Dissolution kinetics and mechanism of Mg-Al layered double hydroxides: a simple approach to describe drug release in acid media.

摘要: Layered double hydroxides (LDHs) weathering in acidic media is one of the main features that affects their applications drug delivery systems. In this work, dissolution kinetics biocompatible Mg-Al LDHs was studied at different initial pH values and solid concentrations using a simple fast experimental method coupled flow injection analysis amperometric detection. A carbonate intercalated sample used to determine controlling step process mechanism. Finally, study extended an ibuprofen LDH. The obtained results showed mainly controlled by exposed area surface reactivity particles. mechanism particle described two steps: formation reactive sites hydroxyl group protonation slow detachment metal ions from surface. At strongly conditions, reaction rate dependent due equilibrium between protonated (active) deprotonated (inactive) groups. On other hand, mildly behavior also ruled attained dissolved species. solubility presented strong dependence with interlayer anion. more soluble rapidly than acetic/acetate buffer. invariant