Administration, OralDrug Administration ScheduleInjections, IntravenousUnited States Food and Drug AdministrationDose-Response Relationship, DrugTime FactorsDrug Administration RoutesRats, Sprague-DawleyRats, WistarAdministration, IntranasalInjections, IntraperitonealDisease Models, AnimalWorld Health OrganizationMice, Inbred C57BLInjections, SubcutaneousLiverAdministration, RectalBiological AvailabilityInjections, IntramuscularInfusions, IntravenousAdministration, TopicalHalf-LifeOrganizationsAdministration, IntravenousDrug InteractionsArea Under CurveInjections, IntraventricularTissue DistributionMice, Inbred BALB CDogsRats, Inbred StrainsBrainMolecular Sequence DataTreatment OutcomeAdministration, CutaneousDouble-Blind MethodRNA, MessengerKidneyUnited StatesRecombinant ProteinsCross-Over StudiesBlood PressureBehavior, AnimalAdministration, SublingualBody WeightRandom AllocationAdministration, InhalationBase SequenceInfusions, ParenteralAnalysis of VarianceRabbitsMorphineDrug TolerancePregnancyInjectionsPlant ExtractsHealth Maintenance OrganizationsOrgan SizeChromatography, High Pressure LiquidMice, KnockoutAmino Acid SequenceCells, CulturedMice, Inbred ICRInjections, SpinalLungMetabolic Clearance RateMotor ActivityRats, Inbred F344Accountable Care OrganizationsDrug CombinationsAnalgesics, OpioidAntineoplastic AgentsEthanolImmunohistochemistryMice, Inbred StrainsSelf AdministrationEstradiolHeart RateModels, BiologicalEnzyme InhibitorsAntibodies, MonoclonalOrganizations, NonprofitHemodynamicsDrug Therapy, CombinationDrug Evaluation, PreclinicalNeuronsAnalgesicsSpleenBlood GlucoseDrug ApprovalAnimals, NewbornGene Expression RegulationSignal TransductionKineticsInjections, Intra-ArterialAdministration, BuccalPiperidinesAnti-Inflammatory Agents, Non-SteroidalProdrugsGene Expression