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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 TPJen0lfce8OW2dS0Saghgx+GgrZCfc6IIyApG++JOHJ15pEmFTgDRPl4hp5GZsa
 G062iIchJV8F19fZkJOjTQ==

<SEC-DOCUMENT>0001209191-03-022316.txt : 20030919
<SEC-HEADER>0001209191-03-022316.hdr.sgml : 20030919
<ACCEPTANCE-DATETIME>20030919180346
ACCESSION NUMBER:		0001209191-03-022316
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030918
FILED AS OF DATE:		20030919

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:		03903264

	BUSINESS ADDRESS:	
		STREET 1:		645 NANCY RIDGE DRIVE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8586466644

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:		6455 NANCY RIDGE DR
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8584526600

	MAIL ADDRESS:	
		STREET 1:		6455 NANCY RIDGE DR
		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>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-09-18</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>6455 NANCY RIDGE DRIVE</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>Sen Dir of Finance/Controller</officerTitle></reportingOwnerRelationship></repor
tingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-06-30</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1" /></transactionCoding><transactionTimeliness><value>E</value></transactionTimeliness><transactionAmounts><transactionShares><value>275</value></transactionShares><transactionPricePerShare><value>1.479</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11314</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable
><derivativeTransaction><securityTitle><value>Stock Options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>4.71</value></conversionOrExercisePrice><transactionDate><value>2003-09-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>7500</value></transactionShares><transactionPricePerShare><value>4.71</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F2" /></exerciseDate><expirationDate><value>2013-09-18</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>7500</value></underlyingSecurit
yShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>196700</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>Stock Options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>4.71</value></conversionOrExercisePrice><transactionDate><value>2003-09-18</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>22500</value></transactionShares><transactionPricePerShare><value>4.71</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedC
ode></transactionAmounts><exerciseDate><footnoteId id="F2" /></exerciseDate><expirationDate><value>2013-09-18</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>22500</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>219200</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Acquired pursuant to the Company???s Employee Stock Purchase Plan.</footnote><footnote id="F2">The stock options vest and become exercisable monthly over the next three years.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>/s/ Gail A. Sloan</signatureName><signatureDate>2003-09-19</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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