title: Dissolution rate and stability study of flavanone aglycones, naringenin and hesperetin, by drug delivery systems based on polyvinylpyrrolidone (PVP) nanodispersions.
abstract: OBJECTIVE
  To study the dissolution behavior, the release mechanism and the stability of nanodispersion system of aglycones with PVP.
  
  
  METHODS
  The nanodispersion system of polyvinylpyrrolidone (PVP)/naringenin-hesperetin was prepared using the solvent evaporation method. The chemical stability (compatibility) of naringenin and hesperetin in the prepared dispersions was studied under accelerated conditions for 3 months. The evaluation of physical stability was performed by X-ray diffraction analysis (XRD) and by comparing the dissolution profile before and after storage at high temperature and moisture (40 masculineC, RH 75%).
  
  
  RESULTS
  The dissolution rate of naringenin and hesperetin released was dramatically increased in the nanodispersion system of PVP/naringenin-hesperetin (80/20, w/w). The release mechanism of both flavanone aglycones was better described by the diffusion model (Higuchi model). Also it was found that the rate-limiting step that controlled the release of naringenin and hesperetin in the nanodispersion system was dissolution of the carrier (PVP).
  
  
  CONCLUSIONS
  During accelerated degradation analysis, for 3 months at high temperature and moisture, PVP nanodispersion system showed enhanced chemical compatibility and physical stability. The physical evaluation (obtained from XRD analysis) of PVP/naringenin-hesperetin (80/20, w/w) in the selected storage conditions did not show any crystallization of flavanone aglycones in the PVP nanodispersion system or any change in their release profile.
authors: Department of Pharmaceutics and Drug Control, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki, Greece. firas9@yahoo.com
authors: F I
authors: FI
authors: Kanaze
authors: E
authors: E
authors: Kokkalou
authors: I
authors: I
authors: Niopas
authors: P
authors: P
authors: Barmpalexis
authors: E
authors: E
authors: Georgarakis
authors: D
authors: D
authors: Bikiaris
mesh_terms: D002214:Capsules; D002626:Chemistry, Pharmaceutical; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry; D044950:Flavanones / Q000032:analysis / Q000737:chemistry*; D006569:Hesperidin / Q000032:analysis / Q000737:chemistry*; D006358:Hot Temperature / Q000009:adverse effects; D007700:Kinetics; D008956:Models, Chemical; D036103:Nanotechnology; D010592:Pharmaceutic Aids / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*; D012995:Solubility; D013535:Suspensions; D013607:Tablets; D013997:Time Factors; D014867:Water / Q000009:adverse effects
chemical_list: D002214:Capsules; D005079:Excipients; D044950:Flavanones; D010592:Pharmaceutic Aids; D013535:Suspensions; D013607:Tablets; D014867:Water; D006569:Hesperidin; D011205:Povidone; C005273:naringenin; C013015:hesperetin