Influence of particle size on the adsorption and release of cephalexin and amoxicilin encapsulated in hydrotalcite-like compound

FRANCHESCOLI VELÁZQUEZ HERRERA; M. SOLEDAD LEGNOVERDE; G. FETTER; ELENA I. BASALDELLA

Congreso; XVI International Materials Research Congress; 2017

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 prove thatthese materials are capable of releasing a carried bioactive agent at aspecific rate. The main aim of these new systems is to facilitate the dosage andduration of the drug effect, in order to cause minimal disturbance to the patientby allowing the reduction of the dosage frequency.Hydrotalcite-like compounds (HT) or layered doublehydroxide are natural or synthetic anionic clays with positively charged layersbalanced by hydrated anions. HTs have characteristics such as high stability, lowtoxicity and good biocompatibility. These properties suggest that HT could be an excellentpharmaceutical excipient for drug adsorption and further controlled release.In this work the in vitro adsorption and release ofcephalexin and amoxicillin from HTs possessing different particle sizes wereevaluated. In order to have a better knowledge about the way the drug moleculesinteract with the inorganic matrix, the drug-loaded solids were studied by N2adsorption, FTIR and SEM. The adsorptionresults showed that the solids with smaller particle size have a higheradsorption 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.The adsorptioncapacity is dependent on particle size. The dimensional differences can be usedto optimize the load capacity of cephalexin and amoxicilin in the HT matrix forcontrolled delivery system