Ratio (%) between each AUC0–4 h in vitro and AUC0–4 h in vivo (AUC0–4 h in vitro/AUC0–4 h in vivo × 100). AUC0–4 h in vitro: a in vitro fasted-state gastric followed by fasted-state intestinal conditions; and b in vitro fasted-state gastric followed by fed-state intestinal conditions. AUC0–4 h in vivo: calculated from the absorption profiles after deconvolution of the in vivo plasma profiles of Singulair® granules (4 mg) in infants (16,17,19); (grey area represents the range criteria (80–125%) set for prediction of in vivo drug performance)