Synthesis and characterization of layered double hydroxides consisting of essential metals for drug encapsulation

Abstract

Layered Double Hydroxides (LDHs) have characteristics that selected them as potential candidates for the encapsulation of species of pharmaceutical interest, such as biocompatibility, promoting sustained release due to its dissolution or ion exchange reaction, and increased solubility of poorly soluble substances in water. Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most studied classes of drugs associated with LDH producing hybrid materials. When NSAIDs are intercalated into LDHs, it is observed the reduction of side effects (since LDHs are potent antacids) and also an increase in the drugs bioavailability. The ability of LDHs to provide the controlled release to specific sites in the body promotes the therapeutic activity enhancing and, consequently, the intake of smaller drug amounts. This project aims to investigate the synthesis of LDHs comprising just essential metals for the body to facilitate the metabolism of the drug carrier. For this purpose will be prepared LDHs of M2+/Fe3+ composition (where M = Mg, Ca or Zn) and molar ratio equal 2. After exploring the optimum synthetic conditions for obtaining LDHs (as chloride form) with crystallographic purity, this work also proposes to intercalate the anions derived from the NSAIDs naproxen and mefenamic acid. LDHs will be obtained by one-pot reaction at constant pH from the addition of a mixed metals aqueous solution to a chloride anion solution. The isolated solid may, if necessary, undergo post-synthesis heat treatment. All synthesized materials will be characterized by structural techniques (X-ray diffraction), spectroscopic (electronic and vibrational), textural (surface area measurement, average particle size and Zeta potential), thermal (TGA-DSC-MS), and elemental analysis. (AU)