TabletsSulfonesPurinesPiperazinesPhosphodiesterase InhibitorsPhosphodiesterase 5 Inhibitors3',5'-Cyclic-GMP PhosphodiesterasesErectile DysfunctionTablets, Enteric-CoatedCyclic Nucleotide Phosphodiesterases, Type 5Chemistry, PharmaceuticalExcipientsPenile ErectionHomosexuality, MaleDrug CompoundingVasodilator AgentsMethamphetamineDelayed-Action PreparationsCyclic GMPGeorgiaTechnology, PharmaceuticalMethylcellulosePowdersSolubilityUnsafe SexHardnessAdministration, OralRisk-TakingLubricantsDosage FormsSexual BehaviorTherapeutic EquivalencyCapsulesCellulosePovidoneDrug StabilityBiological AvailabilityHardness TestsAdministration, BuccalCompressive StrengthCarboxymethylcellulose SodiumSuspensionsPolymethacrylic AcidsPharmaceutic AidsCross-Over StudiesAdministration, SublingualDrug CombinationsAcetaminophenPorosityDrug StorageDrug PackagingStearic AcidsPharmaceutical PreparationsTensile Strength