<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-11-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001427925</issuerCik>
        <issuerName>ACELRX PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>ACRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001700225</rptOwnerCik>
            <rptOwnerName>Angotti Vincent J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ACELRX PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>351 GALVESTON DRIVE</rptOwnerStreet2>
            <rptOwnerCity>REDWOOD CITY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94063</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>267565</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.225</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-11-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>96250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2019-11-02</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-11-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>96250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>192500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Balance includes non-reportable acquisition of 4,681 shares of Common Stock through the Company's Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">On April 7, 2018, the reporting person was granted a performance-based option to purchase 192,500 shares of common stock, subject to the Company's achievement of commercial approval by the U.S. Food and Drug Administration (&quot;FDA&quot;) of its new drug application for &quot;DSUVIA&quot; on or before February 15, 2019. Once the performance criteria is achieved, the option vests in two equal installments with 50% of the option vesting upon the Company's achievement of the performance criteria and the remaining 50% of the option vesting on the one-year anniversary of the date of such achievement, in all cases subject to continuous service to the Company. The performance criteria for commercial approval by the FDA for DSUVIA was met on November 2, 2018, resulting in vesting of the option as to 96,250 shares on that date. On November 2, 2019, the remaining balance of the option vested.</footnote>
    </footnotes>

    <remarks>Exhibit List - Exhibit 24.1 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Martha Adler, Attorney-In-Fact</signatureName>
        <signatureDate>2019-11-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
