Preparation and in vitro evaluation for amorphous solid dispersion of azithromycin

The present work aimed to formulate azithromycin as amorphous solid dispersion for bitter taste masking, improving stability in an acid medium, and reducing the side effects. Solid dispersion with pH-dependent polymers (Eudragit L100, Eudragit S100) were prepared by the solvent evaporation method. The influence of polymer and drug-polymer ratio on production yields and loading% were evaluated. The F2 (AZI: L100 1:4) that gave the highest yield and loading (96 ± 0.3, 92.3 ± 0.07 respectively) was examined using Scanning electron microscopy (SEM), Fourier transform infrared (FT‑IR), Powder X‑ray diffraction (PXRD) and Differential scanning calorimetry (DSC). Taste masking evaluation was performed in vitro by two methods (in vitro drug release at saliva pH, and comparison of bitter taste threshold with the optimal formulation). (FT‑IR) study displayed that there was no interaction happen between azithromycin and Eudragit L100. DSC and PXRD emphasized the conversion of azithromycin from the crystalline to the amorphous form and entrapped inside the solid dispersion. In vitro, taste assessment detected no azithromycin release in salvia pH (6.8) within 5 min and minimal release in pH 1.2 which indicate this method might be a suitable approach to achieve taste masking of AZI and to improve stability in acid conditions.