title: Influence of flocculating agents and structural vehicles on the physical stability and rheological behavior of nitrofurantoin suspension.
abstract: BACKGROUND
  Nitrofurantoin is a nitrofuran antibiotic that has been used for treatment of urinary tract against positive and negative bacteria.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the effect of structural vehicles and flocculating agents on physical stability and rheological behavior of nitrofurantoin suspension.
  
  
  METHODS
  To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated and their particle sizes were determined using the sieve method. Then to achieve controlled flocculation, sodium citrate and aluminum chloride were added. After choosing the suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose and Veegum were evaluated individually and in combination. In addition, the effect of sorbitol on density of continuous phase and some physical stability parameters such as sedimentation volume, degree of flocculation and ease of redispersion of the suspensions were evaluated. After incorporation of structural vehicles, the rheological properties of formulations were also determined to find their flow behavior.
  
  
  RESULTS
  According to the results, glycerin (0.2%) and sodium citrate (0.3%) had the best effect on the suspension stability as wetting and flocculating agents, respectively. Rheological properties of formulations showed pseudoplastic behavior with some degree of thixotropy.
  
  
  CONCLUSIONS
  In conclusion, the suspension containing Veegum 1%, sodium carboxy methyl cellulose 1%, glycerine 0.2%, sodium citrate 0.3% and sorbitol 20 % was chosen as the most physically stable formulation.
authors.affiliation: Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Eskandar
authors.initials: E
authors.lastname: Moghimipour
authors.affiliation: Nanotechnology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Anayatollah
authors.initials: A
authors.lastname: Salimi
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Zanjan University of Medical Science, Zanjan, IR Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Rezaee
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Balack
authors.affiliation: Nanotechnology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Handali
keywords: Nitrofurantoin; Rheology; Suspensions; Wetting Agents