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dc.contributor.authorSimovic, Spomenka
dc.contributor.authorHeard, Peter
dc.contributor.authorHui, He
dc.contributor.authorSong, Yunmei
dc.contributor.authorPeddie, Frank
dc.contributor.authorDavey, Andrew K
dc.contributor.authorLewis, Andrew
dc.contributor.authorRades, Thomas
dc.contributor.authorPrestidge, Clive A
dc.date.accessioned2017-05-03T14:05:57Z
dc.date.available2017-05-03T14:05:57Z
dc.date.issued2009
dc.date.modified2011-08-31T07:18:21Z
dc.identifier.issn1543-8384
dc.identifier.doi10.1021/mp900063t
dc.identifier.urihttp://hdl.handle.net/10072/40526
dc.description.abstractWe report on the fabrication and characterization of dry hybrid lipid-silica nanoparticle based microcapsules with an internal porous matrix structure for encapsulation of poorly soluble drugs, and their delivery properties (in vitro release and lipolysis and in vivo pharmacokinetics demonstrated for indomethacin as a model drug). Microcapsules were prepared by spray drying of Pickering o/w emulsions containing either negatively or positively charged lipophilic surfactant in the oil phase and hydrophilic silica nanoparticles in the aqueous phase. Effective microcapsule formation is critically dependent on the interfacial structure of the nanoparticle containing emulsions, which are in turn controlled by the surfactant charge and the nanoparticle to lipid ratio. Microcapsules (containing 50-85% oil) can be prepared with 10 times fewer silica nanoparticles when a droplet-nanoparticle charge neutralizing mechanism is operative. Cross-sectional SEM imaging has confirmed the internal porous matrix structure and identified pore sizes in the range 20-100 nm, which is in agreement with BET average pore diameters determined from gas adsorption experiments. Differential scanning calorimetry and X-ray diffraction analysis have confirmed that the model drug indomethacin remains in a noncrystalline form during storage under accelerated conditions (40 ì 75% RH). Dissolution studies revealed a 2-5-fold increase in dissolution efficiency and significantly reduced the time taken to achieve 50% of drug dissolution values (=2- or 10-fold) for indomethacin formulated as microcapsules in comparison to o/w submicron emulsions and pure drug, respectively. Orally dosed in vivo studies in rats have confirmed superior pharmacokinetics for the microcapsules. Specifically, the fasted state absolute bioavailability (F) was statistically higher (93.07 ᠵ.09%) (p < 0.05) than for aqueous suspension (53.54 ᠲ.91%) and o/w submicron emulsion (64.57 ᠲ.11%). The microcapsules also showed the highest maximum plasma concentration (Cmax) among the investigated formulations (p < 0.05). In vitro lipolysis showed statistically higher (p < 0.05) fasted digestion (75.8% after 5 min) and drug solubilization (98% after 5 min) in digestive products for microcapsules than o/w emulsions. The hybrid lipid-silica microcapsules improve oral absorption by enhancing lipolysis and drug dissolution.
dc.description.peerreviewedYes
dc.description.publicationstatusYes
dc.languageEnglish
dc.language.isoeng
dc.publisherAmerican Chemical Society
dc.publisher.placeUnited States
dc.relation.ispartofstudentpublicationN
dc.relation.ispartofpagefrom861
dc.relation.ispartofpageto872
dc.relation.ispartofissue3
dc.relation.ispartofjournalMolecular Pharmaceutics
dc.relation.ispartofvolume6
dc.rights.retentionY
dc.subject.fieldofresearchMacromolecular and materials chemistry
dc.subject.fieldofresearchPharmacology and pharmaceutical sciences
dc.subject.fieldofresearchPharmaceutical sciences
dc.subject.fieldofresearchcode3403
dc.subject.fieldofresearchcode3214
dc.subject.fieldofresearchcode321405
dc.titleDry Hybrid Lipid−Silica Microcapsules Engineered from Submicron Lipid Droplets and Nanoparticles as a Novel Delivery System for Poorly Soluble Drugs
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
gro.rights.copyrightSelf-archiving of the author-manuscript version is not yet supported by this journal. Please refer to the journal link for access to the definitive, published version or contact the author[s] for more information.
gro.date.issued2009
gro.hasfulltextNo Full Text
gro.griffith.authorDavey, Andrew


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