title: Anti-bacterial performance of azithromycin nanoparticles as colloidal drug delivery system against different gram-negative and gram-positive bacteria.
abstract: OBJECTIVE
  Azithromycin (AZI) is a new macrolide antibiotic with a better activity against intracellular gram negative bacteria in comparison with Erythromycin. The purpose of this research was to prepare AZI nanoparticles (NPs) using PLGA polymer and to compare the effectiveness of prepared nanoparticles with untreated AZI solution.
  
  
  METHODS
  AZI NPs were prepared by Modified Quasi-Emulsion Solvent Diffusion method. The antibacterial activities of prepared NPs in comparison with AZI solution were assayed against indicator bacteria of Escherichia coli (PTCC 1330), Haemophilus influenzae (PTCC 1623) and Streptococcus pneumoniae (PTCC 1240) using agar well diffusion. Inhibition zone diameters (IZD) of nano-formulation were compared to the corresponding untreated AZI. Mean Inhibitory Concentration (MIC) values of AZI were also determined using serial dilution method in nutrient broth medium.
  
  
  RESULTS
  Mean IZD of nano-formulations for all indicator bacteria were significantly higher than that of untreated AZI (P<0.01). The enhanced antibacterial efficacy was more dominant in the gram positive species. The MIC values of NPs against the tested bacteria were reduced 8 times in comparison to those of untreated AZI.
  
  
  CONCLUSIONS
  These results indicated an improved potency of AZI NPs which could be attributed to the modified surface characteristics as well as increased drug adsorption and uptake.
authors: Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. ; Students Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Morteza
authors: M
authors: Azhdarzadeh
authors: Farzaneh
authors: F
authors: Lotfipour
authors: Parvin
authors: P
authors: Zakeri-Milani
authors: Ghobad
authors: G
authors: Mohammadi
authors: Hadi
authors: H
authors: Valizadeh
keywords: Azithromycin; Minimum inhibitory concentration; Modified quasi emulsion solvent- diffusion; Nanoparticle; PLGA