SIMULTANEOUS DETERMINATION OF PARACETAMOL AND TAPENTADOL IN TABLETS BY RATIO SPECTRA DERIVATIVE SPECTROPHOTOMETRY . International Research Journal of Pharmacy, [S. l.], v. 12, n. 9, p. 27–32, 2021. Disponível em: https://irjponline.org/index.php/irjp/article/view/202. Acesso em: 27 jul. 2026.