Fluorescent drug-containing hydrotalcite-like compound for monitoring drug release

Abstract

A novel fluorescent drug-containing layered double hydroxide (MgAlZn-Asp-LDH) was prepared for the first time by the coprecipitation method with aspirin (Asp) used as the model drug. Magnesium (II) was partially replaced by zinc (II) in the hydrotalcite-like layers, and the drug, aspirin (Asp), was dispersed into the interlayer region; Zn 2+ ion in the layers was coordinated with the acetylsalicylate among the interlayer region, making a blue-fluorescent aspirin-containing layered double hydroxide. The obtained sample was tested as a drug carrier by investigating its drug-storage/release properties. X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR spectroscopy, X-ray photo-electron spectroscopy (XPS), thermogravimetry, differential-scanning calorimeter (TG-DSC), and photoluminescence (PL) spectra were used to characterize the structural, morphological, and optical properties of the resulting sample. The Asp-loaded layered double hydroxide system shows blue luminescence of zinc acetylsalicylate under UV irradiation and controlled release of Asp. In addition, the emission intensity of the system varies with the released amount of Asp, and thus drug release can be easily tracked and monitored by the change in luminescence intensity. The system provides a promising candidate for application in the drug delivery and disease therapy fields.