Development and validation of alternative methods by non-aqueous acid-base titration and derivative ultraviolet spectrophotometry for quantification of sildenafil in raw material and tablets. Brazilian Journal of Pharmaceutical Sciences, [S. l.], v. 53, n. 1, p. e15181-, 2017. DOI: 10.1590/s2175-97902017000115181. Disponível em: https://revistas.usp.br/bjps/article/view/131419.. Acesso em: 27 apr. 2024.