Release kinetics from LDH-drug hybrids: Effect of layers stacking and drug solubility and polarity.

ROJAS DELGADO, R; JIMENEZ KAIRUZ AF; MANZO RH; GIACOMELLI, CE

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 463 p. 37 - 43

0927-7757

tThis work highlights the effect of drug solubility and polarity and solid layer stacking on the releaserate and mechanism of layered double hydroxides-drug (LDH-D) hybrids. With such a purpose, LDH-Dhybrids containing three structural related non-steroidal anti-inflammatory drugs (ibuprofen, naproxenor ketoprofen) were synthesized by a simple co-precipitation method. LDH matrixes exhibited a high drugloading capacity, even exceeding the anion exchange capacity of the solid especially with the more apolardrugs. The structure and interfacial properties of the particulate LDH-D hybrids were also dependenton the polarity of the loaded drug. Finally, the release mechanisms in neutral and acidic media werestudied with compressed LDH-D hybrids. The hybrids compression leaded to highly stacked plateletsthat caused a slower and steadier drug release rate than particulate LDH-D hybrids in all cases. In neutralmedium, the drugs were exclusively released by anion exchange with HPO42−ions and the release ratewas determined by the drug polarity. In acidic medium, weathering was the main release mechanism.However, additional processes (anion exchange, drug solubilization) were concurrent in the latter media,the overall mechanism and release rate being dependent on the drug solubility.