THE SECURITIES  REPRESENTED BY THIS  CERTIFICATE MAY NOT BE OFFERED FOR
         SALE,  SOLD OR OTHERWISE  TRANSFERRED  EXCEPT  PURSUANT TO AN EFFECTIVE
         REGISTRATION  STATEMENT  MADE  UNDER  THE  SECURITIES  ACT OF 1933 (THE
         "ACT"), OR PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE ACT.

                                                   Warrant Certificate No.:_____
                                                   Date of Issue:____________

Void after 5:00 p.m, Columbia, Maryland Time on_________

                               Warrant to Purchase
                             __________Common Shares

                        WARRANT TO PURCHASE COMMON SHARES

                            CHEUNG LABORATORIES, INC.

This is to certify that, for value received,

                            DunnHughes Holdings, Inc.
                            -------------------------

or  registered  assigns  ("Holder"),  is  entitled  to  purchase  subject to the
provisions  of  this  Warrant,  from  Cheung  Laboratories,   Inc.,  a  Maryland
corporation  ("Company"),  at any time  after_________  and not later  than 5:00
p.m.,  Columbia,  Maryland Time,  on__________,  shares, $0.01 par value, of the
Company Common Stock ("Common Stock"), at the purchase price per share of $____.
The number of shares of Common  Stock to be received  upon the  exercise of this
Warrant  and the  price to be paid for a share of Common  Stock may be  adjusted
from  time to time  as  hereinafter  set  forth.  The  shares  of  Common  Stock
deliverable  upon  such  exercise,  and as  adjusted  from  time  to  time,  are
hereinafter sometimes referred to as "Warrant Stock" and the exercise price of a
share of Common Stock in effect at any time and as adjusted from time to time is
hereinafter sometimes referred to as the "Exercise Price."

              (a) Exercise of Warrant. This Warrant may be exercised in whole or
in part at any time or from  time to time on or after the date  hereof,  but not
later than 5:00 p.m.,  Columbia,  Maryland Time, on the date set forth above. If
such date is a day on which banking institutions are authorized by law to close,
then the expiration  date shall be on the next succeeding day which shall not be
such a day. This Warrant may be exercised by presentation  and surrender  hereof
to the  Company  or at the  office of its stock  transfer  agent,  if any,  with
written  notice  duly  executed  and  accompanied  by  payment  in  cash or cash
equivalent  of the  Exercise  Price for the number of shares  specified  in such
notice, together with all federal and state taxes applicable upon such exercise.
If this  Warrant  should be  exercised  in part only,  the Company  shall,  upon
surrender  of this Warrant for  cancellation,  execute and deliver a new Warrant
evidencing  the right of the  holder  to  purchase  the  balance  of the  shares
purchasable hereunder. Upon receipt by the Company of this Warrant at the office
or agency of the  Company,  in proper  form for  exercise,  the Holder  shall be
deemed to be the holder of record of the shares of Common  Stock  issuable  upon
such  exercise,  notwithstanding  that the stock  transfer  books of the Company
shall then be closed or that  certificates  representing  such  shares of Common
Stock  shall  not  then  be  actually  delivered  to the  Holder.  The  Form  of
Subscription  Agreement,  attached  hereto,  shall be  submitted  at the time of
exercise and all other documents reasonably requested.


                                        1



              (b)  Reservation of Shares.  The Company hereby agrees that at all
times there shall be reserved for issuance and/or delivery upon exercise of this
Warrant  such  number of shares of its  Common  Stock as shall be  required  for
issuance or delivery upon exercise of this Warrant.

              (c) Restrictions on Transfer.  The securities  represented  hereby
and the shares to be issued on exercise have not been  registered  under federal
or  state  securities  laws.  They  may not be sold or  offered  for sale in the
absence of effective  registration  under such securities laws, or an opinion of
counsel satisfactory to the Company that such registration is not required.

              (d)  Exchange,  Assignment  or Loss of  Warrant.  This  Warrant is
exchangeable,  without expense,  at the option of the Holder,  upon presentation
and  surrender  hereof to the  Company  or at the  office of its stock  transfer
agent,  if any, for other  Warrants of  different  denominations  entitling  the
holder  thereof to purchase in the aggregate the same number of shares of Common
Stock  purchasable  hereunder.  Subject to compliance  with  paragraph (d), this
Warrant is assignable.  Any such  assignment  shall be made by surrender of this
Warrant to the  Company or at the office of its stock  transfer  agent,  if any,
with written notice of assignment duly executed and funds  sufficient to pay any
transfer tax; whereupon the Company shall, without charge, execute and deliver a
new Warrant in the name of the assignee  named in such  instrument of assignment
and this  Warrant  shall  promptly be  canceled.  This Warrant may be divided or
combined  with other  Warrants  which carry the same  rights  upon  presentation
hereof  at the  office of the  Company  or at the  office of its stock  transfer
agent,  if  any,  together  with a  written  notice  specifying  the  names  and
denominations  in which new  Warrants  are to be issued and signed by the Holder
hereof.  The term  "Warrant"  as used  herein  includes  any  Warrant  issued in
substitution for or replacement of this Warrant,  or into which this Warrant may
be divided or exchanged and the term "original issue date hereof" shall refer to
the  date  that the  Company  first  issued a  Warrant  which  was  subsequently
transferred  or exchanged  for another.  Upon receipt by the Company of evidence
satisfactory  to it of the  loss,  theft,  destruction  or  mutilation  of  this
Warrant,  and  (in  the  case of  loss,  theft  or  destruction)  of  reasonably
satisfactory  indemnification,  and  upon  surrender  and  cancellation  of this
Warrant,  if  mutilated,  the Company  will execute and deliver a new Warrant of
like  tenor  and  date.  Any such  new  Warrant  executed  and  delivered  shall
constitute  an  additional  contractual  obligation  on the part of the  Company
whether or not this Warrant so lost, stolen, destroyed, or mutilated shall be at
any time enforceable by anyone.

              (e) Rights of the Holder.  The Holder shall not, by virtue hereof,
be  entitled  to any rights of a  shareholder  in the  Company  either at law or
equity,  and the  rights of the Holder are  limited  to those  expressed  in the
Warrant and are not  enforceable  against  the Company  except to the extent set
forth herein.

              (f) Split or Combination of Stock and Stock Dividend:  In case the
Company  shall at any time  subdivide  its  outstanding  shares of Stock  into a
greater  number of shares or declare a dividend upon its Stock payable solely in
shares of Stock,  the Stock Purchase Price in effect  immediately  prior to such
subdivision or declaration  shall be proportionally  reduced,  and the number of
shares issuable upon exercise of the Option shall be proportionately  increased.
Conversely,  in case the  outstanding  shares of Stock of the  Company  shall be
combined into a smaller  number of shares,  the Stock  Purchase  Price in effect
immediately prior to such combination shall be  proportionately  increased,  and
the  number  of  shares   issuable   upon   exercise  of  the  Option  shall  be
proportionately reduced.

              (g) Officer's  Certificate.  Whenever the Exercise  Price shall be
adjusted as required by the provisions of Section (f) hereof,  the Company shall
forthwith file in the custody of its Secretary or an Assistant  Secretary at its
principal  office,  and with its stock  transfer  agent,  if any,  an  officer's

                                        2



certificate  showing the adjusted  Exercise Price  determined as herein provided
and setting forth in reasonable detail the facts requiring such adjustment. Each
such officer's  certificate  shall be made available at all reasonable times for
inspection  by the  Holder  and the  Company  shall,  forthwith  after each such
adjustment,  deliver a copy of such certificate to the Holder.  Such certificate
shall be conclusive as to the correctness of such adjustment.

              (h) Notice to Warrant  Holders.  So long as this Warrant  shall be
outstanding  and  unexercised  (i) if the Company shall pay any dividend or make
any distribution upon the Common Stock or (ii) if the Company shall offer to the
holders of Common Stock for subscription or purchase by them any shares of stock
of any class or any other rights or (iii) if any capital  reorganization  of the
Company,  reclassification of the capital stock of the Company, consolidation or
merger of the Company with or into another corporation,  sale, lease or transfer
of all or substantially all of the property and assets of the Company to another
corporation, or voluntary or involuntary dissolution,  liquidation or winding up
of the Company  shall be effected,  then,  in any such case,  the Company  shall
cause to be  delivered  to the Holder,  at least ten (10) days prior to the date
specified in (x) or (y) below,  as the case may be, a notice  containing a brief
description of the proposed action and stating the date on which (x) a record is
to be taken for the purpose of such  dividend,  distribution  or rights,  or (y)
such reclassification, reorganization, consolidation, merger, conveyance, lease,
dissolution, liquidation or winding up is to take place and the date, if any, is
to be fixed, as of which the 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,  reorganization,  consolidation, merger,
conveyance, dissolution, liquidation or winding up.

              (i)  Reclassification,  Reorganization  or Merger.  In case of any
reclassification,  capital  reorganization or other change of outstanding shares
of Common  Stock of the Company  (other than a change in par value,  or from par
value to no par  value or from no par value to par  value,  or as a result of an
issuance  of  Common  Stock by way of  dividend  or other  distribution  or of a
subdivision or  combination),  or in case of any  consolidation or merger of the
Company  with or into  another  corporation  (other  than a merger  in which the
Company  is  the  continuing  corporation  and  which  does  not  result  in any
reclassification,  capital  reorganization or other change of outstanding shares
of Common Stock of the class  issuable upon exercise of this Warrant) or in case
of any sale or conveyance to another  corporation of the property of the Company
as an  entirety  or  substantially  as an  entirety,  the  Company  shall  cause
effective  provision  to be  made  so that  the  holder  shall  have  the  right
thereafter,  by  exercising  this  Warrant,  to purchase  the kind and amount of
shares  of  stock  and  other  securities  and  property  receivable  upon  such
reclassification, capital reorganization or other change, consolidation, merger,
sale or conveyance.  Any such provision shall include provisions for adjustments
which shall be as nearly  equivalent as may be  practicable  to the  adjustments
provided for in this Warrant.

              (j) Piggy-back/Incidental  Registration If at any time the Company
subsequent  to the next  public  offering  of  registered  Common  Shares of the
Company,  shall propose the filing of a Registration Statement on an appropriate
form under the  Securities  Act for the  registration  of any  securities of the
Company,  other  than  a  registration  statement  on  Form  S-4  or  S-8 or any
equivalent form of registration statement then in effect, then the Company shall
give the Holder(s) notice of such proposed registration and shall include in any
Registration  Statement  relating  to such  securities  all or a portion  of the
Warrant Stock then owned or to be owned by such Holder(s),  which such Holder(s)
shall request (such  Holder(s) to be considered  "Selling  Shareholder(s)"),  by
notice given by such Selling  Shareholder(s)  to the Company  within 15 business
days after the giving of such notice by the  Company,  within 15  business  days
after the giving of such notice by the Company, to be so included.  In the event

                                        3



of the  inclusion  of Warrant  Stock  pursuant to this  paragraph k, the Company
shall bear the Costs and Expenses of such registration;  provided,  however that
the Selling  Shareholder(s)  shall pay the fees and  disbursements  of their own
counsel and,  pro-rata based upon the number of shares of Warrant Stock included
therein as these  relate to the total  number of Common  Shares to be offered or
sold,  the  Securities  Act  registration  fees and  underwriters  discounts and
compensation  attributable  to the inclusion of such Warrant  Stock.  Nothing in
this  paragraph  k  shall  require  the  registration  of  Warrant  Stock  in  a
Registration  Statement  relating  solely to (a)  securities to be issued by the
Company in connection with the acquisition of the stock or the assets of another
corporation,  or the merger or consolidation of any other corporation by or with
the  Company  or  any  of  its  subsidiaries,  or an  exchange  offer  with  any
corporation,  (b) securities to be offered to the then existing security holders
of the Company,  or (c) securities to be offered to employees of the Company. In
the  event  the   distribution  of  securities  of  the  Company  covered  by  a
Registration  Statement  referred to in this paragraph k is to be  underwritten,
then the Company's  obligation to include  Warrant Stock in such a  Registration
Statement  shall be  subject,  at the option of the  Company,  to the  following
further conditions:

                       (1) The  distribution  for  the  account  of the  Selling
         Shareholders  shall be  underwritten by the same  underwriters  who are
         underwriting  the distribution of the securities for the account of the
         Company  and/or any other persons whose  securities are covered by such
         Registration  Statement and the Selling Shareholder(s) shall enter into
         an agreement with such underwriters containing customary provisions.

                       (2) If  the  Selling  Shareholders  are  included  in the
         Registration  Statement and if the underwriting  agreement entered into
         with the aforesaid  underwriters contains restrictions upon the sale of
         securities of the Company,  other than the  securities  which are to be
         included in the proposed  distribution,  for a period not  exceeding 90
         days from the effective date of the Registration  Statement,  then such
         restrictions  shall be binding  upon the  Selling  Shareholder(s)  with
         respect to any Warrant Stock not covered by the Registration  Statement
         and, if requested by the underwriter,  the Selling Shareholder(s) shall
         enter into a written agreement to that effect.

                        (3) If the underwriters shall state in writing that they
         are  unwilling  to  include  any or all of the  Selling  Shareholder(s)
         Warrant Stock in the proposed underwriting because such inclusion would
         materially  interfere  with the orderly  sale and  distribution  of the
         securities being offered by the Company, then the number of the Selling
         Shareholder(s)' shares of Warrant Stock to be included shall be reduced
         pro  rata on the  basis  of the  number  of  shares  of  Warrant  Stock
         originally requested to be included by such Selling Shareholder(s),  or
         there shall be no inclusion of the shares of the Selling Shareholder(s)
         in the Registration Statement not proposed distribution,  in accordance
         with such statement by the underwriters.

              (k)  Applicable  Law.  This  Warrant  shall be  governed  by,  and
construed in accordance with, the laws of the State of Maryland.


                                        4



              (l) Optional Waiver. Holder may waive by signed writing any rights
of Holder contained herein.

              (m) IN ADDITION TO THE RESTRICTIONS ON  TRANSFERABILITY  DESCRIBED
HEREIN,  THE SECURITIES  ISSUABLE ON EXERCISE OF THIS WARRANT SHALL NOT BE SOLD,
PLEDGED, TRANSFERRED,  HYPOTHECATED OR ASSIGNED WITHIN 7 DAYS BEFORE OR 180 DAYS
AFTER THE DATE OF EFFECTIVENESS OF A REGISTRATION STATEMENT FILED BY THE COMPANY
WITH THE SECURITIES AND EXCHANGE COMMISSION IN CONNECTION WITH A PUBLIC OFFERING
OF THE COMPANY'S SECURITIES.  THIS RESTRICTION IS IN ADDITION TO AND NOT IN LIEU
OF THE RESTRICTIONS CONTAINED HEREIN AND AS SUCH, THIS 180 DAY PERIOD MAY EXPIRE
PRIOR TO OR BEYOND THE  RESTRICTIONS  IMPOSED  HEREIN.  THIS  RESTRICTION  SHALL
OBLIGATE  ALL   SUCCESSORS  IN  INTEREST  TO  THE  SHARES  ISSUED  ON  EXERCISE.
CERTIFICATES  REPRESENTING THE WARRANT STOCK SHALL BEAR A LEGEND EVIDENCING THIS
RESTRICTION.

Executed as of the date first above written.

                                                     CHEUNG LABORATORIES, INC.



                                                   By:__________________________
                                                      Augustine Cheung, Chairman

Attest:


- -----------------
Secretary


                                        5



                                  EXERCISE FORM

                          To be executed by the Holder
                          in Order to Exercise Warrants


The undersigned Holder hereby irrevocably elects to exercise __________ Warrants
represented by this Warrant Agreement,  and to purchase the securities  issuable
upon the exercise of such  Warrants,  and requests  that  certificates  for such
securities shall be issued in the Holder's name and be delivered to

                    ----------------------------------------
                    ----------------------------------------
                    ----------------------------------------
                    ----------------------------------------
                         [please print or type address]

and if such number of Warrants  shall not be all the Warrants  evidenced by this
Warrant Agreement, that a new Warrant Agreement for the balance of such Warrants
be registered in the name of, and delivered to, the Holder at the address stated
above.

The undersigned  acknowledges  that the  Warrant  Shares issued on exercise will
    be "restricted securities" and will bear appropriate restrictive legends.

         Dated: _______________________________________________________
                               Signature of Holder


                         ------------------------------

                         ------------------------------
                               Taxpayer ID Number


                         ------------------------------
                              Signature Guaranteed

                         ------------------------------


                                        6