The new version of the drug, which is Yamanouchi's best-selling product with sales of Y110 billion (€829m) in fiscal 2003, was developed using a new drug delivery technology called OCAS which improves the absorption of the active ingredient.

OCAS (oral controlled absorption system) is a once-daily oral controlled-release system which makes it possible for a drug to be absorbed from not only the upper gastrointestinal tract (including the stomach and duodenum) but also the lower GI tract (colon), from which drug absorption is usually difficult. This technology makes drugs less liable to the effects of meals than conventional capsule formulations. And improves its pharmacokinetic profile, resulting in a smoother, more regular absorption of tamsulosin over the day.

This profile should avoid peaks in drug absorption, which could be associated with side effects, while avoiding troughs in drug levels which could impair efficacy.

OCAS' is a semi-permeable hydrogel formulation that exhibits tablet gelation of more than 80 per cent within upper GI residence time. Its polymer matrix permits the oral administration of proteins and peptides, generally not possible with earlier drug delivery technologies. It was developed by Yamanouchi Pharmaceutical Technologies .

Netherlands-based Yamanouchi Europe submitted an application for the alpha blocker seeking approval for the treatment of lower urinary tract symptoms associated with BPH. The drug improves the symptoms of BPH - such as by relaxing the urethra with almost no effect on vascular smooth muscles, which affect blood pressure.