| Keywords | Avanafil-13C d5, Reference Standards, Stable Isotopes, Metabolites, Stendra- 13Cd5, Spedra- 13Cd5, 4-((3-chloro-4-methoxybenzyl)amino)-2-(2-(hydroxymethyl)pyrrolidin-1-yl)-N-(pyrimidin-2-ylmethyl)pyrimidine-5-carboxamide-13Cd5, C2213CH21D5ClN7O3 |