REVOLVING NOTE

$20,000,000                                                   Chicago, Illinois
                                                              June 18, 1997

         FOR VALUE RECEIVED,  on or before June 18, 2000 (or, if such day is not
a Business  Day, on the next  following  Business  Day),  the  undersigned,  K-V
PHARMACEUTICAL COMPANY, a Delaware corporation;  PARTICLE DYNAMICS,  INC., a New
York corporation;  and ETHEX CORPORATION,  a Missouri  corporation,  jointly and
severally (herein,  collectively and together with their successors and assigns,
called  "Borrowers"),  promise to pay to the order of LASALLE  NATIONAL  BANK, a
national banking association (herein,  together with its successors and assigns,
called the  "Bank"),  the  maximum  principal  sum of TWENTY  MILLION and 00/100
DOLLARS  ($20,000,000) or, if less, the aggregate unpaid principal amount of all
Revolving  Loans made by Bank to the  undersigned  pursuant to that certain Loan
Agreement of even date herewith between Borrowers and Bank (herein,  as the same
may be amended,  modified or  supplemented  from time to time,  called the "Loan
Agreement") as shown in Bank's records.

         The Borrower  further  promises to pay to the order of Bank interest on
the aggregate  unpaid principal amount hereof from time to time outstanding from
the date  hereof  until paid in full at such rates and at such times as shall be
determined in accordance  with the  provisions  of the Loan  Agreement.  Accrued
interest shall be payable on the dates specified in the Loan Agreement.

         Payments of both  principal  and  interest are to be made in the lawful
money of the United States of America in immediately  available  funds at Bank's
principal  office at 135 South LaSalle  Street,  Chicago,  Illinois 60603; or at
such other place as may be designated by Bank to the Borrower in writing.

         This Note is the Revolving Note referred to in, evidences  indebtedness
incurred  under,  and is  subject  to the  terms  and  provisions  of,  the Loan
Agreement.  The Loan  Agreement,  to which  reference is hereby made, sets forth
said terms and provisions,  including those under which this Note may or must be
paid prior to its due date or may have its due date accelerated.  Terms used but
not otherwise defined herein are used herein as defined in the Loan Agreement.

         In  addition  to,  and not in  limitation  of,  the  foregoing  and the
provisions of the Loan Agreement  hereinabove  referred to, the Borrower further
agrees,  subject only to any  limitation  imposed by applicable  law, to pay all
expenses, including attorneys' fees and expenses, incurred by the holder of this
Note in seeking to collect any amounts payable hereunder which are not paid when
due, whether by acceleration or otherwise.

         All  parties  hereto,  whether  as  makers,   endorsers  or  otherwise,
severally  waive  presentment,   demand,  protest  and  notice  of  dishonor  in
connection with this Note.

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         The  liability  of each  Borrower  under this Note in general  shall be
joint and several, and each reference herein to the Borrowers shall be deemed to
refer to each such  Borrower.  In  furtherance  and not in  limitation of Bank's
rights  and  remedies  hereunder  or at law,  Bank may  proceed  under this Note
against any one or more of the Borrowers in its absolute and sole discretion for
any of  Borrowers'  Liabilities  or any other  liability  or  obligation  of the
Borrowers arising hereunder.

         This  Note is  binding  upon the  undersigned  and its  successors  and
assigns,  and shall inure to the benefit of Bank and its successors and assigns.
This  Note is made  under  and  governed  by the laws of the  State of  Illinois
without regard to conflict of laws principles.


ATTEST:                                         K-V PHARMACEUTICAL COMPANY, a
                                                Delaware Corporation
By: /s/ John P. Walsh
    Assistant Secretary

Borrower's Address:                             By: /s/ Gerald R. Mitchell
                                                Title: Vice-President, Finance
2503 South Hanley
St. Louis, Missouri 63144-2555

ATTEST:                                         PARTICLE DYNAMICS, INC.,
                                                a New York corporation
By: /s/ John P. Walsh
    Secretary

Borrower's Address:                             By: /s/ Gerald R. Mitchell
                                                Title: Vice-President
2503 South Hanley
St. Louis, Missouri 63144-2555


ATTEST:                                         ETHEX CORPORATION, a
                                                Missouri corporation
By: /s/ John P. Walsh
    Secretary

Borrower's Address:                             By: /s/ Gerald R. Mitchell
                                                Title: Vice-President
2503 South Hanley
St. Louis, Missouri 63144-2555

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