporation  in
accordance  with the  provisions of Article III,  Section 1. In the event of the
unavailability,  at such time, of a minimum of two members of the then incumbent
Executive Committee,  the available directors shall elect an Executive Committee
consisting of any two members of the Board of Directors,  whether or not they be
Officers of the  Corporation,  which two members shall  constitute the Executive
Committee for the full conduct and management of the affairs of the  Corporation
in  accordance  with the  foregoing  provisions  of this Section 3. This Section
shall be subject  to  implementation  by  resolution  of the Board of  Directors
passed from time to time for that  purpose,  and any  provisions  of the By-Laws
(other  than this  Section  3) and any  resolutions  which are  contrary  to the
provisions  of this  Section  3 or to the  provisions  of any such  implementary
resolutions  shall be  suspended  until it shall be  determined  by any  interim
Executive  Committee  acting  under  this  Section  3 that  it  shall  be to the
advantage of the Corporation to resume the conduct and management of its affairs
and business under all the other provisions of the By-Laws.


                                   ARTICLE IV.
                                    OFFICERS

Section 1.        EXECUTIVE OFFICERS

                  The  Corporation  shall  have  a  President,  who  shall  be a
Director of the Corporation,  a Secretary,  and a Treasurer.  It may also have a
Chairman of the Board, who shall be a Director of the  Corporation,  one or more
Vice Presidents,  one or more Assistant Vice  Presidents,  one or more Assistant
Secretaries,  one or more Assistant  Treasurers,  and such other officers as the
Board of  Directors  may elect.  Any two offices may be held by the same person,
except those of President  and Vice  President,  but no Officer  shall  execute,
acknowledge  or  verify  any  instrument  in  more  than  one  capacity  if such
instrument  is required to be executed,  acknowledged  or verified by any two or
more Officers.

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Section 2.        ELECTION AND TENURE

                  The Officers of the Corporation  shall be elected by the Board
of  Directors  at the first  meeting of the Board of  Directors  held after each
annual meeting of the  stockholders,  or as soon after such first meeting as may
be convenient. Each Officer shall hold office for such period, not to exceed one
(1) year, as the Board of Directors  may fix or until his  successor  shall have
been duly elected and shall have qualified.

                  The Board of  Directors  may,  at any  time,  and from time to
time,  authorize the making or adoption by the Corporation of special  contracts
with an Officer  for  services of such  Officer  for a fixed  period and on such
terms and conditions,  and with such powers, duties and compensation,  as may be
fixed by such  contract,  and may  elect  such  Officer  for such term or terms,
whether exceeding one (1) year or not, as may be specified by such contract.

Section 3.        REMOVAL

                  Any Officer or agent of the  Corporation may be removed by the
Board  of  Directors  whenever,  in its  judgment,  the  best  interests  of the
Corporation will be served thereby,  but such removal shall be without prejudice
to the contract rights, if any, of the person so removed.

Section 4.        VACANCIES

                  A  vacancy  in any  office  may be  filled  by  the  Board  of
Directors for the unexpired portion of the term.

Section 5.        CHAIRMAN OF THE BOARD

                  The Chairman of the Board, if one be elected, shall preside at
all meetings of the Board of Directors and of the stockholders at which he shall
be present.  He shall have and may  exercise  such  powers as are,  from time to
time, assigned to him by the Board of Directors.

Section 6.        PRESIDENT


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                  The President shall be elected from the Board of Directors and
shall,  in the absence of the Chairman of the Board,  preside at all meetings of
the Board and of the stockholders at which he is present.  He shall be the chief
executive  office of the Corporation and, subject to the control of the Board of
Directors,  shall, in general,  supervise and administer all of the business and
affairs of the Corporation.  In general, the President shall have all powers and
shall  perform all duties  incident to the office of  President  and such as may
from time to time be prescribed by the Board of Directors.

Section 7.        VICE PRESIDENTS

                  The Vice President or Vice  Presidents,  at the request of the
President or in his absence or during his  inability to act,  shall  perform the
duties and exercise the  functions  of the  President,  and when so acting shall
have the powers of the President. If there be more than one Vice President,  the
Board of Directors may determine which one or more of the Vice Presidents  shall
perform  any of  such  duties  or  exercise  any of such  functions,  or if such
determination is not made by the Board of Directors, the President may make such
determination;  otherwise  any of the Vice  Presidents  may  perform any of such
duties,  and have such  additional  descriptive  designations  (if any) in their
titles as may be assigned by the Board of Directors or the President.

Section 8.        THE SECRETARY

                  The Secretary shall in general have all powers and perform all
duties  incident to the office of Secretary and such as may from time to time be
prescribed by the Board of Directors or by the President.

Section 9.        THE TREASURER

                  The  Treasurer  shall  have  general  charge of the  financial
affairs of the Corporation.  He shall in general have all powers and perform all
duties  incident to the office of Treasurer and such as may from time to time be
prescribed by the Board of Directors or by the President.

Section 10.       ASSISTANT OFFICERS

                  The Assistant  Vice Presidents  shall have such  duties as may
from  time  to  time be  assigned to  them by  the Board  of  Directors  or  the


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President.  The Assistant Secretaries shall have such duties as may from time to
time be  assigned  to them by the  Board  of  Directors  or the  Secretary.  The
Assistant Treasurers shall have such duties as may from time to time be assigned
to them by the Board of Directors of the Treasurer.

Section 11.       OTHER OFFICERS

                  Such  other  officers  as  may be  elected  by  the  Board  of
Directors  shall have such powers and perform  such duties as the Board may from
time to time prescribe.

Section 12.       SALARIES

                  The salaries of the Officers  shall be fixed from time to time
by the Board of Directors, and no Officer shall be prevented from receiving such
salary by reason of the fact that he is also a Director of the Corporation.

Section 13.       SPECIAL APPOINTMENTS

                  In the absence or incapacity  of any Officer,  or in the event
of a vacancy in any office,  the Board of Directors  may designate any person to
fill any such office pro tempore or for any particular purpose.


                                   ARTICLE V.
                                      SEAL

                  The seal of the Corporation shall be circular in form with the
words  "CHEUNG  LABORATORIES,  INC." in the  periphery and the words and figures
"INCORPORATED 1982 MARYLAND" in the center.


                                   ARTICLE VI.
                                      STOCK

Section 1.        CERTIFICATES OF STOCK

                  Certificates representing shares of the Corporation shall   be
in such form as shall be determined by the Board of Directors.  Each certificate
shall be signed,

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manually or by facsimile, by the President or a Vice President and countersigned
by the Secretary or the Treasurer and shall be sealed with the corporate seal or
a facsimile of it. All certificates  surrendered to the Corporation for transfer
shall be  cancelled,  and no new  certificates  shall be issued until the former
certificate  for a like  number  of  shares  shall  have  been  surrendered  and
cancelled,  except  that  in  case of a lost,  stolen,  destroyed  or  mutilated
certificate,  a new one may be issued  therefor upon such terms and indemnity to
the Corporation as the Board of Directors may prescribe.

Section 2.        TRANSFER OF SHARES

                  Transfer  of shares of the  Corporation  shall be made only on
its stock  transfer  books by the holder of record  thereof,  or by his attorney
thereunto  authorized  by power of  attorney  duly  executed  and filed with the
Secretary  of  the  Corporation,  and  on  surrender  for  cancellation  of  the
certificate for such shares.  The person in whose name shares stand on the books
of the Corporation shall be deemed to be the owner thereof for all purposes. The
Board of Directors  shall have power and  authority to make such other rules and
regulations  as it may deem  necessary  or  appropriate  concerning  the  issue,
transfer and  registration of certificates  of stock;  and may appoint  transfer
agents and registrars thereof. The duties of transfer agent and registrar may be
combined.

Section 3.        FIXING DATE FOR DETERMINATION OF STOCKHOLDERS'
RIGHTS

                  The Board of  Directors  may fix,  in  advance,  a date as the
record date for the purpose of determining the  stockholders  entitled to notice
of, or to vote at, any meeting of stockholders,  or the stockholders entitled to
receive  payment of any dividend or the allotment of any rights,  or in order to
make a  determination  of  stockholders  for  any  other  proper  purpose.  Only
stockholders  of record on such date shall be entitled to notice of, and to vote
at, such  meeting or to receive such  dividends  or rights,  as the case may be,
notwithstanding  any transfer of any stock on the books of the Corporation after
such record date fixed as aforesaid.



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                                  ARTICLE VII.
                                   AMENDMENTS

                  The  By-Laws  may be  altered,  amended or  repealed,  and new
By-Laws may be adopted, by a majority of the entire Board of Directors.


                                  ARTICLE VIII.
                                   FISCAL YEAR

                  The fiscal year of the  Corporation  shall end on September 30
of each year.


                                   ARTICLE IX.
                                 INDEMNIFICATION

Section 1.        DEFINITIONS

                  As used in this  Article  IX,  any  word or words  defined  in
Section 2-418 of the Corporations and Associations Article of the Annotated Code
of Maryland, as amended from time to time (the "Indemnification Section"), shall
have the same meaning as provided in the Indemnification Section.

Section 2.        DIRECTORS AND OFFICERS

                  The  Corporation  shall  indemnify  and advance  expenses to a
Director or Officer of the  Corporation  in connection  with a proceeding to the
fullest extent permitted by and in accordance with the Indemnification Section.

Section 3.        OTHER EMPLOYEES AND AGENTS

                  With respect to an employee or agent, other than a Director of
Officer, of the Corporation,  the Corporation may, as determined by the Board of
Directors of the Corporation, indemnify and advance expenses to such employee or
agent  in  connection  with a  proceeding  to  the  extent  permitted  by and in
accordance with the Indemnification Section.


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                                   ARTICLE X.
                                WAIVER OF NOTICE

                  Unless  otherwise  provided  by law,  whenever  any  notice is
required to be given to any stockholder or director of the Corporation under the
provisions  of  these  ByLaws  or  under  the  provisions  of  the  Articles  of
Incorporation,  a waiver  thereof  in  writing,  sighed by the person or persons
entitled to such notice,  whether before of after the time stated therein, shall
be deemed equivalent to the giving of such notice.



                                   ARTICLE XI.
                                   AMENDMENTS

                  These  By-Laws  may be altered,  amended or  repealed  and new
By-Laws may be adopted by a vote of the stockholders  representing a majority of
all shares issued and outstanding, at any annual stockholders' meeting or at any
special  stockholders'  meeting when the proposed  amendment has been set out in
the notice of such meeting.



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