The synthesis and the spectroscopic characterization of a new potential drug for urinary incontinence, adosupine, is described. Adosupine and its potential synthesis impurities were analyzed by a new HPLC method that was developed with a C18 reversed-phase column. The analysis was made under isocratic conditions, with a mobile phase of acetonitrile:water (15:85, v/v). Resolution of all synthesis impurities was allowed. The method was also applied to stability studies of adosupine in solid state and in solution under different conditions. With the conditions used, only one degradation product was shown by HPLC analysis; it was isolated, characterized, and identified as the hydrolysis product of the lactam ring present in the adosupine structure.