Preparation, characterization and taste-masking properties of microspheres containing azithromycin

Development of taste masking microcapsules containing azithromycin by fluid bed coating for powder for suspension and in vivo evaluation

This research aims to develop bitter taste masking microcapsules containing azithromycin by a simpler and familiar method, fluid-bed coating technology, in comparison with Zithromax®. Cores of microcapsules, azithromycin microparticles, were prepared by fluid-bed granulation, then taste-masking polymer was covered on by fluid-bed coating technique. Eudragit L100, Eudragit RL100, ethyl cellulose in single and combined with Eudragit L100, Eudragit E100 were used as taste-masking polymers. The obtained microcapsules were characterized by taste masking ability, in-vitro release, SEM, coating thickness and coating efficiency. Combination of ethyl cellulose and Eudragit E100 (3:1) in coating thickness of 45.13 ± 2.12% w/w prevent azithromycin release from microcapsules below bitter taste threshold (1.78 ± 1.17 μg/ml). Bioavailability of powders containing azithromycin microcapsules and pH modulators (50mg Na₃PO₄ and 35mg Mg(OH)₂) was not significantly different from the reference product (Zithromax®, Pfizer) in the rabbit model (p > 0.05). These results support the possibility of developing a generic product containing azithromycin.

Enhancing Dissolution Rate and Antibacterial Efficiency of Azithromycin through Drug-Drug Cocrystals with Paracetamol

Cocrystallization is a promising approach to alter physicochemical properties of active pharmaceutical ingredients (hereafter abbreviated as APIs) bearing poor profile. Nowadays pharmaceutical industries are focused on preparing drug-drug cocrystals of APIs that are often prescribed in combination therapies by physicians. Physicians normally prescribe antibiotic with an analgesic/antipyretic drug to combat several ailments in a better and more efficient way. In this work, azithromycin (AZT) and paracetamol (PCM) cocrystals were prepared in 1:1 molar ratio using slow solvent evaporation method. The cocrystals were characterized by Fourier transform infrared (FTIR), Raman spectroscopy, powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), thermo gravimetric analysis (TGA) and high-performance liquid chromatography (HPLC). Vibrational spectroscopy and DSC confirmed that both APIs interact physically and showed chemical compatibility, while PXRD pattern of the starting material and products revealed that cocrystal have in a unique crystalline phase. The degree of hydration was confirmed by TGA analysis and result indicates monohydrate cocrystal formation. The HPLC analysis confirmed equimolar ratio of AZT:PCM in the cocrystal. The in vitro dissolution rate, saturation solubility, and antimicrobial activity were evaluated for AZT dihydrate and the resulting cocrystals. The cocrystals exhibited better dissolution rate, solubility and enhanced biological activities.