LIPOSOMAL INTRAOCULAR DRUG DELIVERY SYSTEMS.ppsx

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LIPOSOMALINTRAOCULAR DDS

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INTRODUCTION
Millionsofpeopleworldwidesuffersfromseveraleye
diseaseswhichthreatensight,asglaucoma,cataract,
diabeticretinopathyanddryeyes.
Thedefensemechanismsobservedintheeye(epithelium,
tearflowandblinkingreflex)hamperthedrugpenetration
intodeeperlayersoftheeye.
Thepreviouslymentioneddiseaseswiththosechallenges
forcedresearcherstodevelopnewtechniquesindrug
deliverysystemstoovercomethesechallenges,oneof

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WHAT IS LIPOSOME?
Liposomeisahollow
nanospherecomposedof
lipidbilayers(phospholipids,
lipidconjugatedpolymers,
andcholesterol)thatcan
entrapbothlipophilicand
hydrophilic drug
molecules.

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LIPOSOMESVS MICELLES
Liposomesarecomposedoflipidbilayersseparatingan
aqueousinternalcompartmentfromthebulkaqueous
phase,whilemicellesareclosedlipidmonolayerswitha
fattyacidcoreandpolarsurface.
Liposomesareformedmainlybyphospholipidmolecules
suchascholesterol,whilemicellesareformedbysurfactant
moleculessuchasdetergentsoremulsifiers.
Liposom
e
Micell
e

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CHARACTERISTICS OF LIPOSOMES
Bilayerstructure:amphiphilicmolecules,typically
phospholipids,whichhaveahydrophilicheadand
hydrophobictail.Thestructureallowsthemtoencapsulate
hydrophilicandhydrophobicsubstances.
Biocompatibility:safeforuseinbiologicalsystems.They
arewell-toleratedbythebodyandhavelowtoxicity.
Versatility:Theycanencapsulateawiderangeofdrugs,
molecules,andcompounds.Theyaresuitablefordelivering
therapeuticdrugs,vaccines,geneticmaterial,andvarious

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…CHARACTERISTICS OF LIPOSOMES
Controlledrelease:canbedesignedtoprovidecontrolled
andsustaineddrugrelease.Thiscanimprovethe
therapeuticeffectandreducethefrequentdosing.
Targeteddelivery:Surfacemodificationscanbemadeto
liposomestoenhancetheirspecificityforparticularcells,
tissues,ororgans.
Protectionofencapsulatedsubstances:provide
protectiontoencapsulatedsubstancesfromdegradation,
enzymaticaction,andenvironmentalfactorssuchaslight

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…CHARACTERISTICS OF LIPOSOMES
Controlledrelease:canbedesignedtoprovidecontrolled
orsustainedrelease,&soimprovetheeffectandreducethe
frequentdosing.
Variabilityinsize:canbeengineeredtohaveaspecific
sizerange,whichimpactstheirdrugreleasepropertiesand
biodistribution.
EnhancedSolubility:enhancethesolubilityofhydrophobic
drugs,makingthemmorebioavailableandeffective.

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APPLICATIONS OF LIPOSOMES INOCULAR DDS
INTRAVITREALAPPLICATION
Formulatedlipidprodrugofganciclovirintoliposomesas
antiviraltreatmentagainstherpessimplexvirus.Intravitreal
injectionwith0.2nMintravitrealconcentrationwasthemost
effectivewithoutcausinganysideeffectsofvitreousclarity
orcataractsdevelopmentintheeye.Moreover,this
formulationprovidedcompleteretinalprotectionevenafter
simultaneousintravitrealinjection.

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…APPLICATIONS OF LIPOSOMES INOCULAR DDS
TOPICALAPPLICATION
Topicaladministrationofchitosan-coatedliposomes
(chitosomes)improvesprecornealretentionandalsoslows
downdrugmetabolismattheprecornealepithelialsurface.
Cationicliposomescontainingherpessimplexvirus(HSV)
antigenswereproposedaspotentialcarriers,intheformof
aperiocularvaccine,toprotectagainstsubsequentHSV-1
ocularchallenges.

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…APPLICATIONS OF LIPOSOMES INOCULAR DDS
SUBCONJUNCTIVALAPPLICATION
Absorptionrateofliposome-boundlowmolecularweight
heparin(LMWH)wasinvestigatedaftersubconjunctival
injectioninthetreatmentofsubconjunctivalhemorrhage.
Lowconcentrationofliposome-boundLMWHwasobserved
ascomparedtothefreeLMWHintheintraocularregions
(aqueousandvitreous).Moreover,lowersystemiclevelof
LMWHwasnotedaftersubconjunctivalinjection

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THANK YOU
BY: HOSSAM KHAYYAL