Enteric-coated layered double hydroxides as a controlled release drug delivery system.

Layered double hydroxides (LDHs) or so-called anionic clays consist of cationic brucite-like layers and exchangeable interlayer anions. Because of their biocompatibility, these layered inorganic solids can be used as host materials to create drug-LDH host-guest supramolecular structures. Because of the basicity of LDHs however, LDHs as drug delivery system will be limited for use in the stomach where pH is 1.2. A core-shell material has been prepared therefore in this work. A non-steroidal anti-inflammatory drug, Fenbufen-intercalated LDHs as the core was coated with enteric polymers, Eudragit S 100 or Eudragit L 100 as a shell, giving a composite material which shows controlled release of the drug under in vitro conditions which model the passage of a material through the gastrointestinal tract.