ABSTRACT
The appreciation that oesophageal transit of formulations could be the first stumbling block that orally administered solid drug formulations could encounter appears to stem from the introduction of wax-based matrix tablets of potassium chloride produced in the 1960’s1. Since this time there have been numerous reports in the literature of drugs that have the potential to cause damage to the mucosa. Although most of the injuries were selflimiting, with symptoms such as retrosternal pain and dysphagia, there were occasional instances of serious complications such as perforation and haemorrhage leading to death. Another significant consequence of retention of a formulation in the oesophagus is that it can reduce or delay absorption of the drug.
