Investigation of the effects of some process variables on the Azithromycin Microencapsulation by the Quasi-Emulsion Solvent Evaporation Method

Abstract

The aim of the present work was to identify the optimum formulation parameters required to achieve a maximum production yield and entrapment efficacy for Azithromycin-loaded Ethylcellulose microparticles for taste masking of Azithromycin (AZI). Quasi-emulsion solvent evaporation method was employed using Ethylcellulose. Several factors that influence the microparticles such as polymer-to-drug ratio, the inner phase volume (DCM), and the emulsifying agent concentration (PVA) were studied to determine their effects on the production yield, entrapment efficiency, and particle size of microparticle formulations. The formula F3 that provided the highest yield and entrapment efficiency (66.6±0.3%, 86.42±0.05% respectively) was evaluated using Scanning electron microscopy (SEM), Fourier transform infrared (FT‑IR), and Differential scanning calorimetry (DSC). Taste masking assessment performed in vitro. FT‑IR study showed that there was no interaction occurring between azithromycin and ethylcellulose. DSC confirmed the conversion of azithromycin from crystalline phase to amorphous phase and entrapped inside the microparticles. SEM micrographs revealed that microparticles were spherical in shape with a porous nature, where no drug crystals on the surface could be observed, indicating an encapsulation of AZI inside the polymeric matrix. In vitro, the taste assessment revealed no azithromycin release in salvia pH which could effectively mask the bitter taste of AZI.