New Emerging Inorganic–Organic Systems for Drug-Delivery: Hydroxyapatite@Furosemide Hybrids

In the pharmaceutical market, the need to find effective systems for the efficient release of poorly bioavailable drugs is a forefront topic. The inorganic–organic hybrid materials have been recognized as one of the most promising systems. In this paper, we developed new Hydroxypapatite@Furosemide hybrids with improved dissolution rates in different media with respect to the drug alone. The hybrids formation was demonstrated by SEM/EDS measurements (showing homogeneous distribution of the elements) and FT-IR spectroscopy. The drug was adsorbed onto hydroxyapatite surfaces in amorphous form, as demonstrated by XRPD and its thermal stability was improved due to the absence, in the hybrids, of melting and decomposition peaks typical of the drug. The Sr substitution on Ca sites in hydroxyapatite allows increasing the surface area and pore volume, foreseeing a high capacity of drug loading. The dissolution tests of the hybrid compounds show dissolution rates much faster than the drug alone in different fluids, and also their solubility and wetting ability is improved in comparison to furosemide alone.