Preparation of azithromycin-ion exchange resin complexes for taste-masking and controlled drug release

In order to mask the bitterness of azithromycin (AZI) and individually regulate the drug release rate to reduce gastrointestinal irritation, immediate-release AZI-Amberlite^TM IRP64/HPC and delayed-release AZI-Amberlite^TM IRP69/RS100 were prepared by modifying with hydroxypropyl cellulose (HPC) and Eudragit RS100, respectively, and further combined to achieve controlled release.The drug loading and drug utilization rate of AZI-ion exchange resin complexes were measured; the structure of AZI-ion exchange resin complexes was characterized by differential scanning calorimetry and X-ray diffraction; and the wetting humidity, odor masking effects, in vitro dissolution and release behaviors were determined.The results showed that the formation of AZI-ion exchange resin complexes changed the original crystallization state of the drug, that the 2.5% HPC-modified AZI-Amberlite^TM IRP64/HPC and the 0.5% RS100-modified AZI-Amberlite^TM IRP69/RS100 demonstrated good taste masking effect, and that their combination in the drug content ratio of 13∶67 achieved the expected drug release behavior, i.e.rapid release of AZI in the first 10 min and smooth release in the later 6 h.These results indicated that the AZI-ion exchange resin complexes prepared by surface modification and their composites could mask the bitterness of AZI and realize the flexible adjustment of drug release rate, which lays the foundation for the research and development of new AZI preparations.