Improving the Carprofen Solubility: Synthesis of the Zn₂Al-LDH Hybrid Compound

The development of efficient strategies for drug delivery is considerably desired. Indeed, often several issues such as the drug solubility, the control of the drug release rate, the targeted delivery of drugs, the drug bioavailability, and the minimization of secondary effects still present great obstacles. Different methodologies have been proposed, but the use of nano-hybrids compounds that combine organic and inorganic substances seems particularly promising. An interesting inorganic host is the layered double hydroxide (LDH) with a sheets structure and formula [M²⁺_1-x M³⁺_x (OH)₂](A^n-)_x/n yH₂O (M²⁺ = Zn, Mg; M³⁺ = Al; A^n- = nitrates, carbonates, chlorides). The possibility to exchange these counterions with drug molecules makes these systems ideal candidates for the drug delivery. In this article, we synthesize by co-precipitation method the hybrid compound Carprofen-Zn₂Al-LDH. Carprofen, a poorly soluble anti-inflammatory drug, could also benefit of the association with a natural antacid such as LDH, to reduce the gastric irritation after its administration. Through X-ray diffraction and Fourier-transformed infrared spectroscopy (FT-IR), we could verify the effective drug intercalation into LDH. The dissolution tests clearly demonstrate a significant improvement of the drug release rate when carprofen is in the form of hybrid compound.