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  <xs:element id="aqst_RoyaltyObligationTerm" abstract="false" name="RoyaltyObligationTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
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  <xs:element id="aqst_NumberOfSharesReservedForIssuance" abstract="false" name="NumberOfSharesReservedForIssuance" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="aqst_AdjustmentsToAdditionalPaidInCapitalWarrantExercised" abstract="false" name="AdjustmentsToAdditionalPaidInCapitalWarrantExercised" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_AccountsReceivableAllowancesProvisionReversalRelatedToSales" abstract="false" name="AccountsReceivableAllowancesProvisionReversalRelatedToSales" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="aqst_RepurchaseOfferPercentageOfCashProceedsReceived" abstract="false" name="RepurchaseOfferPercentageOfCashProceedsReceived" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
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  <xs:element id="aqst_OperatingLeaseRemainingTerm" abstract="false" name="OperatingLeaseRemainingTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="aqst_DeferredTaxLiabilities481aAdjustment" abstract="false" name="DeferredTaxLiabilities481aAdjustment" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="aqst_ComputerNetworkEquipmentAndSoftwareMember" abstract="true" name="ComputerNetworkEquipmentAndSoftwareMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_InducementEquityCommonStockOptionsGrantedShares" abstract="false" name="InducementEquityCommonStockOptionsGrantedShares" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
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  <xs:element id="aqst_AssertioHoldingsIncMember" abstract="true" name="AssertioHoldingsIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
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  <xs:element id="aqst_EffectiveIncomeTaxRateReconciliationPermanentDifferencesPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationPermanentDifferencesPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="aqst_StockIssuedDuringPeriodValueWarrantsExercised" abstract="false" name="StockIssuedDuringPeriodValueWarrantsExercised" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="aqst_DebtInstrumentRedemptionPriceBasisSpreadOnVariableRate" abstract="false" name="DebtInstrumentRedemptionPriceBasisSpreadOnVariableRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
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  <xs:element id="aqst_IncomeTaxExaminationEmployeeRetentionTaxCreditRefund" abstract="false" name="IncomeTaxExaminationEmployeeRetentionTaxCreditRefund" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="aqst_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" abstract="true" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
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  <xs:element id="aqst_ProceedsFromIssuanceOfRoyaltyRightsAgreements" abstract="false" name="ProceedsFromIssuanceOfRoyaltyRightsAgreements" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="aqst_ScheduleOfSignificantUnobservableInputsUsedInTheInitialFairValueMeasurementOfTheRoyaltyRightAgreementTableTextBlock" abstract="false" name="ScheduleOfSignificantUnobservableInputsUsedInTheInitialFairValueMeasurementOfTheRoyaltyRightAgreementTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
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  <xs:element id="aqst_CommercialExploitationAgreementWithZevraMember" abstract="true" name="CommercialExploitationAgreementWithZevraMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_SaleOfStockAggregateOfferingPrice" abstract="false" name="SaleOfStockAggregateOfferingPrice" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipLimitationAfterAllTransactionsShares" abstract="false" name="SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipLimitationAfterAllTransactionsShares" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
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  <xs:element id="aqst_ElectiveRedemptionPercentageOfDebt" abstract="false" name="ElectiveRedemptionPercentageOfDebt" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="aqst_AtnahsPharmaUKLimitedAmendedAgreementMember" abstract="true" name="AtnahsPharmaUKLimitedAmendedAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_LicenseAndRoyaltyRevenueMember" abstract="true" name="LicenseAndRoyaltyRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_ManufacturingAndSupplyMember" abstract="true" name="ManufacturingAndSupplyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_DebtInstrumentAmountRedeemed" abstract="false" name="DebtInstrumentAmountRedeemed" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_MeasurementInputProbabilityOfSuccessMember" abstract="true" name="MeasurementInputProbabilityOfSuccessMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_AtTheMarketOfferingAmendmentOneMember" abstract="true" name="AtTheMarketOfferingAmendmentOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_IncomeTaxDisclosureLineItems" abstract="true" name="IncomeTaxDisclosureLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="aqst_RedemptionPercentageOfDebtUnderChangeOfControlProvisions" abstract="false" name="RedemptionPercentageOfDebtUnderChangeOfControlProvisions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="aqst_ConsultingFee" abstract="false" name="ConsultingFee" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_SaleOfStockRemainingAmountAvailableForOffering" abstract="false" name="SaleOfStockRemainingAmountAvailableForOffering" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_NetProceedsAfterPlacementAgentFeesExpensesAndOfferingExpensesPayable" abstract="false" name="NetProceedsAfterPlacementAgentFeesExpensesAndOfferingExpensesPayable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_NumberOfAnnualRoyaltyPaymentsReceivable" abstract="false" name="NumberOfAnnualRoyaltyPaymentsReceivable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="aqst_IndiviorAmendmentMember" abstract="true" name="IndiviorAmendmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_StockIssuedDuringPeriodValueCostsOfRegisteringCommonStockRelatedToWarrants" abstract="false" name="StockIssuedDuringPeriodValueCostsOfRegisteringCommonStockRelatedToWarrants" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_InterestExpenseSaleOfFutureRevenues" abstract="false" name="InterestExpenseSaleOfFutureRevenues" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_AtTheMarketOfferingMember" abstract="true" name="AtTheMarketOfferingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_CommonStockWarrantsMember" abstract="true" name="CommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_TradeAndOtherReceivablesNet" abstract="false" name="TradeAndOtherReceivablesNet" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_TransferOfFinancialAssetsAccountedForAsSalesAmountDerecognizedCurrent" abstract="false" name="TransferOfFinancialAssetsAccountedForAsSalesAmountDerecognizedCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_LiabilitiesSaleOfFutureRoyaltiesCurrent" abstract="false" name="LiabilitiesSaleOfFutureRoyaltiesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_DebtCovenantRedemptionScenarioDomain" abstract="true" name="DebtCovenantRedemptionScenarioDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_AgreementTerm" abstract="false" name="AgreementTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="aqst_ProprietaryProductSalesMember" abstract="true" name="ProprietaryProductSalesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_ShareBasedCompensationArrangementByShareBasedPaymentMarketConditionPerformancePriceThresholdVestingPercentageLimit" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentMarketConditionPerformancePriceThresholdVestingPercentageLimit" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="aqst_NinthThroughEighteenthMonthMember" abstract="true" name="NinthThroughEighteenthMonthMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_ResearchAndDevelopmentAmortizationPeriod" abstract="false" name="ResearchAndDevelopmentAmortizationPeriod" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="aqst_PrivateEquityMember" abstract="true" name="PrivateEquityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_ProceedsFromSaleOfFutureRevenuesNet" abstract="false" name="ProceedsFromSaleOfFutureRevenuesNet" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipLimitationAfterAllTransactions" abstract="false" name="SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipLimitationAfterAllTransactions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="aqst_ProceedsFromExerciseOfWarrantsNet" abstract="false" name="ProceedsFromExerciseOfWarrantsNet" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_LicenseAgreementWithSunovionPharmaceuticalsIncMilestonesMember" abstract="true" name="LicenseAgreementWithSunovionPharmaceuticalsIncMilestonesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_MarketConditionRangeTwoMember" abstract="true" name="MarketConditionRangeTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_ProceedsFromIssuancePrivateOffering" abstract="false" name="ProceedsFromIssuancePrivateOffering" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_AssetRetirementObligationsDepreciationExpense" abstract="false" name="AssetRetirementObligationsDepreciationExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_DebtInstrumentNumberOfNoticesOfRedemption" abstract="false" name="DebtInstrumentNumberOfNoticesOfRedemption" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="aqst_ShareBasedCompensationArrangementByShareBasedPaymentMarketConditionPerformancePriceThresholdVestingPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentMarketConditionPerformancePriceThresholdVestingPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="aqst_IssuanceDomain" abstract="true" name="IssuanceDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_InducementEquityCommonStockOptionsOutstandingShares" abstract="false" name="InducementEquityCommonStockOptionsOutstandingShares" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="aqst_AccountsReceivableAllowancesReclassifications" abstract="false" name="AccountsReceivableAllowancesReclassifications" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_ABLFacilityMember" abstract="true" name="ABLFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_EffectiveIncomeTaxRateReconciliationTaxCreditReturnToProvisionPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxCreditReturnToProvisionPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="aqst_MonetizationAgreementMember" abstract="true" name="MonetizationAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_TwelvePointFiveSeniorSecuredNotesDueJune302025Member" abstract="true" name="TwelvePointFiveSeniorSecuredNotesDueJune302025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="aqst_ExistingWarrantsMember" abstract="true" name="ExistingWarrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="aqst_DebtCovenantRedemptionScenarioAxis" abstract="true" name="DebtCovenantRedemptionScenarioAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="aqst_NetProceedsFromIssuanceOfInitialNotesWarrantsAndFirstOfferRights" abstract="false" name="NetProceedsFromIssuanceOfInitialNotesWarrantsAndFirstOfferRights" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_DurationOfPaymentAxis" abstract="true" name="DurationOfPaymentAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="aqst_DaysOfBasePay" abstract="false" name="DaysOfBasePay" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="aqst_AccountsReceivableAllowancesProvisionRelatedToSales" abstract="false" name="AccountsReceivableAllowancesProvisionRelatedToSales" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="aqst_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedOrExpectedToVestAggregateIntrinsicValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedOrExpectedToVestAggregateIntrinsicValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
