THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE
                 SECURITIES ACT OF 1933 OR UNDER THE SECURITIES
                     LAW OF ANY STATE AND MAY NOT BE SOLD OR
                  TRANSFERRED UNLESS REGISTERED UNDER THAT ACT
                    AND ANY APPLICABLE STATE SECURITIES LAWS
                 OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE.

                            CHEUNG LABORATORIES, INC.
                       8% SENIOR SECURED CONVERTIBLE NOTE
                                             
                                                             Baltimore, Maryland
                                                                  July ___, 1996
         FOR VALUE RECEIVED,  CHEUNG LABORATORIES,  INC., a Maryland corporation
(the  "Corporation")  promises  to  pay  to  __________________,  or  registered
assigns, (the "Holder") the principal amount of ________________________ Dollars
($________)  (the  "Principal  Amount") on or before  December  31,  1997,  with
accrued  interest as provided  below,  all  subject to the  following  terms and
conditions.

         Interest  (computed  on the  basis of a 360-day  year of twelve  30-day
months) on the unpaid  Principal Amount shall accrue at the rate of 8% per annum
from the date hereof.

         All payments of  principal  of and  interest on this 8% Senior  Secured
Convertible  Note (the "Note") are secured  pursuant to a Loan Agreement,  and a
Pledge  Agreement,  both dated July 1, 1996 which apply to this series of bridge
financing  notes  (the  "Notes"),  and shall be made in  currency  of the United
States of America as at the time of payment shall be legal tender for payment of
public  and  private  debts.  Should an Event of  Default  occur  under the Loan
Agreement, this Note shall be accelerated and be immediately due and payable

         This Note and the Notes shall be senior  indebtedness of CLI and have a
priority over payment of any other  indebtedness of CLI, such other indebtedness
of CLI to be repaid only after the full repayment of the Principal  Amount,  and
accrued  interest,  due  hereunder  and under the other  Notes.  This Note shall
mature and the entire  Principal Amount thereof and all accrued interest thereon
shall become due and payable on December 31, 1997;  provided that, at the option
of the Holder this Note may be paid by the Holder electing:

         A.  To be  repaid  from  the  proceeds  of a  private  offering  by the
Corporation,  or a series of private  offerings,  which aggregate  $8,000,000.00
(U.S.)  or more  prior  to  December  31,  1997,  and  involve  the  sale of the
Corporation's common stock,  preferred stock,  long-term debt,  convertible debt
(other than this Note), or other similar  security or financial  instrument (the
"Private Offering"); or


318350.002(B&F)                                                         12/10/96
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         B. On the date of  maturity  to convert  the  Principal  Amount and any
unpaid  accrued  interest  into common stock of the  Corporation.  If the Holder
shall elect to so convert the Note,  the number of shares of common  stock to be
received by the Holder shall be the greater of:

                  (i)      the number of shares determined by pricing the common
                           stock  of  the   Corporation   at  $.41   per   share
                           (representing  the closing  price of the common stock
                           of the  Corporation  as quoted  on  NASDAQ  (Bulletin
                           Board) on May 31, 1996); or

                  (ii)     the  lowest  price  per  share  in the  Corporation's
                           Private   Offering   on  the  same   terms  as  other
                           participants  in such  Private  Offering (on a common
                           stock  equivalency  basis if the Private  Offering is
                           other than common stock).

         If any  payment  of  interest  is not made on the date when due for any
reason,  or the  Principal  Amount  shall not be paid when  payable,  whether at
maturity or by  acceleration  or otherwise,  interest shall accrue on any amount
overdue more than 30 days at a rate equal to 18% per annum  (computed based on a
360-day year applied to twelve 30-day  months) until such overdue amount is paid
in full.

         This Note shall be governed by and  construed  in  accordance  with the
internal laws of the State of Maryland.

         IN WITNESS WHEREOF,  Cheung  Laboratories,  Inc. has executed this Note
under seal as of the date and year first above written.

                                          CHEUNG LABORATORIES, INC.


                                    By:   ___________________________
                                          Dr. Augustine Y. Cheung, President
[CORPORATE SEAL]

Attest

_____________________________
Secretary:
c:\wpwin\bridgcli\convnot.8%


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