Gastro-oesophageal reflux disease is a frequently occurring condition among institutionalized patients with severe neurodevelopmental problems . Based on a limited number of studies [2, 3], the proton pump inhibitor (PPI) omeprazole is regarded as the therapy of choice in this patient population. As PPIs are acid-labile molecules, oral omeprazole dosage forms are enteric coated to protect the omeprazole until delivery and absorption in the duodenum . However, patients with severe neurodevelopmental problems often depend on a feeding tube for the administration of drugs because of oral motor dysfunction with uncoordinated and unsafe swallowing . As enteric-coated formulations should not be crushed, they cannot be administered through a feeding tube. Various alternatives for delivering omeprazole and other PPIs as a liquid formulation have been proposed. In daily practice, tube-fed patients often receive omeprazole doses either as (i) an omeprazole Multiple Unit Pellet System (MUPS®) tablet disintegrated in water (‘MUPS® formulation’), or (ii) a suspension of omeprazole in 8.4% sodium bicarbonate (‘suspension formulation’). Both of these options are recommended by the British National Formulary for Children . However, no bioavailability data for these formulations are available in tube-fed patients with severe neurodevelopmental problems. Therefore, this trial evaluated the omeprazole pharmacokinetics in tube-fed patients with severe neurodevelopmental problems after administration as a MUPS® formulation and as a suspension formulation.