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  <element name="ExercisePriceForOptionToFairValueMinimum" id="hznp_ExercisePriceForOptionToFairValueMinimum" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FairValueAssumptionsInterestRatePercentage" id="hznp_FairValueAssumptionsInterestRatePercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FdaProductAndManufacturingFeesMember" id="hznp_FdaProductAndManufacturingFeesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FiniteLivedIntangibleAssetsAmortizationExpenseYearFiveAndThereafter" id="hznp_FiniteLivedIntangibleAssetsAmortizationExpenseYearFiveAndThereafter" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FourthAnniversaryMember" id="hznp_FourthAnniversaryMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GainLossRecognizedOnRevaluation" id="hznp_GainLossRecognizedOnRevaluation" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GovernmentRebatesAndChargebacks" id="hznp_GovernmentRebatesAndChargebacks" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="HorizonPharmaPlcMember" id="hznp_HorizonPharmaPlcMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncreaseDecreaseInAccountsTradeDiscountsAndRebates" id="hznp_IncreaseDecreaseInAccountsTradeDiscountsAndRebates" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="JagotecAgMember" id="hznp_JagotecAgMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LegalProceedingsInfringementSuitInParagraphFourNoticePeriod" id="hznp_LegalProceedingsInfringementSuitInParagraphFourNoticePeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LegalProceedingsInfringementSuitPreventionPeriod" id="hznp_LegalProceedingsInfringementSuitPreventionPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LegalProceedingsLineItems" id="hznp_LegalProceedingsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LegalProceedingsTable" id="hznp_LegalProceedingsTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="LicenseAgreementGenericEntryDate" id="hznp_LicenseAgreementGenericEntryDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LineOfCreditFacilityCommitmentFeePercentageThereafter" id="hznp_LineOfCreditFacilityCommitmentFeePercentageThereafter" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LineOfCreditFacilityCommittedBorrowingCapacity" id="hznp_LineOfCreditFacilityCommittedBorrowingCapacity" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LodotraMember" id="hznp_LodotraMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LodotraOrRayosProductMember" id="hznp_LodotraOrRayosProductMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MannheimOfficeMember" id="hznp_MannheimOfficeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ManufacturingAndSupplyAgreementInitiationDate" id="hznp_ManufacturingAndSupplyAgreementInitiationDate" type="xbrli:gYearMonthItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MinorityInterestOwnershipSharesByParent" id="hznp_MinorityInterestOwnershipSharesByParent" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NewHorizonMember" id="hznp_NewHorizonMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NonRefundableInvestmentBankerFeesExpensed" id="hznp_NonRefundableInvestmentBankerFeesExpensed" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfAmendments" id="hznp_NumberOfAmendments" type="xbrli:integerItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfMajorCustomersAccountedForRevenue" id="hznp_NumberOfMajorCustomersAccountedForRevenue" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfMajorCustomersAccountedForTradeAccountsReceivable" id="hznp_NumberOfMajorCustomersAccountedForTradeAccountsReceivable" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfSalesRepresentative" id="hznp_NumberOfSalesRepresentative" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfWarrantsExercised" id="hznp_NumberOfWarrantsExercised" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OutOfPeriodAdjustmentCostOfSales" id="hznp_OutOfPeriodAdjustmentCostOfSales" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PercentageOfAdditionalSharesFromCommonStockAvailableForStockBasedCompensation" id="hznp_PercentageOfAdditionalSharesFromCommonStockAvailableForStockBasedCompensation" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PercentageOfForfeitureRate" id="hznp_PercentageOfForfeitureRate" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PercentageOfRoyaltyOnNetSales" id="hznp_PercentageOfRoyaltyOnNetSales" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PreclinicalStudyAndClinicalTrialAccrualsPolicyTextBlock" id="hznp_PreclinicalStudyAndClinicalTrialAccrualsPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PrepaidExpensesAndOtherCurrentAssetsLineItems" id="hznp_PrepaidExpensesAndOtherCurrentAssetsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PrepaidExpensesAndOtherCurrentAssetsTable" id="hznp_PrepaidExpensesAndOtherCurrentAssetsTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="PrepaymentPremiumAsPercentageOfLoanPrepaidInSubsequentYear" id="hznp_PrepaymentPremiumAsPercentageOfLoanPrepaidInSubsequentYear" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PreTaxAmountOfNonVestedStockOptionsAndRestrictedStockAwardsAndUnitsNotYetRecognized" id="hznp_PreTaxAmountOfNonVestedStockOptionsAndRestrictedStockAwardsAndUnitsNotYetRecognized" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ProceedsFromAtMarketIssuanceOfCommonStockNetOfIssuanceCosts" id="hznp_ProceedsFromAtMarketIssuanceOfCommonStockNetOfIssuanceCosts" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PropertyAndEquipmentExpectedUsefulLifeTableTextBlock" id="hznp_PropertyAndEquipmentExpectedUsefulLifeTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PurchaseOrderIssued" id="hznp_PurchaseOrderIssued" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RayosMember" id="hznp_RayosMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReinachOfficeMember" id="hznp_ReinachOfficeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RoyaltiesMember" id="hznp_RoyaltiesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RoyaltyPayments" id="hznp_RoyaltyPayments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SalesAndMarketingMember" id="hznp_SalesAndMarketingMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SanofiAventisMember" id="hznp_SanofiAventisMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfAccruedTradeDiscountsAndRebatesTableTextBlock" id="hznp_ScheduleOfAccruedTradeDiscountsAndRebatesTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SecondAmendedAgreementMember" id="hznp_SecondAmendedAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SeniorSecuredCreditFacilityMember" id="hznp_SeniorSecuredCreditFacilityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumEmployeeSubscriptionRate" id="hznp_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumEmployeeSubscriptionRate" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsToVestUnderServicePeriodUponAchievementOfPerformanceConditions" id="hznp_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsToVestUnderServicePeriodUponAchievementOfPerformanceConditions" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestingPeriodOneMinimum" id="hznp_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestingPeriodOneMinimum" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SoftwareLicensesMember" id="hznp_SoftwareLicensesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SummaryOfSignificantAccountingPoliciesLineItems" id="hznp_SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SummaryOfSignificantAccountingPoliciesTable" id="hznp_SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="TermPeriodOfCreditFacility" id="hznp_TermPeriodOfCreditFacility" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ThirdAmendedAgreementMember" id="hznp_ThirdAmendedAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ThirdAnniversaryMember" id="hznp_ThirdAnniversaryMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TickingFeeAccrualPeriod" id="hznp_TickingFeeAccrualPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TickingFeeAccrualPeriodRevised" id="hznp_TickingFeeAccrualPeriodRevised" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandAndFourteenMember" id="hznp_TwoThousandAndFourteenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandElevenEmployeeStockPurchasePlanMember" id="hznp_TwoThousandElevenEmployeeStockPurchasePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandElevenEquityIncentivePlanMember" id="hznp_TwoThousandElevenEquityIncentivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandFivePlanMember" id="hznp_TwoThousandFivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnvestedRestrictedStockUnitsMember" id="hznp_UnvestedRestrictedStockUnitsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UpFrontFeeAndMilestonePaymentArrangementMember" id="hznp_UpFrontFeeAndMilestonePaymentArrangementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VimovoIntellectualPropertyMember" id="hznp_VimovoIntellectualPropertyMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="WholesalerFeesMember" id="hznp_WholesalerFeesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
</schema>


