4Palma-Aguirre J A, Villalpando-Herndndez J, Novoa Heckel G,et al. Bioavailability of two oral-tablet and two oral-suspen- sion formulations of naproxen sodium/paracetamol(acetamino phen) : single-dose, randomized, open-label, two-period cross over comparisons in healthy Mexican adult subiects[J]. Clin Ther, 2009, 31(2) :399-410.