CONICET | Buscador de Institutos y Recursos Humanos

The use ofnanotechnology in medicine and more specifically in drug delivery systems isset to spread rapidly. Several drug delivery systems recently studied proposethe use of porous solids as drug carriers. Such studies were intended to provethat these materials are capable of releasing a carried bioactive agent at aspecific rate. The main aim of these new systems is to facilitate the dosageand duration of the drug effect, in order to cause minimal disturbance to thepatient by allowing the reduction of the dosage frequency. Hydrotalcite-likecompounds (HT) or layered double hydroxide are natural or synthetic anionicclays with positively charged layers balanced by hydrated anions. HTs havecharacteristics such as high stability, low toxicity and good biocompatibility.These properties suggest that HT could be an excellent pharmaceutical excipientfor drug adsorption and further controlled release. Inthis work the in vitro adsorption and release of cephalexin and amoxicillinfrom HTs possessing different particle sizes were evaluated. In order to have abetter knowledge about the way the drug molecules interact with the inorganicmatrix, the drug-loaded solids were studied by N2 adsorption, FTIR and SEM. Theadsorption results showed that the solids with smaller particle size have ahigher adsorption capacity due to the decrease of diffusional path tortuosity.Additionally, SEM morphologies of HT before and after drug adsorption showed nochanges. Encapsulated antibiotics preserved its original structure, as observedby FTIR spectroscopy analysis. A diminution in the particle size also altersthe amount of drug released. HTs with smaller particle size favor the drugrelease. Theadsorption capacity is dependent on particle size. The dimensional differencescan be used to optimize the load capacity of cephalexin and amoxicilin in theHT matrix for controlled delivery system.