Pharmaceutical Nanoparticles

Types, Preparation and Evaluation of Nanoparticles

1. Nanoparticles SILAMBARASAN I M PHARM DEPT OF PHARMACEUTICS MTPG & RIHS 1

2. CONTENTS INTRODUCTION HISTORY DEFINITION NEED OF NANOPARTICLES ADVANTAGES DISADVANTAGES IDEAL CHARACTERSTICS POLYMERS USED PREPARATION OTHER TYPE OF NANOPARTICLES EVALUATION APPLICATION CONCLUSION REFERENCES 2

3. Introduction- nanotechnolgy The word ‘Nano’ is derived from Latin word, which means “dwarf” (1nm=10 -9m ). Nanotechnology is science of the small , the very small used to prepare matter at tiny scale. “FUTURE OF TECHNOLOGY” 3

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5. history The Nobel prize in physics (1965) winner “RICHARD FEYMAN” is known as “FATHER OF NANOTECHNOLGY” published the paper of “THERE’S PLENTY OF ROOM AT BOTTOM” . Over a decade later, Professor “NORIO TANIGUCHI” actually coined the term nanotechnology. Nanoparticles as a drug delivery vehicle were first developed by “ Spieser and co-workers” in the early 1980s.(NANOPELLETS AND MICROPELLETS) 5

6. Nanoparticles -DEFINITION Nanoparticles are sub- nanosized colloidal drug delivery system . Its size ranges from 1-100nm in diameter. They are composed of synthetic or semi synthetic polymers carrying drugs or proteinaceous substances, i.e. antigen(s). The first reported nanoparticles were based on non-biodegradable polymeric systems. Eg: Polyacrylamide 6

7. Need of nanoparticles Nanoparticles are of interest because of new properties that they exhibit compared with larger particles of the same materials. Eg: TiO 2 , ZnO become transparent at nanoscale The major goal of designing nanoparticles as a delivery system are to control particle size and release of pharmacologically active agents in specific site at controlled rate. 7

8. Advantages Site specific targeting Reduced Toxicity Reduction in the frequency of the dosages Drug loading is high Easy penetration through capillaries Eg , IN CANCER CHEMOTHERAPY, CYTOSTATIC DRUGS DAMAGE BOTH MALIGNANT AND NORMAL CELLS . BUT NANODRUG DELIVERY SELECTIVELY TARGETS MALIGNANT TUMOR CELLS ONLY….. 8

9. ROUTES : 9

10. DISADVANTAGES High manufacturing cost Large volume of solvent is utilized Physical handling of particles is difficult Difficult to maintain stability of dosage form Reduced ability to adjust the dose Requires skills to manufacture 10

11. IDEAL CHARACTERSTICS Biochemically inert, non toxic ,non- immunogenic. Restrict drug distribution to non target cells or tissues or organs & should have uniform distribution. Controllable and predictable rate of drug release. Carrier used must be biodegradable or readily eliminated from the body without any problem. It should be stable both physically and chemically in in-vivo and in-vitro condition. 11

12. Polymers used in preparation of nanoparticles 12

13. Natural hydrophilic polymer DISADVANTAGES: Batch to batch variation Conditional biodegradability antigenicity 13

14. Synthetic hydrophobic polymer 14

15. PREPARATION TECHNIQUES OF NANOPARTICLES The selection of the appropriate method for the preparation of nanoparticles depends on , 1)Physicochemical characteristics of the polymer 2)Drug to be loaded Drug may be added during preparation of nanoparticles or to the previously prepared nanoparticles. 15

16. Approaches Applied The “ top-down ” approach, which involves the breaking down of large pieces of material to generate the required  nanostructures  from them. The “ bottom-up ” approach, which implies assembling single  atoms and  molecules  into larger nanostructures . Bottom-up Top-down nanoparticles 16

17. Types of nanoparticles Nanoparticles Nanocapsules Nanospheres Have core shell structure(RESERVOIR) Represent matrix system 17

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19. Methods of preparation 1 ) Amphiphilic Macromolecule Cross Linking Methods Heat cross linking Chemical cross linking 2) Polymer Precipitation Methods Emulsion Solvent evaporation method Double emulsion solvent evaporation method Solvent displacement(nanoprecipitation) Salting out 3) Polymerization Methods Emulsion polymerization Dispersion polymerization Interfacial polymer condensation 19

20. 1) Amphiphilic macromolecule cross-linking Nanoparticles can be prepared from amphiphilic macromolecules, proteins and polysaccharides (which have affinity for aqueous and lipid solvents) . Technique of their preparation involves: Aggregation of amphiphiles (by HEAT OR CHEMICAL CROSSLINKING) Stabilization 20

21. Aqueous protein (BSA ) Oil Emulsification using high-pressure homogenization or high frequency sonication Surfactant W/O emulsion Poured in preheated oil above 100 o C or chemical cross linking agent Stirred to form aggregates Wash with organic solvent Centrifugation and isolation of nanoparticles 21

22. 2) Polymer Precipitation Methods In these methods, the hydrophobic drug or a hydrophobic polymer is dissolved in a particular organic solvent followed by its dispersion in a continuous aqueous phase, in which the polymer insoluble. The external phase also contains the stabilizer. They are 4 types Emulsion Solvent evaporation method Double emulsion Solvent evaporation method Solvent displacement method Salting out method 22

23. A) Emulsion-Solvent Evaporation Method Organic Solvents: Dichloromethane, Chloroform, Ethyl acetate. Evaporation is done by reducing the pressure or by continuous stirring. Stabilizers - polysorbates, poloxamers, sodium dodecyl sulphate. Polymer :PLA,PLGA,PCL Homogenizer speed, nature and stabilizer concentration along with the property of polymer effect size of nanoparticle. Suitable for lipid soluble drugs. 23

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25. B)Double emulsion solvent evaporations method Suitable for Hydrophilic drugs Nanoparticles are separated by centrifugation at high speed 25

26. c) Solvent Displacement /precipitation Method Drug,polymer,surfactant dissolved in organic phase(ethanol/acetone) Aq.phase with stabilizer Immediate polymer precipitation because of complete miscibility of both the phase. Nanoparticles Injected Diffusion of organic phase during stirring 26

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28. d) Salting out of Polymer Aqueous phase :Distilled water Organic Phase : Acetone Stabilizer : Poly vinyl Alcohol Salting out agent : Magnesium chloride, Calcium chloride Suitable for drug & polymers that are soluble in polar solvent such as acetone or ethanol, heat sensitive drugs . 28

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30. 3) polymerization methods Monomers are polymerized to form nanoparticles in an aqueous solution in which drug may be dissolved. Drug may also be incorporated by absorption onto the nanoparticles after polymerization completed. Eg : Polybutylcyanoacrylate nanoparticles METHODS: a) Emulsion polymerization b) Dispersion polymerization 30

31. A) Emulsion Polymerization Emulsion polymerization: - this method involves emulsification of monomer in non-solvent phase . It may be conventional or reverse, depending upon nature of continuous phase, Conventional method = Continuous phase is aqueous(O/W emulsion) Reverse method = Continuous phase is organic (W/O emulsion) 31

32. CONT, Dissolve lipophilic monomer in water then add surfactant with hydrophilic heads and lipophilic tails Formed micelles in water Lipophilic monomer escape from water and enter the lipophilic core of micelles Add “RADICAL INITIATOR” ,which enter micelles and force monomer to form a polymer via polymerisation process Then the micelles dissociate and the polymer chains are attached to each other 32

33. Cautions : Experiment is done under nitrogen atmosphere as oxygen interferes with it. 33

34. B)Dispersion polymerization - Monomer is dissolved in the Aq medium, which acts as a precipitant for formed polymer. -Nucleation is directly induced in Aq. Monomer solution. -So STABILIZER/ SURFACTANT is no needed Here initiation is achieved by different mechanism, but mostly it is by irradiating solution with high energy radiation (Gamma, UV, strong visible light). 34

35. Other TYPES OF NANOPARTICLES : SOLID LIPID NANOPARTICLE NANOCRYSTALS NANOSUSPENSION NANOEMUSIONS LIPOSOMES DENDRIMERS NANOSHELLS COATED WITH GOLD CARBON NANOTUBES QUANTUM DOTS NANOGELS 35

36. 1) Solid Lipid Nanoparticles (SLNs) These are a new generation of submicron-sized lipid emulsions where the liquid lipid (oil) has been substituted by a solid lipid. SLNs offer unique properties such as small size, large surface area, high drug loading & the interaction of phases at the interfaces , & are attractive for their potential to improve performance of Pharmaceuticals, Nutraceuticals & other materials. Phospholipids monolayer 36

37. Advantages 1) Control & target drug release 2) Good biocompatibility 3) Feasibility of carrying both lipophilic & hydrophilic drugs 4) High & enhanced drug content when compared to other carriers 5) Improves the stability of pharmaceuticals 6) Low toxicity 37

38. Preparation of Solid-Lipid Nanoparticles SLNs are made up of solid lipid, emulsifier & water/solvent . The lipids used may be triglycerides, partial glycerides, fatty acids, steroids & waxes . Various emulsifiers & their combinations like pluronic F68 , F 127 can be used to stabilize the lipid dispersion. 38

39. Different methods of preparation of SLNs A) High pressure homogenization - Hot homogenization - Cold homogenization B) Ultra sonication/high speed homogenization C) Solvent emulsification/evaporation D) Double emulsion method E) Micro emulsion based SLNs preparations F) SLNs preparation by using supercritical fluid G) Spray drying method 39

40. A) High pressure Homogenization This technique was initially used for the production of solid-lipid Nano dispersions . Lipids used in this study are tripalmitin , mixture of mono, di glycerides (witepsolW35). Glycerol behenate & poloxamer 188 as steric stabilizers (0.5% w/w). By using Witepsol W35 dispersions the best SLNs quality was obtained after stirring for 8min at 20,000 rpm followed by cooling for 10min & stirring at 5000 rpm at a room temperature. 40

41. Hot Homogenization Lipid melted Dissolution of the drug in melted lipid Premix using a stirrer to form a coarse pre-emulsion High-pressure homogenization at a temperature above the lipid melting point Mixing O/W Nano emulsion SLN Solidification of nano -emulsion by cooling at room temp. 41

42. Cold Homogenization Lipid melted Solubilization of drug in melted lipid Solidification of the drug loaded lipid in liquid nitrogen or dry ice. Grinding in a power mill SLN Lipid dispersed in cold aqueous dispersion medium 42

43. B) Ultra sonication or High Speed Homogenization In this method the SLNs are produced by high speed stirring or sonication . Advantage : 1) Equipment used is very common 2) No temperature induced drug degradation Disadvantage : Physical instability like particle growth upon storage . 43

44. C) Solvent Emulsification/Evaporation Method In this method, lipophilic material is dissolved in water immiscible organic solvent (e.g., cyclohexane ) that is emulsified in an aqueous phase to give oil/water (o/w) emulsion . On evaporation of the solvent under reduced pressure , solid lipid nanoparticles dispersion is formed. Adv :- Avoidance of any thermal stress. Disadv :- use of organic solvents. 44

45. D) Double Emulsion Method This method is modification of emulsion solvent evaporation. Organic solvent, drug and distilled water form the W/O emulsion by sonication or homogenization and stabilized at 4 o C . Adding the aqueous phase with stabilizer to form double emulsion W/O/W. Evaporation of solvent to form SLNs. Washed and lyophilised. It is used for the preparation of hydrophilic loaded SLNs . 45

46. E) Micro emulsion based SLNs preparation A warm micro emulsion is prepared by stirring, containing typically 10% molten solid lipid , 15% surfactant & upto 10% co-surfactant . This warm micro emulsion is then dispersed under stirring in excess cold water (typical ratio 1:50 ) using thermostated syringe. The excess water is removed either by ultrafiltration or by lyophilisation in order to increase the particle concentration. 46

47. F) by using Supercritical Fluid This is a new technique for SLNs production. SLNs can be prepared by the rapid expansion of supercritical carbon dioxide solutions (Rapid Expansion of Supercritical Solution) method. Carbon dioxide (99.99%) is a good choice as a solvent for this method. 47

48. G) Spray Drying Method The lipid is first dissolved in suitable volatile organic solvent. The drug in solid form is then dispersed in the solution under high speed homogenization. This dispersion is then atomized in a stream of hot air. The atomization leads to formation of droplets from which solvent evaporate instantly to form SLN. Disadvantages: This method causes particle aggregation due to high temperature shear forces & partial melting of the particle. Recommended use of lipid with M.P >70 c for spray drying. 48

49. 2) Drug NANOCRYSTALS Drug Nanocrystals are crystals with a size in the nanometre range , which means they are nanoparticles with a crystalline character . A further characteristic is that drug nanocrystals are composed of 100% drug ; there is no carrier material as in polymeric nanoparticles. Nanocrystals also possess advantages of increased bioavailability & increase in saturation solubility . 49

50. Preparation of Nanocrystals Mainly 3 methods, a. Milling b. Precipitation c. Homogenization methods as well as a combination of the above 50

51. a. Milling Method Small milling pearls or large milling balls are used as milling media. With a reduction in the size of grinding media in a media mill, the number of contact points is increased results in improved grinding leads to smaller particles. The balls consist of ceramic, stainless steel or highly cross linked polystyrene resin coated beads. 51

52. b. Precipitation Method A poor water-soluble drug is dissolved in an organic solvent, which is water miscible. Pouring of solution into a non-solvent, such as water, leading to the precipitation of finely dispersed drug nanocrystals. A problem associated with this technology is that the formed nanoparticles need to be stabilized to avoid growth in micrometer crystals . 52

53. c. Homogenization Method Three technologies are used for preparation of nanocrystals by homogenization methods which are Micro fluidizer technology, Piston gap homogenization in water, Piston gap homogenization in water mixtures or non aqueous media. 53

54. 3) Nano suspensions Pharmaceutical Nano suspension is defined as very finely dispersed solid drug particles in an aqueous vehicle . The particle size in Nano suspension ranges between 200 - 600nm . Stabilized by surfactant . Dispersion of drug nanocrystals in liquid media leads to “ nanosuspensions ” . Dispersion media can be water , aqueous solutions or non aqueous media (e.g., liquid polyethylene glycol ( PEG ), oils ). 54

55. Advantages of Nano suspensions 1) Applied for the poorly water soluble drugs. 2) Improved biological performance 3) Ease of manufacture & scale-up 4) Long-term physical stability 5) Rapid bioavailability in the oral administration 55

56. Preparation of Nano suspensions Two techniques are used for the preparation of Nano suspensions which are a. Bottom-up technique by; I. Micro precipitation, II. Micro emulsion b. Top- down technique by; I. High pressure homogenization, II. Wet milling method 56

57. 4) Nano Emulsions Nano emulsions may be defined as oil-in-water (o/w), water- in-oil (w/o) emulsions with mean droplet diameters ranging from 50 to 1000nm . Usually, the average droplet size is between 100 & 500 nm. The particles can exist as water-in-oil & oil-in-water forms, where the core of particle is either water or oil, respectively. 57

58. Advantages Do not show the problems of inherent creaming, flocculation, coalescence, & sedimentation, which are commonly associated with macro emulsions. These can be formulated in variety of formulations such as foams, creams, liquids, & sprays. These are non-toxic & non-irritant, hence can be easily applied to skin & mucous membranes . Reduction of globules as the potential to -Increase surface area -Enhance solubility -Increase oral bioavailability - 58

59. Nano emulsions are prepared by three methods: a. High-pressure homogenization b. Micro fluidization c. Phase inversion method. NANOEMULSION-METHODS 59

60. 5) LIPOSOMES Liposomes are simple microscopic vesicles in which an aqueous volume is entirely enclosed by a Phospholipids bilayer molecule. The size of a liposome ranges from some 20 nm up to several micrometres. 60

61. Classification Based on size & no. of bilayer: Small unilamellar vesicles [ SUV ] Large unilamellar vesicles [ LUV ] Multilamellar vesicles [ MLV ] . 61

62. 6) Dendrimers The name comes from Greek Word “Dendron” which means “TREE”. They are family of Nano sized ,highly branched three dimensional molecules. The first & most widely studied dendrimers are polyamidoamine ( (PAMAM) dendrimer. 62

63. cONT, They consist of three major architectural components:  1. Core 2. Branching Unit   3. End groups 63

64. 7) NANOSHELLS COATED WITH GOLD This is type of spherical nanoparticle consisting of dielectric core which is covered by a thin metallic shell . In cancer applications, antibodies or other biomolecules are attached to the gold surface to target at tumor site. -Dielectric core ( gold sulfide or silica) -Metal shell (gold) 64

65. Particle < 75 nm diameter absorb & others scatter the incidence light. Nano shells strongly absorb infrared light while normal tissue is transparent to it. Nano shell-antibody complex binds only to cancer cells. Infrared laser heats up the Nano shells and thus cancer cells are destroyed. Use : Destroy breast cancer cells cont , 65

66. 8) Carbon nanotubes Carbon nanotubes are hexagonal networks of carbon atoms. 1nm in diameter & 1-100nm in length . Two types of nanotubes are present 1) single-walled nanotubes 2) multi-walled nanotubes 66

67. Cont , The advantages of nanotubes are ultra-light weight, high mechanical strength, & high surface area . Due to their size & shape, carbon nanotubes can enter living cells without causing cell death or obvious damage . Carbon nanotubes have the ability to transport drug molecules, protein & nucleotides. 67

68. 9) Quantum dots Quantum dots (QDs) are semiconducting nanomaterials consisting of a semiconductor core ( Cadmium selenide ), coated by a shell (e.g., ZnS ). These are used as diagnostic tools, detection & analysis of biomolecules, immunoassays, DNA hybridization, & transport vehicles for DNA, protein, drugs or cells. 68

69. Gene delivery Drug delivery Bio sensing Stem cell tracking Cancer studies Biopsy application 69

70. 10) Nanogels Nano gels are cross-linked nanoscale particles made of flexible hydrophilic polymers. These are soluble in water . Nano gels possess large surface area. These are used to incorporate drugs, DNA/RNA & inorganic molecules . These are also used for pH dependent release . 70

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72. characterization &Evaluation of nanoparticles : 1. Particle size : Photon correlation spectroscopy(PCS) : For smaller particle. Laser diffractrometry : For larger particle . Electron microscopy (EM) Transmission electron microscopy (TEM) : Easier method & Permits differentiation among Nano capsule & nanoparticle . Atomic force microscope Laser force microscope Scanning electron microscope Dynamic light scattering (For Nano suspension) 72

73. 2.Density : Helium or air using a gas pycnometer Density gradient centrifugation 3. Molecular weight : Gel permeation chromatography using refractive index detector. 4. Structure & Crystallinity : X-ray diffraction Thermoanalytical method such as, 1) Differential scanning calorimetry 2) Differential thermal analysis 3) Thermogravimetry 73 Cont ,

74. Cont , 5. Surface charge: Surface charge of particle can be determined by measuring particle velocity in electrical field. -Laser Doppler velocimetry -Zeta potentiometer 74

75. 6. Nanoparticle yield : 7. Drug entrapment efficiency : 75 Cont ,

76. Invitro release 76 USP TYPE 2 (PADDLE) RPM 50 IMMERSED IN 900 ML OF PHOSPHATE BUFFER SOLUTION TEMPERATURE 37±0.02 O C WITHDRAWN 5 ML SOLUTION FROM THE MEDIUM SPECIFIC TIME PERIODS SAME VOLUME OF DISSOLUTION MEDIUM IS REPLCED IN THE FLASK MAINTAIN THE CONSTANT VOLUME WITHDRAWN SAMPLE ANALYSED USING UV SPECTROPHOTOMETER

77. Stability of nanoparticles 77 NANOPARTICLES DETERMINATION STORING OPTIMIZED FORMULATION SAMPLE ANALYSED STABILTY CHAMBER FOR 90 DAYS SAMPLE ANALYSED STABILTY CHAMBER FOR 90 DAYS 4 O C±2 O C 30 O C±2 O C 0,1,2 and 3 month time period

78. Applications 78

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80. CONCLUSION The main goal of this presentation is to describe the nanoparticles, method of preparations,types and characterization of nanoparticles . The drug loaded nanospheres or Nano capsules now can be produced by simple, safe and reproducible techniques available. The limitation is one particular process is not suitable for all drugs. Despite these technological challenges ,nanoparticles have been showing great promise for the development . 80

81. REFERENCEs TARGETED AND CONTROLLED DRUG DELIVERY by S.P. VYAS and R.K. KHAR www.slideshare.net www.authorstream.net https://ebrary.net/61141/engineering/solid_lipid_nanoparticle_production_techniques https://www.slideshare.net/PriyankaChakote1/drug-nanocrystals https://www.slideshare.net/patilom/seminar-on-nanosuspension https://www.slideshare.net/sagarsavale1/nanoemulsion-61446929 https://www.slideshare.net/rozaboalkhair/roznano 81

82. THANK YOU……………… 82