title: Development and characterization of solid dispersion of piroxicam for improvement of dissolution rate using hydrophilic carriers.
abstract: BACKGROUND
  The main objective of this study was preparation and characterization of solid dispersion of piroxicam to enhance its dissolution rate.
  
  
  METHODS
  Solid dispersion formulations with different carriers including crospovidone, microcrystalline cellulose, Elaeagnus angustifolia fruit powder, with different drug to carrier ratios were prepared employing cogrinding method. Dissolution study of the piroxicam powders, physical mixtures and solid dispersions was performed in simulated gastric fluid and simulated intestinal fluid using USP Apparatus type II. The physical characterization of formulations were analyzed using powder X ray diffraction (PXRD), particle size analyzer and differential scanning calorimetry (DSC). Interactions between the drug and carriers were evaluated by Fourier transform infrared (FT-IR) spectroscopic method.
  
  
  RESULTS
  It was revealed that all of three carriers increase the dissolution rate of piroxicam from physical mixtures and especially in solid dispersions compared to piroxicam pure and treated powders. PXRD and DSC results confirmed the reduction of crystalline form of piroxicam. FT-IR analysis did not show any physicochemical interaction between drug and carriers in the solid dispersion formulations.
  
  
  CONCLUSIONS
  Dissolution rate was dependent on the type and ratio of drug to carrier as well as pH of dissolution medium. Dissolution data of formulations were fitted well into the linear Weibull as well as non-linear logistic and suggested models.
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Science, Tabriz, Iran ; Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Barzegar-Jalali
authors.affiliation: Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran ; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran ; Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Ghanbarzadeh
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Science, Tabriz, Iran ; Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran ; Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Khosro
authors.initials: K
authors.lastname: Adibkia
authors.affiliation: Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran ; Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Valizadeh
authors.affiliation: Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran.
authors.forename: Siamak
authors.initials: S
authors.lastname: Bibak
authors.affiliation: School of Pharmacy, Kermanshah University of Medical Science, Kermanshah, Iran.
authors.forename: Ghobad
authors.initials: G
authors.lastname: Mohammadi
authors.affiliation: Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Siahi-Shadbad
keywords: Cogrinding; Dissolution rate; Piroxicam; Solid dispersion