shiva(nanoparticles)

DEPT OF PHARMACEUTICSDEPT OF PHARMACEUTICS 11

NANOPARTICLESNANOPARTICLES (ULTRAFINE COLLOIDAL CAPSULES)(ULTRAFINE COLLOIDAL CAPSULES)

BY…..BY….. SHIVA KUMAR.YSHIVA KUMAR.Y M.PHARMACY(1M.PHARMACY(1STST Y) Y) DEPT:PHARMACEUTICSDEPT:PHARMACEUTICS KLE UNIVERSITYKLE UNIVERSITY BELGAUM.BELGAUM.


CONTENTS….CONTENTS….• DEFINITION.DEFINITION.• INTRODUCTION.INTRODUCTION.• NATURAL HYDROPHILIC POLYMERS.NATURAL HYDROPHILIC POLYMERS.• SYTHETIC HYDROPHOBIC POLYMERS.SYTHETIC HYDROPHOBIC POLYMERS.• N.P PREPARATION.N.P PREPARATION.• NOVEL NANOPARTICULATE SYSTEM.NOVEL NANOPARTICULATE SYSTEM.• PH’CEUTICAL ASPECTS OF N.P.PH’CEUTICAL ASPECTS OF N.P.• CHARECTERIZATION OF N.P.CHARECTERIZATION OF N.P.• IN VITRO RELEASE.IN VITRO RELEASE.• THERAPEUTIC APPLICATIONS OF N.P.THERAPEUTIC APPLICATIONS OF N.P.• REFERENCES.REFERENCES.


Definition :Definition :• Polymeric nanoparticles can be Polymeric nanoparticles can be

defind as submicronic (size < 1 defind as submicronic (size < 1 μμm) m) colloidal carriers.colloidal carriers.

(or)(or)

• Nanoparticles or nanocapsules are Nanoparticles or nanocapsules are vesicular system in which the central vesicular system in which the central valume surrounded by continuous valume surrounded by continuous polymeric sheath.polymeric sheath.


Introduction :Introduction :• These n.p are having nanometer size rang These n.p are having nanometer size rang

10 -1000 nm.10 -1000 nm.• These n.p are more stable then liposomes These n.p are more stable then liposomes

in biological fluids and storage due to their in biological fluids and storage due to their polymeric nature.polymeric nature.

• Nanospheres consists of a dense polymeric Nanospheres consists of a dense polymeric matrix, in which the drug can be dispersed.matrix, in which the drug can be dispersed.

• Nanocapsules having liquid core Nanocapsules having liquid core surrounded by polymeric shell.surrounded by polymeric shell.

• Polymeric n.p cannot be sterilized by Polymeric n.p cannot be sterilized by autoclaving .They have been sterilized by autoclaving .They have been sterilized by γγ –radiation.–radiation.


Natural hydrophilic Natural hydrophilic polymerspolymers Proteins Proteins polysaccharidespolysaccharides

GelatinGelatin

AlbuminAlbumin

LectinsLectins

LeguminLegumin

vicilin vicilin

AlginateAlginate

DaxtranDaxtran

ChitosanChitosan

AgaroseAgarose

PullulanPullulan


Synthetic hydrophobic Synthetic hydrophobic polymerspolymersThe polymers used are either pre-The polymers used are either pre-polymerized or synthesized before (first polymerized or synthesized before (first group) or during the (second group) process group) or during the (second group) process of n.p preparation.of n.p preparation. Pre-polymerizedPre-polymerized Polymerized in Polymerized in

processprocess

Poly (lactic acid) Poly (lactic acid) (PLA)(PLA)

Poly (lactide-co-Poly (lactide-co-glycolide) (PLGA)glycolide) (PLGA)

polystyrenepolystyrene

Poly Poly (isobutylcyanoacrylat(isobutylcyanoacrylates) (PICA)es) (PICA)

Poly Poly (butylcyanoacrylate) (butylcyanoacrylate) (PBCA)(PBCA)

PolyhexylcyanoacrylaPolyhexylcyanoacrylatestes


N.P preparation N.P preparation 1.1. Cross linking of amphiphilic Cross linking of amphiphilic

macromoleculesmacromolecules• The technique of their preparation The technique of their preparation

involves firstly , the aggregation of involves firstly , the aggregation of amphiphile ,followed by further amphiphile ,followed by further stabilization either by heat denaturation stabilization either by heat denaturation or chemical cross- linking.or chemical cross- linking.

• These process may occur in a biphasic These process may occur in a biphasic o/w or w/o type dispersed system.o/w or w/o type dispersed system.


Cross linking in w/o emulsionCross linking in w/o emulsion


Phase separation in aqueous Phase separation in aqueous medium (desolvation)medium (desolvation)• The protein or polysaccharide from an aqueous The protein or polysaccharide from an aqueous

phase can be desolvated by Pphase can be desolvated by PHH changes or change changes or change in temp. or by adding some appropriate counter in temp. or by adding some appropriate counter ions.ions.

• The method having three stepsThe method having three steps Protein dissolution. Protein dissolution. Protein aggregation. Protein aggregation. • Protein deaggregation. Protein deaggregation. • The aggregation size should be maintained by The aggregation size should be maintained by

appropriate level of desolvation & resolvation.appropriate level of desolvation & resolvation.• Cross –linking agent (glutaraldehyde) , desolvating Cross –linking agent (glutaraldehyde) , desolvating

or deaggregating agent (ethanol , isopropanol , or deaggregating agent (ethanol , isopropanol , sodium sulphate) are carefully added.sodium sulphate) are carefully added.


• Both lipophilic & hydrophilic drugs Both lipophilic & hydrophilic drugs could be entrapped in N.P using this could be entrapped in N.P using this technique.technique.

Aqueous phase (protein aqueous solution )

Protein aggregates(coaservates)

Protein colloidal dispersion

Nanoparticle dispersion

desolvation

resolvation

Cross-linking


PPH H induced aggregationinduced aggregation• Rohdewold ,prepared gelatin nanosheresRohdewold ,prepared gelatin nanosheres Gelatin & tween 20 were dissolved in Gelatin & tween 20 were dissolved in

aqueous phase &the Paqueous phase &the PHH of the solution of the solution was adjusted to the optimum value.was adjusted to the optimum value.

the clear solution is heated to 40the clear solution is heated to 4000cc sequential temp. treatment resulted in sequential temp. treatment resulted in

to a colloidal dispersion of aggregated to a colloidal dispersion of aggregated gelatingelatin


the aggregates were finally cross-the aggregates were finally cross-linked using cross-linking agent linked using cross-linking agent (glutaraldehyde)(glutaraldehyde)

nanoparticles (size is 200 nm) nanoparticles (size is 200 nm)

• The optimal pH range for ideal & The optimal pH range for ideal & uniform preparation of gelatin N.P uniform preparation of gelatin N.P was 5.5 – 6.5was 5.5 – 6.5

• The PH value below 5.5 produced no The PH value below 5.5 produced no aggregation while above 6.5 an aggregation while above 6.5 an uncontrollable aggregation.uncontrollable aggregation.


Counter ion induced Counter ion induced aggregationaggregation• The aggregation of dispersed phase The aggregation of dispersed phase

(polysaccharides) can effectively be (polysaccharides) can effectively be initiated by adding some appropriate initiated by adding some appropriate counter ions.counter ions.

• The aggregation can be propagated The aggregation can be propagated by adding secondary species.by adding secondary species.

Eg: alginate N.P are prepared by Eg: alginate N.P are prepared by using counter – ion induced gelatin using counter – ion induced gelatin technique , where gelatin was technique , where gelatin was induced by cainduced by ca++++ , and continued by , and continued by addition of poly (1-lysine). addition of poly (1-lysine).


2. N.P preparation using 2. N.P preparation using polymerization based polymerization based method.method.

• Two different approaches are generally Two different approaches are generally adopted for the preparation of adopted for the preparation of nanospheres using in situ polymerization nanospheres using in situ polymerization technique.technique.

methods in which the monomer to be methods in which the monomer to be polymerized is emulsified in a non-solvent polymerized is emulsified in a non-solvent phase (emulsion polymerization)phase (emulsion polymerization)

Methods in which the monomer is Methods in which the monomer is dissolved in a solvent that is non-solvent dissolved in a solvent that is non-solvent for the resulting polymer. for the resulting polymer.


Emulsion polymerization Emulsion polymerization • Two different mechanisms were Two different mechanisms were

proposed for the emulsion proposed for the emulsion polymerization polymerization

Micellar nucleation (micellar Micellar nucleation (micellar polymerization mechanism)polymerization mechanism)

Homogenous nucleation Homogenous nucleation (homogenous polymerization (homogenous polymerization mechanism)mechanism)


Micellar nucleation:Micellar nucleation:


• The monomer is emulsified in the non-solvent The monomer is emulsified in the non-solvent phase with the help of surfactant.phase with the help of surfactant.

• The process leads to the formation of The process leads to the formation of monomer-swollen micelles & stabilized monomer-swollen micelles & stabilized monomer droplets.monomer droplets.

• Monomer swollen micelles exhibit size in the Monomer swollen micelles exhibit size in the nanometric range and having large surface nanometric range and having large surface area in comparison to monomer droplets.area in comparison to monomer droplets.

• The polymerization reaction proceeds through The polymerization reaction proceeds through nucleation & propagation stage in the process nucleation & propagation stage in the process of chemical & physical initiator which initiates of chemical & physical initiator which initiates the polymerization chain reaction.the polymerization chain reaction.

• The monomer droplet act as monomer The monomer droplet act as monomer reservoir.reservoir.


Homogenous nucleationHomogenous nucleation


• This mechanism is applies in cases where This mechanism is applies in cases where the monomer is sufficiently soluble in the the monomer is sufficiently soluble in the continuous phase.continuous phase.

• In this situation both the micelles & droplets In this situation both the micelles & droplets play the role of monomer reservoirs.play the role of monomer reservoirs.

• When the oligomers have reached a certain When the oligomers have reached a certain length ,they ppt & form primary length ,they ppt & form primary particles.which are stabilized by the particles.which are stabilized by the surfactant molecules.surfactant molecules.

• End product N.P are formed either by End product N.P are formed either by additional monomer input in to the primary additional monomer input in to the primary particle or by infusion of the primary particle or by infusion of the primary particles.particles.


Preparation of PACA N.P using Preparation of PACA N.P using emulsion polymerization emulsion polymerization process.process.


• Water insoluble monomer is Water insoluble monomer is emulsified in an external acid aqueous emulsified in an external acid aqueous phase that contains stabilizer.phase that contains stabilizer.

• Anionic polymerization takes place in Anionic polymerization takes place in micelles after diffusion of monomer micelles after diffusion of monomer molecule through the water phase.molecule through the water phase.

• At neutral PH the rate of At neutral PH the rate of polymerization is fast leading to polymerization is fast leading to formation of aggregates.formation of aggregates.

• At acidic PH i.e 2-4 the reaction rate is At acidic PH i.e 2-4 the reaction rate is slow.slow.


• The medium is stirred in order to The medium is stirred in order to maintain the size.maintain the size.

• The water soluble drugs may be The water soluble drugs may be associated with PACA N.P either associated with PACA N.P either dissolving the drug in the aqueous dissolving the drug in the aqueous polymerization medium ( or ) by polymerization medium ( or ) by incubating the blank nanospheres incubating the blank nanospheres with an aqueous solution of drug.with an aqueous solution of drug.

• In the later the drug molecules are In the later the drug molecules are physically adsorbed only on the physically adsorbed only on the surface.surface.


Interfacial polymerization Interfacial polymerization


The core phase & drug molecules to be The core phase & drug molecules to be dissolved in a volatile solvent.dissolved in a volatile solvent.

the solution then poured in to a non-the solution then poured in to a non-solvent for both polymer and core phase.solvent for both polymer and core phase.

the polymer phase is separated the the polymer phase is separated the resultant mixture turns milky. resultant mixture turns milky.

the solvent is subsequently removed the solvent is subsequently removed under vacuum under vacuum

nanocapsules (size 30-300 nm)nanocapsules (size 30-300 nm)


N.P preparation using polymer N.P preparation using polymer precipitation methodsprecipitation methods• This method is suitable for This method is suitable for

hydrophobic polymer & hydrophobic hydrophobic polymer & hydrophobic drug.drug.

• Depending on the solvent miscibility Depending on the solvent miscibility technique they are designated as technique they are designated as solvent extraction / evaporation solvent extraction / evaporation method.method.


Preparation of PLGA Preparation of PLGA nanospheresnanospheres the PLGA polymer is solubilized in a the PLGA polymer is solubilized in a

solvent (chloroform) & dispersed in a solvent (chloroform) & dispersed in a gelatin solutiongelatin solution

o/w emulsiono/w emulsion

nanospheresnanospheres

High speed / pressurehomogenization

Solvent evaporation


Double emulsion solvent Double emulsion solvent evaporation methodevaporation method


Salting outSalting out• This method is suitable for drug & This method is suitable for drug &

polymer that are soluble in polar polymer that are soluble in polar solvents (acetone or ethanol).solvents (acetone or ethanol).


Novel nanoparticulate Novel nanoparticulate systemsystemSolid lipid N.P (SLNs)Solid lipid N.P (SLNs)• Suitable for i.v administration.Suitable for i.v administration.• They are made of solid hydrophobic They are made of solid hydrophobic

core having a mono layer of core having a mono layer of phospholipids coating.phospholipids coating.

• The solid core contains the drug The solid core contains the drug dissolved or dispersed in the solid high dissolved or dispersed in the solid high melting fat matrix.melting fat matrix.

• They have potential to carry liphophilic They have potential to carry liphophilic or hydrophilic drug or diagnostics. or hydrophilic drug or diagnostics.


Advantages:Advantages:

• Low systemic toxicity.Low systemic toxicity.

• Low cytotoxicity.Low cytotoxicity.

• Large scale production is possible.Large scale production is possible.

• Not degraded by autoclaving.Not degraded by autoclaving.

• Shows sustain release.Shows sustain release.

• Relatively cheaper & stable.Relatively cheaper & stable.


Preparation of SLNsPreparation of SLNs• Hot homogenization techniqueHot homogenization technique melting of the lipidmelting of the lipid

dissolution of the drug in the melted lipid dissolution of the drug in the melted lipid

mixing of the preheated dispersion mixing of the preheated dispersion medium & the drug lipid melt medium & the drug lipid melt

premix using a stirrer to form a coarse pre-premix using a stirrer to form a coarse pre-emulsion emulsion

high pressure homogenization at a temp. high pressure homogenization at a temp. above the lipids melting pointabove the lipids melting point


o/w nano emulsion o/w nano emulsion

solidification of the nano-emulsion solidification of the nano-emulsion by cooling down to room temp. to by cooling down to room temp. to form SLN.form SLN.


Cold homogenization Cold homogenization techniquetechnique melting of the lipidmelting of the lipid

dissolution / solubilization of the drug dissolution / solubilization of the drug in the melted lipidin the melted lipid

solidification of the drug loaded lipid solidification of the drug loaded lipid in liquid nitrogen or dry icein liquid nitrogen or dry ice

grinding in a power mill (50-100 grinding in a power mill (50-100 μμm)m)


dispersion of the lipid in the cold dispersion of the lipid in the cold aqueous dispersion medium aqueous dispersion medium

solid lipid nanoparticlessolid lipid nanoparticles


Hydrogel N.P:Hydrogel N.P:• Hydrogel n.p are formed in water by Hydrogel n.p are formed in water by

self assemblage & self aggregation of self assemblage & self aggregation of natural polymer such as cholesteroyl natural polymer such as cholesteroyl dextran, cholesteroyl mannan.dextran, cholesteroyl mannan.

• Cholesterol groups provide cross-Cholesterol groups provide cross-linking points in a non-covalent linking points in a non-covalent manner.manner.

• The size & density of hydrogel n.p can The size & density of hydrogel n.p can be controlled by changing the degree be controlled by changing the degree of substitution of cholesterol groups. of substitution of cholesterol groups.


Nanosuspensions Nanosuspensions The drug powder is dispersed in an aqueous The drug powder is dispersed in an aqueous

surfactant sol. By high speed stirringsurfactant sol. By high speed stirring

The obtained macro-suspension is passed The obtained macro-suspension is passed through a high speed homogenizerthrough a high speed homogenizer

Formation of n.s of the poorly water soluble Formation of n.s of the poorly water soluble drug. drug.


• Muller & co-workers , in 2001 . Muller & co-workers , in 2001 . Discussed mucoadhisive n.p for oral Discussed mucoadhisive n.p for oral delivery & surface – modified drug delivery & surface – modified drug n.p for site – specific delivery to n.p for site – specific delivery to brain. brain.


Ph’ceutical aspects of n.p Ph’ceutical aspects of n.p • Three important process parameters Three important process parameters

are performedare performedPurificationPurificationGel filtrationGel filtrationDialysisDialysisUltra-centrifugationUltra-centrifugation


Cross – flow filtration method Cross – flow filtration method • This method can be scale-up from an This method can be scale-up from an

industrial stand pointindustrial stand point


Freeze drying Freeze drying • AdvantagesAdvantagesPrevention from degradation / Prevention from degradation /

solubilization of the polymer.solubilization of the polymer.Prevention from drug leakage , drug Prevention from drug leakage , drug

adsorptions , or drug degradation.adsorptions , or drug degradation.Easy to handle & store & help in long Easy to handle & store & help in long

term preservation.term preservation.


sterilizationsterilization• For parenteralsFor parenterals

• For other delivery systems like For other delivery systems like filtration through 0.22 filtration through 0.22 μμm membrane m membrane filter. (do not used always for n.p filter. (do not used always for n.p because microorganisms & n.p may because microorganisms & n.p may be larger in size 0.25-1.0 be larger in size 0.25-1.0 μμm)m)

• Autoclaving & Autoclaving & γγ –irradiation. –irradiation.


Characterization of n.pCharacterization of n.p• Size & morphologySize & morphologyTwo main techniques Two main techniques photon correlation photon correlation

spectroscopy(PCS)spectroscopy(PCS) electron microscopy(measures the electron microscopy(measures the

particle size & its distribution)particle size & its distribution)Gold coating is done for the n.p for Gold coating is done for the n.p for

the study of morphology.the study of morphology.


• Specific surface areaSpecific surface areaThe s.s area of n.p is determined The s.s area of n.p is determined

with the help of sorptometer.with the help of sorptometer.

A=6/A=6/∂.d∂.d

∂ ∂-density-density

d-diameter of particled-diameter of particle

• surface chargesurface charge


In vitro releaseIn vitro release• N.P can be evaluated in phosphate buffer N.P can be evaluated in phosphate buffer

utilizing double chamber diffusion cell on a utilizing double chamber diffusion cell on a shaker stand .shaker stand .

• A Millipore hydrophilic low- protein binding A Millipore hydrophilic low- protein binding membrane is placed between the two membrane is placed between the two chambers.chambers.

• The donor chamber is filled with The donor chamber is filled with nanoparticulate suspension and the nanoparticulate suspension and the receptor chamber with plane bufferreceptor chamber with plane buffer

• The receptor chamber is assayed at The receptor chamber is assayed at different time intervals for the drug using different time intervals for the drug using standard procedure. standard procedure.


Therapeutic applications of N.P Therapeutic applications of N.P applicationapplication materialmaterial purposepurpose

Cancer Cancer therapytherapy

Intracellular Intracellular targetingtargeting

Poly(alkylcyanPoly(alkylcyanoacrylate)oacrylate)

Poly(alkycyanPoly(alkycyanoacrylate)polyoacrylate)polyesters n.p esters n.p with antiviral with antiviral agent.agent.

Reduced Reduced toxicity,enhantoxicity,enhanced of ced of antitumorageantitumoragentnt

Target Target reticuloendothreticuloendothelial system elial system for for intracellular intracellular infections.infections.


Vaccine Vaccine adjuvantadjuvant

Peroral Peroral absorptionabsorption

Ocular deliveryOcular delivery

Poly(methylmePoly(methylmethacrylate) thacrylate) (oral and (oral and intramuscular intramuscular immunization)immunization)

Poly(methylmePoly(methylmethacrylate)with thacrylate)with proteins & proteins & therapeutic therapeutic agentagent

Poly(alkylcyanoPoly(alkylcyanoacrylate)n.p acrylate)n.p with with steroids,anti steroids,anti bacterial bacterial agent.agent.

Enhance Enhance immune immune response.response.

Enhanced Enhanced bioavailability, bioavailability, protection from protection from gastrointestinal gastrointestinal enzymes. enzymes.

Improved Improved retention of retention of drug.drug.


Other Other applicationsapplications

Poly(alkylcyanoPoly(alkylcyanoacrylate)n.p acrylate)n.p with peptides.with peptides.

Poly(alkylcyanoPoly(alkylcyanoacrylate)n.p for acrylate)n.p for transdermal transdermal application.application.

N.P with N.P with adsorbed adsorbed enzymes.enzymes.

Crosses blood Crosses blood brain barrierbrain barrier

Improved Improved absorption & absorption & permeation.permeation.

Enzyme Enzyme immunoassays.immunoassays.


References……References……• S.P.vyas and R.K.khar ,controlled S.P.vyas and R.K.khar ,controlled

drug delivery-concept and drug delivery-concept and advances ,Vallabh prakashan,new advances ,Vallabh prakashan,new Delhi ,first eddition 2002Delhi ,first eddition 2002

• N.K. jain ,controlled and novel drug N.K. jain ,controlled and novel drug delivery ,CBS publishers delivery ,CBS publishers &distributors,new delhi.&distributors,new delhi.

• Indian drugs.Indian drugs.

• www.google.comwww.google.com

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