title: Design and characterization of microemulsion systems for naproxen.
abstract: OBJECTIVE
  This research was aimed to formulate and characterize a microemolsion systems as a topical delivery system of naproxen for relief of symptoms of rheumatoid arthritis, osteoarthritis and treatment of dysmenorrheal.
  
  
  METHODS
  ME formulations prepared by mixing of appropriate amount of surfactant including Tween 80 and Span 80, co-surfactant such as propylene glycol (PG) and oil phase including Labrafac PG - transcutol P (10:1 ratio). The prepared microemolsions were evaluated regarding their particle size, zeta potential, conductivity, stability, viscosity, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), refractory index (RI) and pH.
  
  
  RESULTS
  The mean droplets size of microemulsion formulation were in the range of 7.03 to 79.8 nm, and its refractory index (RI) and pH were 1.45 and 6.75, respectively. Viscosity range was 253.73- 802.63cps. Drug release profile showed that 26.15% of the drug released in the first 24 hours of experiment. Also, Hexagonal and bicontinuous structures were seen in the SEM photograph of the microemulsions.
  
  
  CONCLUSIONS
  characterization, physicochemical properties and in vitro release were dependent upon the contents of S/C ratio, water and, oil phase percentage in formulations. Also, ME-6 may be preferable for topical naproxen formulation.
authors: Nanotechnology Research Center, Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors: Eskandar
authors: E
authors: Moghimipour
authors: Anayatollah
authors: A
authors: Salimi
authors: Soroosh
authors: S
authors: Eftekhari
keywords: Characterization; Microemulsion; Naproxen; Phase Diagram