Administration, OralDrug Administration RoutesInjections, IntravenousDrug Administration ScheduleUnited States Food and Drug AdministrationAdministration, IntranasalTime FactorsDose-Response Relationship, DrugRats, Sprague-DawleyInjections, IntraperitonealInjections, SubcutaneousRats, WistarDisease Models, AnimalInjections, IntramuscularAdministration, RectalBiological AvailabilityMice, Inbred C57BLHalf-LifeLiverAdministration, TopicalInfusions, IntravenousMice, Inbred BALB CAdministration, CutaneousAdministration, IntravenousArea Under CurveInjections, IntraventricularDrug InteractionsTissue DistributionAdministration, SublingualDogsRats, Inbred StrainsAdministration, InhalationTreatment OutcomeBrainDouble-Blind MethodCross-Over StudiesInjectionsKidneyBlood PressureRandom AllocationBody WeightRecombinant ProteinsChromatography, High Pressure LiquidBehavior, AnimalInfusions, ParenteralMorphineLungInjections, SpinalMetabolic Clearance RateDrug ToleranceAnalysis of VarianceMice, Inbred ICRPlant ExtractsInjections, IntradermalRNA, MessengerOrgan SizeSpleenRats, Inbred F344PregnancyAnalgesics, OpioidInjections, Intra-ArterialMice, Inbred StrainsRabbitsEthanolAntineoplastic AgentsDrug Evaluation, PreclinicalSelf AdministrationMotor ActivityAnalgesicsIntestinal AbsorptionEstradiolHeart RateEnzyme InhibitorsDrug CombinationsKineticsHemodynamicsBiotransformationAbsorptionCells, CulturedDrug Therapy, CombinationProdrugsMice, KnockoutDrug Delivery SystemsAntibodies, MonoclonalPiperidinesAnti-Inflammatory Agents, Non-SteroidalAdministration, IntravaginalGenetic VectorsBlood GlucoseCytokinesImmunohistochemistryGenetic TherapyAdministration, BuccalUnited StatesDrug SynergismAdjuvants, ImmunologicCocaineAnti-Bacterial AgentsBileEating