Fabrication of Porous Microspheres of Azithromycin, Incorporating Different Porogens

Abstract

Several antibiotics loaded nebulized formulations allow high local concentrations and a decreased risk of systemic toxicity but this formulation require time-consuming hygienic procedures for administration several times a day. An innovative way to increase drug product stability, patient comfort, and therapeutic effectiveness is to formulate an easily administered sustained-release, biodegradable, and biocompatible porous microspheres. Here the Ionotropic Gelation method has been opted for the preparation of a porous microsphere loaded with Azithromycin by inclusion of different porogens. The structural morphology of porous microspheres was investigated by Scanning Electron Microscopy. Microspheres were in the range of 600 -900 µm. with the pores in the size of
2-15µm.
Among the three porogens used, NaHCO3 showed the maximum porosity of almost 10%, whereas it was 4.9 and 6 for Sucrose and NaCl respectively. Micromeritics properties of porous microspheres were found to be satisfactory in accordance with their flow properties. In Drug release profile it was observed that after 8 hours 65%,57% and 53% drug was released from porous microspheres using NaHCO3, NaCl and sucrose as porogens respectively. To ascertain the drug release mechanism and release rate, data of all the formulations were fitted to Zero order, Higuchi Matrix, Korsmeyer Peppas model to explain the kinetics. The dug was released in a controlled way and the pattern indicated that they obeyed Higuchi kinetics. The value of release exponent ‘n’ calculated for all the formulations indicates that the formulations released drug in non Fickian (anomalous) release mechanism (n> 0.5) i.e., erosion followed by diffusion.