Rutin and quercetin gastro-resistant microparticles obtained by spray-drying technique

Quercetin and rutin gastro-resistant microparticles were prepared by spray-drying using cellulose acetate trimellitate (CAT) or cellulose acetate phthalate (CAP) as coating polymers. The influence of parameters such as the initial organic or aqueous feed solutions and polymer/drug ratio on the particle yield, behaviour and morphology was investigated. By spray-drying 2% buffer aqueous feed solutions in different polymer/drug ratio (1:1, 3:1 and 5:1) microparticles loaded with rutin were obtained. The microsystems were characterized by scanning electron microscopy (SEM), fluorescence microscopy (FM), and differential scanning calorimetry (DSC). In vitro dissolution studies, carried out using a pH change method, showed a typical biphasic drug release trend due to the pH dependent solubility of the enteric polymers.