Layered solids as a ''molecular container'' for pharmaceutical agents: L-tyrosine-intercalated layered double hydroxides

L-Tyrosine has been intercalated into NiAl, MgAl and ZnAl layered double hydroxides by coprecipitation. The structure and composition of the intercalated materials have been characterized by X-ray diffraction (XRD) and elemental analysis. It is found that intercalation can inhibit racemization of L- tyrosine under the influence of sunlight, high temperature or ultraviolet light. Therefore, this layered material may have potential application as a "molecular container'' for storing or transporting unstable chiral biomolecules or pharmaceutical agents. In addition, the thermal decomposition of the L- tyrosine intercalated NiAl-LDH has been investigated in detail by means of in situ HT-XRD, in situ FT-IR and TG-DTA. Loss of interlayer water occurs between room temperature and 150 degreesC while decomposition of intercalated L- tyrosine and dehydroxylation of the host layers begin at about 250 degreesC and 300 degreesC respectively.