PROMISSORY NOTE

         FOR VALUE RECEIVED,  Cheung  Laboratories,  Inc. (the "Company") hereby
ratifies  and confirms its promise of January 26, 1987 to pay to the order of of
Augustine Y. Cheung,  the sum of Seventy-Eight  Thousand Seven Hundred and Fifty
And 00/100 ($78,750.00)  Dollars,  together with interest thereon at the rate of
10% per annum on the unpaid balance.

         Said principal and interest shall be due and payable December 31, 1999.
         
         The  Company  may prepay this note  without  penalty.  In the event any
payment  due  hereunder  is not paid  when  due,  the  entire  balance  shall be
immediately due upon demand of any holder.  Upon default,  the company shall pay
all  reasonable  attorney fees and costs  necessary  for the  collection of this
note.
         Signed this 9th day of December, 1996.

                                                      For the Company:

                                                      /s/ A.Y. Cheung
                                                      A.Y. Cheung, President
                                                      Cheung Laboratories, Inc.