NANOPARTICLES

Presented By Bindiya Patel

M.PHARM (PHARMACEUTICS)

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CONTENTS1. INTRODUCTION2. CONCEPT3. ADV AND DISADV4. IDEAL CHARACTERISTICS5. METHOD OF PREPARATION6. CHARACTERIZATION7. EVALUATION8. APPLICATIONS

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INTRODUCTION

» DEFINITION:

» Nanoparticles are subnanosized colloidal drug delivery systems

» particle size ranges from 10-1000 nm in diameter.

» They are composed of synthetic or semi synthetic polymers carrying drugs or proteinaceous substances, i.e. antigen(s).

» Drugs are entrapped in the polymer matrix particulates or solid solutions or may be bound to particle surface by physical adsorption or in chemical form.

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CONCEPT» The basic Concept involved is :

» Selective and Effective Localization of pharmacologically active moiety at preselected target(s) in therapeutic concentration,,

» Provided restriction of it’s access to non-target normal tissues and cells.

» Nanoparticles are mainly taken by : Reticulo Endothelial System (RES), After the administration;

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» Hence are useful to carry drugs to the liver and to cells that are phagocytically active.

» By modifying the surface characteristics of the nanoparticles it is possible to enhance the delivery of drugs to spleen relative to the liver.

» Distribution of the nanoparticles in the body may be achieved possibly by :

» Coating of nanoparticles with certain Serum components, Attachment of antibodies or sulfoxide groups and the use of Magnetic nanoparticles.

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ADVANTAGES » Reduction in the frequency of the dosages

taken by the patient» More uniform effect of the drug» Reduction of drug Side Effects» Reduced fluctuation in circulating drug levels» Avoids hepatic first pass metabolism

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DISADVANTAGES

» High cost» Productivity more difficult» Reduced ability to adjust the dose» Highly sophisticated technology» Requires skills to manufacture» Difficult to maintain stability of dosage form. E.g.: Resealed erythrocytes stored at 40C.

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IDEAL CHARACTERISTICS» It should be biochemical inert , non toxic and

non-immunogenic.

» It should be stable both physically and chemically in Invivo & invitro conditions.

» Restrict drug distribution to non-target cells or tissues or organs & should have uniform distribution.

» Controllable & Predicate rate of drug release.

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» Drug release should not effect drug action

» Specific Therapeutic amount of drug release must be possessed

» Carriers used must be biodegradable or readily eliminated from the body without any problem and no carrier induced modulation in disease state.

» The preparation of the delivery system should be easy or reasonable

» simple, reproducible & cost effective.

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Method of preparation

A : Cross Linking Methods » 1) By Cross-linking of Amphiphilic Macromolecules» 2) By Crosslinking in W/O Emulsion» 3) By Emulsion chemical dehydration» 4) By Phase Separation » 5) By pH lnduced Aggregation

B : Polymerization Methods

» 1) Emulsion polymerization» 2) Dispersion polymerization

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1) By Cross-linking of Amphiphilic Macromolecules» Nanoparticles can be prepared from Amphiphilic macromolecules,

proteins and polysaccharides (which have affinity for aqueous and lipid solvents).

» The method involves Aggregation of Amphiphiles followed by stabilization either by heat denaturation or chemical cross-linking

2) By Cross linking in W/O Emulsion

» Emulsification of bovine serum albumin (BSA) OR human serum albumin (HSA) or protein aqueous solution in oil using high-pressure homogenization or high frequency sonication.

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Aqueous protein (BSA)

Oil

W/O emulsion

Dilution with preheated oil (100oC)(Heat cross-linking) Or Addition of crosslinking agent(Chemical cross-linking)

Centrifugation and isolation of nanoparticles

Emulsification using high-pressure homogenization or high frequency sonication

Surfactant

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3) Emulsion Chemical Dehydration

» Stabilization can also be achieved by emulsion chemical dehydration.

» Hydroxy propyl cellulose solution in chloroform is used as a continuous phase,

» while a chemical dehydrating agent, » 2,2, di-methyl propane is used to disperse into the

internal aqueous phase to form an Emulsion.

» ADV: The method avoid coalescence of droplets and could produce nanoparticles of smaller size (300nm),

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4) Phase seperation

» The protein or polysaccharide from an aqueous phase can be Desolvated by :˃ A) pH change ˃ B) Change in temperature ˃ C) Addition of appropriate counter ions e.g. alginate

Aqueous phase(protein aqueous solution)

Protein aggregates (Coacervates)

Protein colloidal dispersion

Nanoparticles dispersion (External aqueous phase) 200nm

Desolvation

Resolvation

Cross-linking

Heat to 40o C , subsequent cooling to 4O C for 24h.

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5) pH lnduced Aggregation

» Gelatin Nanospheres were prepared by : Gelatin & tween 20 were dissolved in aq. phase & pH

of the solution was adjusted to optimum value. The clear solution so obtained was heated to 400C

followed by its quenching at 40C for 24hrs & subsequently left at ambient temperature for 48hrs.

The sequential temperature treatment resulted into a colloidal dispersion of aggregated gelatin. The aggregates were finally cross linked using glutaraldehyde as cross linking agent the optimum pH was 5.5- 6.5.values

below 5.5 produced no aggregation while above 6.5 an uncontrolled aggregation led to the formation of larger nanospheres

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Polymerization based methods

1) Emulsion polymerization :

» IT CONSISTS OF :

» A] Micellar nucleation and polymerization :

Monomer is insoluble in continuous phase.(O/W phase)

Aqueous phase

» B] Homogenous nucleation and polymerization :

Monomer is soluble in continuous phase.(W/O phase)

Organic phase.

18Monomer bearing Nucleated micelle Stabilized polymeric micelle nanospheres

Catalyst

Monomer dropletCatalystDrug Monomer

monomer supply

(micelle) (nanospheres)

Micellar nucleation and polymerization

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Homogenous nucleation and polymerization

2] Dispersion polymerization

lsolation of nanospheres

Oligomers aggregate & precipitates

Further, By chemical initiation

(ammonium or potassium per oxo disulphate)

(Acrylamide or Methyl methacrylate) Monomer is dissolved

in an aqueous medium

Heated to above 65 C

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Solvent Evaporation Method

Solvent Displacement Method

23Salting out of Polymer

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Characterization and evaluation of nanopatricles

PARAMETER METHOD

1) Particle size - Photon correlation spectroscopy

- Laser defractometry - Scanning electron

microscopy

2) Molecular weight - Gel Chromatography

3) Charge determination - Laser Doppler Anemometry

- Zeta potentiometer

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4) Density - Helium compression pynometry

5) Crystallinity - X-ray diffraction & Differential scanning Calorimetry, Thermogravimetry

6) Hydrophobicity - Hydrophobic interaction, Chromatography

7) Surface element analysis - X-ray, photon electron

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8) Specific Surface Area :

specific surface area A = 6/Density x diameter of particle

9) Invitro Release : > Diffusion Cell . > Recently Introduced Modified Ultra Filtration Technique. > Media Used : Phosphate Buffer

10) Nanoparticle Yield : % yield = Actual weight of Product X 100

Total weight of Drug and Excipients

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Applications

1) Widely used in case of Cancer Therapy.2) In lntracellular Targeting3) Used for Prolonged Systemic Circulation.4) As a Vaccine Adjuvant.5) In Case of Ocular delivery.6) Used in DNA Delivery.7) It is used in case of Oligonucleotide delivery.8) Enzyme immunoassays9) Radio-imaging.10) To cross BBB.

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» ApplicationsApplication Purpose Material

Cancer therapy Targeting, Reduced toxicity, enhance uptake of anti-tumor agent

Polyalkylcyanoacrylate with anticancer agent

Intra cellular targeting Target reticuloendothelial system for intracellular infection

Poly alkyl cyanoarylate

Vaccine adjuvant Prolong systemic drug effect. Enhance immune response

Poly methyl metha acrylate nanoparticles with vaccines

DNA delivery Enhanced bioavailability and significantly higher expression level

DNA gelatin nanoparticles, DNA chitosan nanoparticles

Ocular delivery Improved retention of the drug and reduced washed out.

Poly alkyl cyanoacrylate nanoparticles , anti-inflammatory agent

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REFERENCE

» Targetted and controlled drug delivery by S.P. VYAS and R.K. KHAR

» Jain N.K. “Advances in controlled and novel Drug Delivery”, CBS publisher & Distributers, Edition 1st 2001, Pg. 408

» Nanotechnology in drug delivery - A Review, Indian Drugs, Issue 11,november 2011.

» http://en.wikipedia.org/wiki/Nanoparticle» http://www.pharmainfo.net/reviews/nanoparticles-review

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