New oral system for timing-release of drugs.

Polymeric barriers applied by compression have already been used to control drug release rate from matrix tablets. In this paper, polymeric barrier layers, used to prepare and develop a new device able to release the drug after a programmable period of time, are described. Some matrix core formulations, containing Trapidil or Sodium Diclofenac as a model drug, were dry-coated using either a swellable or an erodible shell. This coating prevents drug release from the core until the polymeric layer is not completely eroded or swollen. The time-lag can be modified by changing the barrier formulation and/or the coating thickness. Also drug release profiles (release rate and kinetics), can be widely modified changing the barrier layer characteristics.