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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001209191-10-031110.txt : 20100528
<SEC-HEADER>0001209191-10-031110.hdr.sgml : 20100528
<ACCEPTANCE-DATETIME>20100528153823
ACCESSION NUMBER:		0001209191-10-031110
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100526
FILED AS OF DATE:		20100528
DATE AS OF CHANGE:		20100528

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SLOAN GAIL A
		CENTRAL INDEX KEY:			0001237523

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24274
		FILM NUMBER:		10866641

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LA JOLLA PHARMACEUTICAL CO
		CENTRAL INDEX KEY:			0000920465
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				330361285
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4365 EXECUTIVE DRIVE, SUITE 300
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8584526600

	MAIL ADDRESS:	
		STREET 1:		4365 EXECUTIVE DRIVE, SUITE 300
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000920465</issuerCik>
        <issuerName>LA JOLLA PHARMACEUTICAL CO</issuerName>
        <issuerTradingSymbol>LJPC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237523</rptOwnerCik>
            <rptOwnerName>SLOAN GAIL A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4365 EXECUTIVE DRIVE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>94038</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.03</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>94038</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series C-1 Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.015</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>22</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1000.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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            </transactionAmounts>
            <exerciseDate>
                <value>2010-12-03</value>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1466674</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Series C-2 Convertible Pfd Stock Warrants (right to buy)</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1000.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>44</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-05-26</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-05-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Series C-2 Convertible Preferred Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>44</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>44</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Series D-1 Convertible Pfd Stock Warrants (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1000.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>22</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-05-26</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-05-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Series D-1 Convertible Preferred Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>22</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Series C-1 Convertible Preferred Stock (the &quot;Series C-1 Stock&quot;) is initially convertible into shares of common stock of La Jolla Pharmaceutical Company at a price per share of $0.015, but such conversion price will be adjusted for certain events, such as stock splits, stock dividends, reclassifications and recapitalizations, and is subject to full-ratchet anti-dilution protection such that any subsequent issuance of common stock below $0.015 automatically adjusts the conversion price of the Series C-1 Stock to such lower price.</footnote>
        <footnote id="F2">The Series C-1 Stock does not have a set expiration date, although the holders of such stock may require the Company to redeem the Series C-1 Stock upon certain events.</footnote>
        <footnote id="F3">Upon exercise of these Series C-2 Convertible Preferred Stock Warrants, Ms. Sloan will receive up to 44 shares of Series C-2 Convertible Preferred Stock and warrants to purchase up to 44 shares of Series D-2 Convertible Preferred Stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Gail A. Sloan</signatureName>
        <signatureDate>2010-05-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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