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<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 17-March-2023 [04:51:20] {PM}-->
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_ClosingStockPrices" xlink:label="loc_lnth_ClosingStockPrices" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_lnth_ClosingStockPrices" xml:lang="en-US">Closing Stock Prices</label>
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_SctValueOfStockAndOptionAwardsMember" xlink:label="loc_lnth_SctValueOfStockAndOptionAwardsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_lnth_SctValueOfStockAndOptionAwardsMember" xml:lang="en-US">SCT Value of Stock and Option Awards [Member]</label>
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_FairValueAtYearendOfAwardsGrantedDuringTheCoveredFiscalYearThatAreOutstandingAndUnvestedAtYearendMember" xlink:label="loc_lnth_FairValueAtYearendOfAwardsGrantedDuringTheCoveredFiscalYearThatAreOutstandingAndUnvestedAtYearendMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_lnth_FairValueAtYearendOfAwardsGrantedDuringTheCoveredFiscalYearThatAreOutstandingAndUnvestedAtYearendMember" xml:lang="en-US">Fair value at yearend of awards granted during the covered fiscal year that are outstanding and unvested at yearend [Member]</label>
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_YearOverYearChangeInFairValueOfAwardsGrantedInAnyPriorFiscalYearThatAreOutstandingAndUnvestedAtYearEndMember" xlink:label="loc_lnth_YearOverYearChangeInFairValueOfAwardsGrantedInAnyPriorFiscalYearThatAreOutstandingAndUnvestedAtYearEndMember" />
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_ChangeAsOfTheVestingDateFromTheEndOfThePriorFiscalYearInFairValueOfAwardsGrantedInAnyPriorFiscalYearForWhichVestingConditionsWereSatisfiedDuringSuchYearMember" xlink:label="loc_lnth_ChangeAsOfTheVestingDateFromTheEndOfThePriorFiscalYearInFairValueOfAwardsGrantedInAnyPriorFiscalYearForWhichVestingConditionsWereSatisfiedDuringSuchYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_lnth_ChangeAsOfTheVestingDateFromTheEndOfThePriorFiscalYearInFairValueOfAwardsGrantedInAnyPriorFiscalYearForWhichVestingConditionsWereSatisfiedDuringSuchYearMember" xml:lang="en-US">Change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during such year [Member]</label>
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<loc xlink:type="locator" xlink:href="lnth-20221231.xsd#lnth_FairValueAtEndOfPriorYearOfAwardsGrantedInAnyPriorFiscalYearThatFailToMeetTheApplicableVestingConditionsDuringSuchYearMember" xlink:label="loc_lnth_FairValueAtEndOfPriorYearOfAwardsGrantedInAnyPriorFiscalYearThatFailToMeetTheApplicableVestingConditionsDuringSuchYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_lnth_FairValueAtEndOfPriorYearOfAwardsGrantedInAnyPriorFiscalYearThatFailToMeetTheApplicableVestingConditionsDuringSuchYearMember" xml:lang="en-US">Fair value at end of prior year of awards granted in any prior fiscal year that fail to meet the applicable vesting conditions during such year [Member]</label>
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