In Situ Synthesis, Encapsulation in Arabinoxylan and Release Kinetics of Microcrystalline Copper(II)-Aspirinate

Abstract

Microcrystalline copper(II)-aspirinate was synthesized in situ by allowing copper(II) acetate monohydrate and aspirin to react in pre-swollen arabinoxylan (AX) from ispaghula (Plantago ovata) husk in aqueous medium. The method resulted in formation of microcrystalline (< 40 mm) copper(II)-aspiri nate dispersed in AX matrix. The product was characterized by microscopic FT-IR spectroscopy, pXRD, scanning electron microscopy and atomic force microscopy. The AX-encapsulated copper(II)-aspirinate exhibited a smooth release profile of aspirin over 8 h following Korsmeyer-Peppas model for swellable polymer films in alkaline medium. The release was of Fickian type with n = 0.5. The release rate appeared to follow the order: alkaline pH > distilled water > acidic pH suggesting the pH-dependent release from AX. These profiles were highly sustained as compared with those of the naked drug