Ciprofloxacin in Layered Double Hydroxides: Looking for the Best Synthesis Method

Abstract

It is important to develop new methods of release to improve pharmacokinetic parameters of drugs, especially antibiotics, whose plasmatic concentration is determinant to ensure an effective treatment. Layered double hydroxides (LDH) are inorganic and biocompatible materials with high drug intercalation capacity and release properties that can be tuned by controlling the pH value. These materials can be an excellent choice to achieve a sustained release and an optimal drug concentration in plasm. In this work, LDH were synthesized with intercalated ciprofloxacin (CIP) by three different methods: coprecipitation, reconstruction and ion exchange. LDH-CIP complexes were characterized by XRD, TG-DSC, TEM, SEM, FTIR, electrophoretic mobilities, and drug release and dissolution kinetics in NaCl solutions and under physiological conditions. The coprecipitation and reconstruction methods lead to the formation of ill-defined products, whereas the ion exchange method rendered the best intercalation results. CIP release was controlled by dissolution at pH<3 and by desorption and ion exchange at intermediate and high pH. In comparison with a commercial formulation, the LDH-CIP complex prepared by ion exchange presented a slower release profile. The fast dissolution at gastric pH raises the need of developing some type of coating for protecting LDH materials.