content: <PAGE>
   
   
                                   UNITED STATES                
                        SECURITIES AND EXCHANGE COMMISSION      
                              Washington, D.C. 20549            
                                                                
                                     FORM 144
  
                       NOTICE OF PROPOSED SALE OF SECURITIES
               PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
  
                                                              OMB APPROVAL     
                                                       ---------------------------
                                                       OMB Number: 3235-0101 
                                                       Expires: September 30, 1995
                                                       Estimate average burden
                                                       hours per response .... 2.0
                                                       ---------------------------
                                                       ---------------------------
                                                              SEC USE ONLY
                                                       ---------------------------
                                                       DOCUMENT SEQUENCE NO. 
  
                                                       ---------------------------
                                                       CUSIP NUMBER
  
                                                       ---------------------------
                                                       WORK LOCATION
  
                                                       ---------------------------
  
  ATTENTION: Transmit for filing 3 copies of this form concurrently with either
             placing an order with a broker to execute sale or executing a sale
             with a market maker.
  --------------------------------------------------------------------------------
  1(a) NAME OF ISSUER (Please type or print)
  
  CYTOGEN CORPORATION (CYTO)
  --------------------------------------------------------------------------------
  (b) IRS IDENT. NO.
  
  222322400
  --------------------------------------------------------------------------------
  (c) S.E.C. FILE NO.
  
  
  --------------------------------------------------------------------------------
  1(d) ADDRESS OF ISSUER       STREET        CITY        STATE         ZIP CODE
  
  600 COLLEGE ROAD EAST,                  PRINCETON,       NJ           08540
  --------------------------------------------------------------------------------
  (e) TELEPHONE NUMBER
  --------------------------
   AREA CODE    NUMBER   
     609       987-8200
    ------    --------------
  --------------------------------------------------------------------------------
  2(a) NAME OF PERSON FOR WHOSE ACCOUNT THE SECURITIES ARE TO BE SOLD
  
  JOHN D. RODWELL
  --------------------------------------------------------------------------------
  (b) SOCIAL SECURITY NO OR IRS IDENT. NO.
  
  
  --------------------------------------------------------------------------------
  (c) RELATIONSHIP TO ISSUER
  
  OFFICER
  --------------------------------------------------------------------------------
  (d) ADDRESS                 STREET        CITY        STATE         ZIP CODE
  
  1340 EAGLE ROAD                         NEW HOPE       PA            18938
  --------------------------------------------------------------------------------
  
  INSTRUCTION: The person filing this notice should contact the issuer to obtain 
               the I.R.S. Identification Number and the S.E.C. file Number.
  
  <TABLE> 
  <CAPTION> 
  ----------------------------------------------------------------------------------------------------------------------
  3(a)              (b)                                                       SEC USE ONLY         (c)                  
      Title of the     Name and Address of Each Broker Through Whom the       -------------           Number of Shares  
        Class of        Securities are to be Offered or Each Market           Broker-Dealer            or Other Units
       Securities        Maker who is Acquiring the Securities                 File Number              To Be Sold
       To be Sold                                                                                     (See instr. 3(c))
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  <S>               <C>                                                       <C>                  <C> 
  COMMON STOCK      DEAN WITTER REYNOLDS, INC.                                                         19,100
                    200 E. NEW ENGLAND AVE, 4TH FL.
                    WINTER PARK, FL 32789
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  
  
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  
  
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  <CAPTION> 
  ----------------------------------------------------------------------------------------------------------------------
  (d)                       (e)                           (f)                         (g)
      Aggregate                Number of Shares               Approximate                Name of Each
       Market                   or Other Units               Date of Sale                 Securities
       Value                     Outstanding                (See instr. 3(f))              Exchange
     (See instr. 3(d))         (See instr. 3(e))             (MO. DAY YR.)               (See instr. 3(g))
  --------------------      --------------------          -------------------          ------------------- 
  <S>                       <C>                           <C>                          <C> 
    $105,050                   51,081,533                     4/4/97                       NASDAQ
  --------------------      --------------------          -------------------          ------------------- 
  
  
  --------------------      --------------------          -------------------          ------------------- 
  
  
  --------------------      --------------------          -------------------          ------------------- 
  </TABLE> 
  INSTRUCTIONS
  
  1. (a) Name of Issuer
     (b) Issuer's I.R.S. Identification Number
     (c) Issuer's S.E.C. file number, if any
     (d) Issuer's address, including zip code
     (e) Issuer's telephone number, including area code
  
  2. (a) Name of person for whose account the securities are to be sold
     (b) Such person's Social Security or I.R.S. identification number
     (c) Such person's relationship to the issuer (e.g., officer, director, 10%
         stockholder, or member of immediate family of any of the foregoing)
     (d) Such person's address, including zip code
  
  3. (a) Title of the class of securities to be sold
     (b) Name and address of each broker through whom the securities are intended
         to be sold
     (c) Number of shares or other units to be sold (if debt securities, give the 
         aggregate face amount)
     (d) Aggregate market value of the securities to be sold as of a specified 
         date within 10 days prior to the filing of this notice.
     (e) Number of shares or other units of the class outstanding, or if debt 
         securities the face amount thereof outstanding, as shown by the most 
         recent report or statement published by the issuer
     (f) Approximate date on which the securities are to be sold
     (g) Name of each securities exchange, if any, on which the securities are 
         intended to be sold
  
  
                                                                   SEC 1147 (9-93)
  
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  
  <TABLE> 
  <CAPTION>  
                                                   TABLE I -- SECURITIES TO BE SOLD
  
                    Furnish the following information with respect to the acquisition of the securities to be sold
               and with respect to the payment of all or any part of the purchase price or other consideration therefor:
  
  
                                                                Name of Person       
                                                                 Whom Acquired        
  Title of    Date you                                        (If gift, also give         Amount of         Date of        
  the Class   Acquired   Nature of Acquisition Transaction    date donor acquired)   Securities Acquired   Payment  Nature of Payment
  ---------   --------   ---------------------------------   ---------------------   -------------------   -------  ----------------- 
  <S>         <C>        <C>                                  <C>                     <C>                   <C>      <C> 
  COMMON      11/30/88   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION          3,100                                   
   STOCK                                                                                                                   
  COMMON      01/26/89   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION          4,000
   STOCK                                                                                                                   
  COMMON      12/08/94   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION         12,000
    STOCK                                                                                                                   
  ---------   --------   ---------------------------------   ---------------------   -------------------   -------  ----------------- 
  </TABLE> 
  INSTRUCTIONS: 1. If the securities were purchased and full payment therefor was
                   not made in cash at the time of purchase, explain in the table
                   or in a note thereto the nature of the consideration given.
                   If the consideration consisted of any note or other obligation,
                   or if payment was made in installments describe the arrangement
                   and state when the note or other obligation was discharged in
                   full or the last installment paid.
  
                2. If within two years after the acquisition of the securities the
                   person for whose account they are to be sold had any short
                   positions, put or other option to dispose of securities
                   referred to in paragraph (d)(3) of Rule 144, furnish full
                   information with respect thereto.
                 
  <TABLE> 
  <CAPTION> 
  
                                         TABLE II -- SECURITIES SOLD DURING THE PAST 3 MONTHS
  
                           Furnish the following information as to all securities of the issuer sold during 
                           the past 3 months by the person for whose account the securities are to be sold.
  
                                                                                              Amount of
       Name and Address of Seller           Title of Securities Sold       Date of Sale     Securities Sold    Gross Proceeds
  -------------------------------------   ----------------------------   ----------------  -----------------  ----------------
  <S>                                     <C>                            <C>               <C>                <C>  
  
  JOHN D. RODWELL                                   NONE
  
  
  
  -------------------------------------   ----------------------------   ----------------  -----------------  ----------------
  </TABLE> 
  REMARKS:
  
  INSTRUCTIONS:
  
  See the definition of "person" in paragraph (a) of Rule 144. Information is to
  be given not only as to the person for whose account the securities are to be
  sold but also as to all other persons included in that definition. In addition,
  information shall be given as to sales by all persons whose sales are required
  by paragraph (e) of Rule 144 to be aggregated with sales for the account of the
  person filing this notice.
  
                            APRIL 3, 1997
                     ----------------------------------------
                                  DATE OF NOTICE
  
  
  ATTENTION:
  
  The person for whose account the securities to which this notice relates are to 
  be sold hereby represents by signing this notice that he does not know any 
  material adverse information in regard to the current and prospective operations
  of the Issuer of the securities to be sold which has not been publicly 
  disclosed.
  
                       \S\ JOHN D. RODWELL
                     ----------------------------------------
                           SIGNATURE
                           JOHN D. RODWELL
  
  
  
     The notice shall be signed by the person for whose account the securities
     are to be sold. At least one copy of the notice shall be manually signed.
     Any copies not manually signed shall bear typed or printed signatures.
  
  --------------------------------------------------------------------------------
  ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSION OF FACTS CONSTITUTE 
             FEDERAL CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)
  --------------------------------------------------------------------------------
  
                                                                   SEC 1147 (9-93)
metadata_documents: [{"type": "144", "sequence": "1", "description": "FORM 144", "secsgml_size_bytes": 13263}]
text: UNITED STATES                
                        SECURITIES AND EXCHANGE COMMISSION      
                              Washington, D.C. 20549            
                                                                
                                     FORM 144
  
                       NOTICE OF PROPOSED SALE OF SECURITIES
               PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
  
                                                              OMB APPROVAL     
                                                       ---------------------------
                                                       OMB Number: 3235-0101 
                                                       Expires: September 30, 1995
                                                       Estimate average burden
                                                       hours per response .... 2.0
                                                       ---------------------------
                                                       ---------------------------
                                                              SEC USE ONLY
                                                       ---------------------------
                                                       DOCUMENT SEQUENCE NO. 
  
                                                       ---------------------------
                                                       CUSIP NUMBER
  
                                                       ---------------------------
                                                       WORK LOCATION
  
                                                       ---------------------------
  
  ATTENTION: Transmit for filing 3 copies of this form concurrently with either
             placing an order with a broker to execute sale or executing a sale
             with a market maker.
  --------------------------------------------------------------------------------
  1(a) NAME OF ISSUER (Please type or print)
  
  CYTOGEN CORPORATION (CYTO)
  --------------------------------------------------------------------------------
  (b) IRS IDENT. NO.
  
  222322400
  --------------------------------------------------------------------------------
  (c) S.E.C. FILE NO.
  
  --------------------------------------------------------------------------------
  1(d) ADDRESS OF ISSUER       STREET        CITY        STATE         ZIP CODE
  
  600 COLLEGE ROAD EAST,                  PRINCETON,       NJ           08540
  --------------------------------------------------------------------------------
  (e) TELEPHONE NUMBER
  --------------------------
   AREA CODE    NUMBER   
     609       987-8200
    ------    --------------
  --------------------------------------------------------------------------------
  2(a) NAME OF PERSON FOR WHOSE ACCOUNT THE SECURITIES ARE TO BE SOLD
  
  JOHN D. RODWELL
  --------------------------------------------------------------------------------
  (b) SOCIAL SECURITY NO OR IRS IDENT. NO.
  
  --------------------------------------------------------------------------------
  (c) RELATIONSHIP TO ISSUER
  
  OFFICER
  --------------------------------------------------------------------------------
  (d) ADDRESS                 STREET        CITY        STATE         ZIP CODE
  
  1340 EAGLE ROAD                         NEW HOPE       PA            18938
  --------------------------------------------------------------------------------
  
  INSTRUCTION: The person filing this notice should contact the issuer to obtain 
               the I.R.S. Identification Number and the S.E.C. file Number.
  ----------------------------------------------------------------------------------------------------------------------
  3(a)              (b)                                                       SEC USE ONLY         (c)                  
      Title of the     Name and Address of Each Broker Through Whom the       -------------           Number of Shares  
        Class of        Securities are to be Offered or Each Market           Broker-Dealer            or Other Units
       Securities        Maker who is Acquiring the Securities                 File Number              To Be Sold
       To be Sold                                                                                     (See instr. 3(c))
  ----------------  ----------------------------------------------------      -------------        ---------------------
  COMMON STOCK      DEAN WITTER REYNOLDS, INC.                                                         19,100
                    200 E. NEW ENGLAND AVE, 4TH FL.
                    WINTER PARK, FL 32789
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  
  ----------------  ----------------------------------------------------      -------------        --------------------- 
  
  ----------------  ----------------------------------------------------      -------------        ---------------------
  ----------------------------------------------------------------------------------------------------------------------
  (d)                       (e)                           (f)                         (g)
      Aggregate                Number of Shares               Approximate                Name of Each
       Market                   or Other Units               Date of Sale                 Securities
       Value                     Outstanding                (See instr. 3(f))              Exchange
     (See instr. 3(d))         (See instr. 3(e))             (MO. DAY YR.)               (See instr. 3(g))
  --------------------      --------------------          -------------------          -------------------
  $105,050                   51,081,533                     4/4/97                       NASDAQ
  --------------------      --------------------          -------------------          ------------------- 
  
  --------------------      --------------------          -------------------          ------------------- 
  
  --------------------      --------------------          -------------------          -------------------
  INSTRUCTIONS
  
  1. (a) Name of Issuer
     (b) Issuer's I.R.S. Identification Number
     (c) Issuer's S.E.C. file number, if any
     (d) Issuer's address, including zip code
     (e) Issuer's telephone number, including area code
  
  2. (a) Name of person for whose account the securities are to be sold
     (b) Such person's Social Security or I.R.S. identification number
     (c) Such person's relationship to the issuer (e.g., officer, director, 10%
         stockholder, or member of immediate family of any of the foregoing)
     (d) Such person's address, including zip code
  
  3. (a) Title of the class of securities to be sold
     (b) Name and address of each broker through whom the securities are intended
         to be sold
     (c) Number of shares or other units to be sold (if debt securities, give the 
         aggregate face amount)
     (d) Aggregate market value of the securities to be sold as of a specified 
         date within 10 days prior to the filing of this notice.
     (e) Number of shares or other units of the class outstanding, or if debt 
         securities the face amount thereof outstanding, as shown by the most 
         recent report or statement published by the issuer
     (f) Approximate date on which the securities are to be sold
     (g) Name of each securities exchange, if any, on which the securities are 
         intended to be sold
  
                                                                   SEC 1147 (9-93)
  
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  TABLE I -- SECURITIES TO BE SOLD
  
                    Furnish the following information with respect to the acquisition of the securities to be sold
               and with respect to the payment of all or any part of the purchase price or other consideration therefor:
  
                                                                Name of Person       
                                                                 Whom Acquired        
  Title of    Date you                                        (If gift, also give         Amount of         Date of        
  the Class   Acquired   Nature of Acquisition Transaction    date donor acquired)   Securities Acquired   Payment  Nature of Payment
  ---------   --------   ---------------------------------   ---------------------   -------------------   -------  -----------------
  COMMON      11/30/88   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION          3,100                                   
   STOCK                                                                                                                   
  COMMON      01/26/89   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION          4,000
   STOCK                                                                                                                   
  COMMON      12/08/94   STOCK OPTION (RIGHT TO BUY)          CYTOGEN CORPORATION         12,000
    STOCK                                                                                                                   
  ---------   --------   ---------------------------------   ---------------------   -------------------   -------  -----------------
  INSTRUCTIONS: 1. If the securities were purchased and full payment therefor was
                   not made in cash at the time of purchase, explain in the table
                   or in a note thereto the nature of the consideration given.
                   If the consideration consisted of any note or other obligation,
                   or if payment was made in installments describe the arrangement
                   and state when the note or other obligation was discharged in
                   full or the last installment paid.
  
                2. If within two years after the acquisition of the securities the
                   person for whose account they are to be sold had any short
                   positions, put or other option to dispose of securities
                   referred to in paragraph (d)(3) of Rule 144, furnish full
                   information with respect thereto.
  TABLE II -- SECURITIES SOLD DURING THE PAST 3 MONTHS
  
                           Furnish the following information as to all securities of the issuer sold during 
                           the past 3 months by the person for whose account the securities are to be sold.
  
                                                                                              Amount of
       Name and Address of Seller           Title of Securities Sold       Date of Sale     Securities Sold    Gross Proceeds
  -------------------------------------   ----------------------------   ----------------  -----------------  ----------------
  JOHN D. RODWELL                                   NONE
  
  -------------------------------------   ----------------------------   ----------------  -----------------  ----------------
  REMARKS:
  
  INSTRUCTIONS:
  
  See the definition of "person" in paragraph (a) of Rule 144. Information is to
  be given not only as to the person for whose account the securities are to be
  sold but also as to all other persons included in that definition. In addition,
  information shall be given as to sales by all persons whose sales are required
  by paragraph (e) of Rule 144 to be aggregated with sales for the account of the
  person filing this notice.
  
                            APRIL 3, 1997
                     ----------------------------------------
                                  DATE OF NOTICE
  
  ATTENTION:
  
  The person for whose account the securities to which this notice relates are to 
  be sold hereby represents by signing this notice that he does not know any 
  material adverse information in regard to the current and prospective operations
  of the Issuer of the securities to be sold which has not been publicly 
  disclosed.
  
                       \S\ JOHN D. RODWELL
                     ----------------------------------------
                           SIGNATURE
                           JOHN D. RODWELL
  
     The notice shall be signed by the person for whose account the securities
     are to be sold. At least one copy of the notice shall be manually signed.
     Any copies not manually signed shall bear typed or printed signatures.
  
  --------------------------------------------------------------------------------
  ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSION OF FACTS CONSTITUTE 
             FEDERAL CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)
  --------------------------------------------------------------------------------
  
                                                                   SEC 1147 (9-93)