Authors: V.R.R. Cunha, P.A.D. Petersen, H.M. Petrilli, V.R.L. Constantino
Affilation: University of Sao Paulo, Brazil
Pages: 145 - 146
Keywords: layered double hydroxide, lipoic acid, drug delivery systems
Layered Double Hydroxides (LDHs) are well known inorganic carriers which have been explored during the development of new materials for medicinal and pharmacological applications. The solubility and chemical stability of guest species can be increased when intercalated between LDH layers. LDHs can support the release of intercalated bioactive species through ion exchange reactions and/or chemical processes mediated by changes in pH. In this study, synthetic routes and experimental parameters were determined for the confinement of the anionic form of lipoic acid (abbreviated Lip), a natural substance which displays antioxidant activity, and which can be used for the Alzheimer disease and Parkinson's treatment. The inorganic carriers containing the bioactive species were synthesized by the co-precipitation method, using molar ratios of M2+/ Al3+ = 2 and Lip/Al3+ = 1. Samples were labeled as M2AlLip.y, where M can either mean Mg2+ or Zn2+, and y denotes one of the following drying processes: (i) lyophilization (lyo) and (ii) room temperature with reduced pressure in a dessicator (des). XRD patterns of all isolated LDH-lipoate materials indicate the intercalation of lipoate anions in the interlayer region (basal spacings equal to 2.26 nm for Mg2AlLipdes, 2.19 nm for Zn2AlLip.lyo, and 2.24 nm for Zn2AlLip.des).