Nanoparticles

Definition, Types, Preparation, Evaluation, Applications

1. NANOPARTICLES BINU ANAND 1 ST YEAR M.PHARM NAZARETH COLLEGE OF PHARMACY 1

2. DEFINITION: “ N anoparticles are sub- nanosized colloidal structures composed of synthetic or semi-synthetic polymers.” Size range : 10–1000 nm The drug is dissolved, entrapped , encapsulated or attached to a nanoparticle matrix . Based On Method Of Preparation: Nanocapsules :- Nanocapsules are systems in which the drug is confined to a cavity surrounded by a unique polymer membrane . Nanospheres :- Nanospheres are matrix systems in which the drug is physically and uniformly dispersed. 2

3. Classification of Nanoparticles: Solid Lipid Nanoparticles Polymeric Nanoparticles Ceramic Nanoparticles Hydrogel Nanoparticles Copolymerized Peptide Nanoparticles Nanocrystals and Nanosuspensions Nanotubes And Nanowires Functionalized Nanocarriers 3

4. Advantages of Nanoparticles: Nano particle can be administered by parenteral, oral, nasal,occular routes . By attaching specific ligands on to their surfaces, nanoparticles can be used for directing the drugs to specific target cells . Improves stability and therapeutics index and reduce toxic effects. Both active & passive drug targeting can be achieved by manipulating the particle size and surface characteristics of nanoparticles. 4

5. Disadvantages Of Nanoparticles Small size & large surface area can lead to particle aggregation . Physical handling of nano particles is difficult in liquid and dry forms . Limited drug loading . Toxic metabolites may form. 5

6. Preparation of polymeric Nanoparticles Dispersion polymerization (DP ) Emulsion polymerization (EP ) Solvent evaporation method Solvent Displacement method EP in aqueous contineous phase EP in organic continuous phase Salting out tech. Polymerization methods Polymer precipitation method Cross-linking 6 Heat cross-linking Chemical cross-linking

7. Nanoparticle Prepared By Polymerization Method Dispersion polymerization (DP): Used for preparation of biodegradable polyacrylamide & polymethyl methacrylate (PMMA). The acrylate or methyl methacrylate monomer is dissolved in aqueous phase. polymerization by γ -irradiation or chemical initiation combined with heating to tem. above 65 ˚c. The oligomer formed subsequently aggregate & above certain molecular weight precipitate in the form of nanoparticles 7

8. 2. Emulsion polymerization (EP): Monomer Dissolved in aqueous phase which contains an initiator which is a surfactant Vigorous agitation Emulsion formation Particle smaller than 100nm Initiator which generates either radicals or ions depending upon the type of initiator & these radicals or ions nucleate the monomeric unit & starts polymerization process . 8

9. B. Polymer precipitation method:- 1 . Solvent evaporation method : Drug & polymer is dissolved in organic solvent. Emulsified with an aq. phase containing surfactant to obtain o/w emulsion. Organic phase is then evaporated Nanoparticles Example : polylactic acid nanoparticle loaded with testosterone using poloxamer 188 as stabilizer by using homogenizer. 9

10. 2. Solvent displacement / Nanoprecipitation : Useful for slightly water soluble drug. Drug dissolved in organic phase(ethanol/methanol) Aq.phase Displacement of organic phase Immediate polymer precipitation because of complete miscibility of both the phase . Nanoparticles Emulsified 10

11. 3. Salting out method : Suitable for drug & polymers that are soluble in polar solvent such as acetone or ethanol. 11

12. C) Cross-linking 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 12

13. Characterization of Nanoparticles 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 13

14. 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 14

15. 8) Invitro Release : > Diffusion Cell . > Recently Introduced Modified Ultra Filtration Technique. > Media Used : Phosphate Buffer 9) Nanoparticle Yield : % yield = Actual weight of Product X 100 Total weight of Drug and Excipients 10) Drug entrapment efficency : % entrapment = mass of drug in nanoparticles X 100 mass of drug used in formulation 15

16. Applications 1) Widely used in case of Cancer Therapy. 2) In lntracellular Targeting 3) 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 immunoassays 9) Radio-imaging. 10) To cross BBB . 16

17. EMEND Rapamune OLAY MOISTURIZERS (Merck & Co. Inc ) (Wyeth-Ayerst Laboratories) (American Biosciences, Inc.) ABRAXANE (Proctor and Gamble) MARKETED FORMULATIONS 17

18. Conclusion Nanoparticles are one of the novel drug delivery systems, which can be of potential use in controlling and targeting drug delivery as well as in cosmetics textiles and paints. Judging by the current interest and previous successes, nanoparticulate drug delivery systems seems to be a viable and promising strategy for the biopharmaceutical industry . 18

19. References Encyclopedia of controlled drug delivery system, edited by Edith Mathiowitz , 551-564 . Vyas S.P. , Khar R.K. Targeted & Controlled Drug Delivery, Novel Carrier Systems, CBS Publication ,2002 , 249-277,331-387. www.pharmainfo.net/reviews/nanoparticles-and-its-applications-field-pharmacy Jain N. K., Controlled and novel Drug Delivery, 1st edition 2001, CBS Publication; 292 - 301. 19

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