Hybrid compounds for improving drugs solubility: Synthesis, physicochemical and pharmaceutical characterization of Nimesulide-LDH

Layered double hydroxides (LDHs) with their sheets structure are undoubtedly interesting inorganic hosts for
different applications, in particular for drug delivery. Nimesulide, a poorly soluble anti-inflammatory drug,
could benefit of the association with LDH to improve its low dissolution rate and thanks to natural antacid
properties of LDH to reduce the gastric irritation after its administration. In this paper, we synthesize by coprecipitation
and reconstruction methods the hybrid compound Nimesulide-Mg3Al-LDH, as demonstrated by
X-ray powder diffraction (from hydroxide layers expansion with respect to pure LDH), thermal analysis (from
the absence of drug melting point in the hybrids) and infrared spectroscopy (from the absence of stretching of
NO2 and SO2 in the hybrid, suggesting the loose of its rotational freedom into the LDH). In addition, SEM
microscopy/EDS microanalysis supported the formation of new entities. The dissolution tests demonstrate an
improvement of two times in terms of percentage of drug dissolved when nimesulide is in the form of a hybrid
compound, compared to the drug alone or a reference commercial product.