Synthesis and release behavior of layered double hydroxides – carbamazepine composites

Abstract

Carbamazepine (CBZ) was incorporated into Layered Double Hydroxides (LDH) to be used as controlled drug delivery in solid tumors. CBZ has a formal charge of 0, which implies a challenge to be incorporated in the anionic clay. Aiming to overcome this problem, CBZ was first incorporated in micelles of sodium cholate (SC), a surfactant with negative charge. CBZ in SC micelles and, for comparison, free CBZ were incorporated in LDH by reconstruction method. It was found that resultant nano-composites had similar CBZ encapsulation efficiency, around 75 %, but drug release in simulated body fluid (pH 7.4) and acetate buffer (pH 4.8) was efficient only with the LDH-CBZ sample. CBZ dimensions were measured with Chem3D and, according to the basal spacing obtained from X rays patterns, it can arrange as monolayer with the long axis parallel to the LDH layers. Fourier Transform Infrared Spectroscopy confirmed the incorporation of the drug. Thermogravimetric analyses showed and enhanced thermal stability for CBZ. These results have interesting implications since they increase the spectrum of LDH application as controlled drug delivery to a large number of non-ionic drugs, without the addition of other components.