title: Quercetin solid lipid microparticles: a flavonoid for inhalation lung delivery.
abstract: OBJECTIVE
  The aim of the present work was to develop solid lipid microparticles (SLMs), as dry powders containing quercetin for direct administration to the lung.
  
  
  METHODS
  Quercetin microparticles were prepared by o/w emulsification via a phase inversion technique, using tristearin as the lipid component and phosphatidylcholine as an emulsifier. The quercetin SLMs were characterised for morphology, drug loading (15.5%±0.6, which corresponded to an encapsulation efficiency of 71.4%), particle size distribution, response to humidity, crystallinity, thermal behaviour and in vitro respirable fraction. Furthermore, the toxicity and the in vitro transport of the SLMs on an air liquid interface model of the Calu-3 cell line were also investigated using a modified twin-stage impinger apparatus.
  
  
  RESULTS
  Results showed that quercetin SLMs could be formulated as dry powder suitable for inhalation drug delivery (20.5±3.3% fine particle fraction ≤4.46μm) that was absorbed, via a linear kinetic model across the Calu-3 monolayer (22.32±1.51% over 4h). In addition, quercetin SLMs were shown to be non-toxic at the concentrations investigated. Interestingly, no apical to basolateral transport of the micronised quercetin was observed over the period of study.
  
  
  CONCLUSIONS
  These observations suggest quercetin diffusion was enhanced by the presence of the lipid/emulsifying excipients in the SLMs; however further studies are necessary to elucidate the exact mechanisms.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara 17, 44121 Ferrara, Italy.
authors.forename: Santo
authors.initials: S
authors.lastname: Scalia
authors.forename: Mehra
authors.initials: M
authors.lastname: Haghi
authors.forename: Vanessa
authors.initials: V
authors.lastname: Losi
authors.forename: Valentina
authors.initials: V
authors.lastname: Trotta
authors.forename: Paul M
authors.initials: PM
authors.lastname: Young
authors.forename: Daniela
authors.initials: D
authors.lastname: Traini
mesh_terms: D000280:Administration, Inhalation; D000975:Antioxidants / Q000008:administration & dosage* / Q000737:chemistry; D001692:Biological Transport; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems; D058995:Dry Powder Inhalers; D006801:Humans; D008168:Lung / Q000378:metabolism; D011794:Quercetin / Q000008:administration & dosage* / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry
chemical_list: D000975:Antioxidants; D014280:Triglycerides; D011794:Quercetin; C022618:tristearin
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