Niosome

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Niosome

  1. 1. By Dr. Shreeraj Shah Associate Professor,Dept. of Pharmaceutical Technology, L.J. Institute of Pharmacy, Ahmedabad 1
  2. 2. ContentIntroductionGeneral characteristics of NiosomesAdvantage of NiosomesDisadvantage of NiosomesStructure of NiosomesContrast and similarity between Niosomes and LiposomesMethods of PreparationFactors affecting the physicochemical properties of NiosomesTypes of NiosomesCharacterization of NiosomesTherapeutic ApplicationsMarketed productsFuture ProspectsConclusion 2References
  3. 3. Introduction• Development of new drug, improving safety and efficacy of existing drugs is difficult, expensive and time consuming• At present, no available drug delivery system behaves ideally achieving all the lofty goals• Encapsulation of the drug in vesicular structures is one of the promising system• such as liposomes, niosomes, transferosomes, ethosomes and pharmacosomes etc• It delivers drug directly to the site of action, leading to reduction of drug toxicity with no adverse effects 3
  4. 4. •Vesicular drug delivery reduces the cost of therapy byimproving bioavailability of medication and also solves theproblems of drug insolubility, instability and rapid degradation•Niosomes are a novel drug delivery system, in which themedication is encapsulated in a vesicle, composed of a bilayerof non-ionic surface active agents and hence the nameniosomes•The niosomes are very small, and microscopic in size. Theirsize lies in the nanometric scale 4
  5. 5. Definition• Niosomes are synthetic microscopic vesicles consisting of an aqueous core enclosed in a bi layer consisting of cholesterol and one or more nonionic surfactants• Vesicles are prepared from self assembly of hydrated non ionic surfactants molecules 5
  6. 6. General Characteristics of Niosome•Biocompatible, biodegradable, non-toxic, non immunogenic andnon-carcinogenic•The ability of nonionic surfactant to form bilayer vesicles isdependant on the HLB value of the surfactant, the chemical structureof the components and the critical packing parameter•Niosomes can be characterized by their size distribution studies• High resistance to hydrolytic degradation•The properties of niosome depends both on composition of thebilayer & on method of their production 6
  7. 7. Advantages of Niosomes Targeted drug delivery can be achieved using niosomes the drug is delivered directly to the body part where the therapeutic effect is required Reduced dose is required to achieve the desired effect Subsequent decrease in the side effects The therapeutic efficacy of the drugs is improved by reducing the clearance rate, targeting to the specific site and by protecting the encapsulated drug Niosomes are amphiphillic i.e. both hydrophilic and lipophillic in nature and can accommodate a large number of drugs with a wide range of solubilities Improve the oral bioavailability of poorly soluble drugs Enhance the skin permeability of drugs when applied topically provide advantage of usage through various routes viz. oral, parentral, topical, ocular etc. The bilayers of the niosomes protect the enclosed Active pharmaceutical ingredient from the various factors present both inside and outside the body The surfactants used and also the prepared niosomes are biodegradable, biocompatible and non-immunogenic They are osmotically active and stable 7
  8. 8. Disadvantages of Niosome•Aqueous suspension of niosome may exhibit fusion, aggregationleaching or hydrolysis of entrapped drug, thus limiting the shelf lifeof niosome dispersion.• Time consuming• Requires specialized equipment• Inefficient drug loading 8
  9. 9. Structure of Niosomes•Niosomes are microscopic lamellar structures•Basic structural components are  Non ionic surfactant  Cholesterol  Charge inducing molecule•A number of non-ionic surfactants used are: polyglycerol alkyl ether, glucosyl dialkyl ethers, crown ethers, esterlinked surfactants, polyoxyethylene alkyl ether and a series of spans andtweens 9
  10. 10. Non-ionic SurfactantsThe non-ionic surfactants orient themselves in bilayer lattices where the polar or hydrophobic heads align facing aqueous bulk (media) while the hydrophobic head or hydrocarbon segments align in such a way that the interaction with the aqueous media would be minimized. To attain thermodynamic stability, every bilayer folds over itself as continuous membrane i.e. forms vesicles so that hydrocarbon/water interface remains no more exposed. 10
  11. 11. Mainly following types of non-ionic surfactants are used for the formation of niosomes: Alkyl Ethers: L’Oreal described some surfactants for the preparation of niosomes containing drugs/chemicals as  1) Surfactant-I (molecular weight (MW 473)) is C16 monoalkyl glycerol ether with average of three glycerol units.  2) Surfactant-II (MW 972) is diglycerol ether with average of the seven glycerol units.  3) Surfactant III (MW 393) is ester linked surfactant. Other than alkyl glycerol, alkyl glycosides and alkyl ethers bearing polyhydroxyl head groups are also used in formulation of niosomes. Alkyl Esters: Sorbitan esters are most preferred surfactant used for the preparation of niosomes amongst this category of surfactants. Vesicles prepared by the polyoxyethylene sorbitan monolaurate are relatively soluble than other surfactant vesicles. For example polyoxyethylene (polysorbate 60) has been utilized for encapsulation of diclofenac sodium. A mixture of polyoxyethylene-10-stearyl ether : glyceryl laurate : cholesterol (27 : 15 : 57) has been used in transdermal delivery of cyclosporine-A. Alkyl Amides: Alkyl amide (e.g. galactosides and glucosides) have been utilized to produce niosomal vesicles. Fatty Acid and Amino Acid Compounds: Long chain fatty acids and amino acid moieties have also been used in some niosomes preparation. 11
  12. 12. Diff. types of Non-ionic surfactants 12
  13. 13. CholesterolSteroids are important components of the cell membrane and their presence in membrane affect the bilayer fluidity and permeability.Cholesterol is a steroid derivative, which is mainly used for the formulation of niosomes. Although it may not show any role in the formation of bilayer, its importance in formation of niosomes and manipulation of layer characteristics can not be discarded.In general, incorporation of cholesterol affects properties of niosomes like membrane permeability, rigidity, encapsulation efficiency, ease of rehydration of freeze dried niosomes and their toxicity.It prevents the vesicle aggregation by the inclusion of molecules that stabilize the system against the formation of aggregates by repulsive steric or electrostatic forces that leads to the transition from the gel to the liquid phase in niosome systems. As a result of this, the niosome becomes less leaky in nature. 13
  14. 14. Charge inducing moleculeSome charged molecules are added to niosomes to increase stability of niosomes by electrostatic repulsion which prevents aggregation and coalescence. The negatively charged molecules used are diacetyl phosphate (DCP) and phosphotidic acid. Similarly, stearylamine (STR) and stearyl pyridinium chloride are the well known positively charged molecules used in niosomal preparations.Only 2.5-5 mol % concentration of charged molecules is tolerable because high concentration can inhibit the niosome formation 14
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  16. 16. Contrast of Niosomes Vs liposomes Niosome Liposome 1. Less Expensive 1. More expensive 2. Chemically Stable 2. Chemically unstable3. Niosomes are prepared 3. liposomes are prepared from uncharged single- from double-chain chain surfactant phospholipids 4. They do not require 4. They require special special storage and storage, handling & handling purity of natural phospholipid is variable.5. Non ionic drugs carriers 5. The ionic drugs carriers are safer are relatively toxic & unsuitable 16
  17. 17. Similarity of niosomes and liposomes• However Niosomes are similar to liposomes in functionality.• Niosomes also increase the bioavailability of the drug and reduce the clearance like liposomes.• Niosomes can also be used for targeted drug delivery, similar to liposomes.• As with liposomes, the properties of the niosomes depend both- on the composition of the bilayer, and the method of production used. 17
  18. 18. Method of Preparation1. Ether Injection (LUV) Based on the vesicle size, niosomes can be divided into three groups.2. Hand Shaking Method (MLV) These are small unilamellar vesicles (SUV, size=0.025-0.05 μm),3. The “Bubble” Method multilamellar vesicles (MLV, size=>0.05 μm), and large4. Reverse Phase Evaporation (LUV) unilamellar vesicles (LUV, size=>0.10 μm).5. Sonication (SUV)6. Multiple membrane extrusion method7. Trans Membrane pH Gradient Drug Uptake Process (remote Loading) (MLV)8. Microfluidization method (SUV)9. Formation of Niosomes From Proniosomes 18
  19. 19. General steps of Niosome preparation• Hydration of mixture of surfactant/lipid at elevated temperature• Sizing of niosomes• Removal of unentrapped material from vesicles 19
  20. 20. Common stages of all methods of preparation of Niosomes Cholesterol + Non ionic surfactant Dissolve in organic solvent Solution in organic solvent Drying Thin film Dispersion (Hydration) Niosome suspension 20
  21. 21. 1. Ether injection method• This method is based on slow injection of surfactant : cholesterol solution in ether through 14 gauge needle into a preheated aqueous phase maintained at 600C• Vaporization of ether resulting into a formation of ether gradient at ether-water interface which leads to formation of single layered vesicles• Depending upon the conditions used, the diameter of the vesicle range from 50 to 1000 nm 21
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  23. 23. 2. Hand shaking method(Thin film hydration technique)• Surfactant and cholesterol are dissolved in a volatile organic solvent (diethyl ether, chloroform or methanol) in a round bottom flask• The organic solvent is removed under vaccum at room temperature using rotary evaporator leaving a thin layer of solid mixture deposited on the wall of the flask• The dried surfactant film can be rehydrated with aqueous phase at temperature slightly above the phase transition temperature of the surfactant used, with gentle agitation• This process forms large multilamellar niosomes 23
  24. 24. 24
  25. 25. 3. The “Bubble” Method•It is novel technique for the one step preparation of liposomes andniosomes without the use of organic solvents•The bubbling unit consists of round-bottom flask with three neckspositioned in water bath to control the temperature•Water-cooled reflux and thermometer is positioned in the first andsecond neck and nitrogen supply through the third neck• Cholesterol and surfactant are dispersed together in this buffer (pH 7.4)at 70°C, the dispersion mixed for 15 seconds with high shearhomogenizer and immediately afterwards “bubbled at 70°C usingnitrogen gas 25
  26. 26. 4. Reverse Phase Evaporation Technique (REV)•Cholesterol and surfactant (1:1) are dissolved in a mixture of etherand chloroform•An aqueous phase containing drug is added to this and the resultingtwo phases are sonicated at 4-5°C. The clear gel formed is furthersonicated after the addition of a small amount of phosphate bufferedsaline (PBS)•The organic phase is removed at 40°C under low pressure. Theresulting viscous niosome suspension is diluted with PBS and heatedon a water bath at 60°C for 10 min to yield niosomes 26
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  28. 28. 5. Sonication•In this method, an aliquot of drug solution in buffer is added to thesurfactant/cholesterol mixture in a 10-ml glass vial.•The mixture is probe sonicated at 60°C for 3 minutes using a sonicator.•The resultant vesicles are of small unilamellar type niosomes.6. Multiple membrane extrusion method• In this method, a mixture of surfactant, cholesterol and diacetyl phosphate is preparedand then solvent is evaporated using rotary vacuum evaporator to leave a thin film. Thefilm is then hydrated with aqueous drug solution and the suspension thus obtained isextruded through the polycarbonate membrane (mean pore size 0.1 mm) and thenplaced in series up to eight passages to obtain uniform size niosomes.•Good method of controlling niosome size. 28
  29. 29. Sonication method Extrusion method 29
  30. 30. 7. Trans membrane pH gradient (inside acidic) Drug Uptake Process (remote Loading)•Surfactant and cholesterol are dissolved in chloroform• The solvent is then evaporated under reduced pressure to get a thin film on thewall of the round bottom flask•The film is hydrated with 300 mM citric acid (pH 4.0) by vortex mixing.•The multilamellar vesicles are frozen and thawed 3 times and later sonicated. To this niosomal suspension, aqueous solution containing 10 mg/ml of drug is added and vortexed• The pH of the sample is then raised to 7.0-7.2 with 1M disodium phosphate• This mixture is later heated at 60°C for 10 minutes to give niosomes 30
  31. 31. 8. Microfluidization MethodIn this method two fluidized streams (one containing drug and the other surfactant) interact at ultra high velocity, in precisely defined micro channels within the interaction chamber in such a way that the energy supplied to the system remains in the area of niosomes formations. This is called submerged jet principle. It results in better uniformity, smaller size and reproducibility in the formulation of niosomes 31
  32. 32. 9. Formation of Niosomes from Proniosomes•Another method of producing niosomes is to coat a water-solublecarrier such as sorbitol with surfactant• The result of the coating process is a dry formulation. In which eachwater-soluble particle is covered with a thin film of dry surfactant. Thispreparation is termed “Proniosomes”•The niosomes are formed by the addition of aqueous phase at T > T mand brief agitation T = Temperature. Tm = mean phase transition temperature 32
  33. 33. Separation of unentrapped drugsThe removal of unentrapped solute from the vesicles can beaccomplished by various techniques, which include:Gel FiltrationThe unentrapped drug is removed by gel filtration of niosomal dispersion through aSephadex-G-50 column and elution with phosphate buffered saline or normal saline.DialysisThe aqueous niosomal dispersion is dialyzed in a dialysis tubing against phosphatebuffer or normal saline or glucose solutionCentrifugationThe niosomal suspension is centrifuged and the supernatant is separated. The pellet iswashed and then resuspended to obtain a niosomal suspension free from unentrapped 33drug.
  34. 34. Factors affecting the physicochemical properties ofniosomesMembrane Additives Stability of niosomes can be increased by the number of additives into niosomal formulation along with surfactant and drugs. The membrane stability, morphology and permeability of vesicles are affected by numbers of additives e.g. addition of cholesterol in niosomal system increases the rigidity and decreases the drugs permeability through the membraneTemperature of Hydration Shape and size of niosome is also influenced by the hydration temperature. Assembly of the niosomes vesicles is affected by the temperature change of niosomal system. Temperature change can also induce the vesicle shape transformation 34
  35. 35. Properties of Drugs  The drug entrapment in niosomes is affected by molecular weight, chemical structure, hydrophilicity, lipophilicity as well as the hydrophilic lipophilic balance (HLB) value of the drug. Vesicle size may increase due to entrapment of drug. Drug particle interact with the surfactant head groups, which may increase charge on polymer and thus cause repulsion of the surfactant bilayer which leads to increase in vesicle size.Amount and Type of Surfactant  As the HLB value of surfactants like span 85 (HLB 1.8) to span 20 (HLB 8.6) increased, the mean size of niosomes also increases proportionally. It is due to the fact that surface free energy decreases with increase in hydrophilicity of surfactant. Alkyl chain is present in well ordered structure in gel state, while in the liquid state the structure of bilayer is more disordered.  Entrapment efficiency is also affected by phase transition temperature i.e. span 60 having higher TC, provide better entrapment efficiency. Entrapment efficiency of the niosomes is affected by the HLB value for e.g. niosomes have high entrapment efficiency at HLB value 8.6 but HLB value 14 to 17 is 35 not suitable for niosomes formulation
  36. 36. Effect of the nature of drug on the formation of niosomes 36
  37. 37. Cholesterol Content and charge  Hydrodynamic diameter and entrapment efficiency were found to be increased due to cholesterol content in the niosomal bilayer. Cholesterol can act by two ways. First, it can increase the chain order of liquidated bilayer and second, by decreasing the chain order of the gel state bilayer.  Release rate of drug decreases and rigidity of bilayer increases due to high concentration of cholesterol  The presence of charge tends to increase the interlamellar distance between successive bilayers in multilamellar vesicle structure and leads to greater overall entrapped volumeStructure of Surfactants  The geometry of vesicles to be formed from surfactant is affected by its structure, which is related to critical packing parameter (CPP) where V= hydrophobic group volume Ic = the critical hydrophobic group length a0 = the area of hydrophilic head group spherical micelles formed if CPP<0.5, inverted micelles is formed if CPP>1. 37
  38. 38. Method of Preparation  The average size of acyclovir niosomes prepared by hand-shaking process was larger (2.7m m) as compared to the average size of niosomes 1.5m m prepared by ether injection method which may be attributed to the passage of cholesterol and span-80 solution through an orifice into the drug solution. Reverse phase evaporation can be used to produce smaller size vesicles. Vesicles with smaller size and greater stability can be produced by microfluidization method. Niosomes obtained by transmembrane pH gradient (inside acidic) drug uptake process showed greater entrapment efficiency and better retention of drugResistance to Osmotic Stress  Diameter of niosomal vesicles was found to be decreased when niosomal suspension is kept in contact with hypertonic salt solution. There is slow release with slight swelling of vesicles, which is due to inhibition eluting fluids from vesicles, followed by faster release, which may be due to decrease in mechanical strength under osmotic stress 38
  39. 39. Types of NiosomesProniosomes Proniosomes are the niosomal formulation containing carrier and surfactant, which requires to be hydrated before being used. The hydration results in the formation of aqueous niosome dispersion. Proniosomes decreases the aggregation, leaking and fusion problem associated with niosomal formulationAspasomes Combination of acorbyl palmitate, cholesterol and highly charged lipid diacetyl phosphate leads to the formation of vesicles called aspasomes. Aspasomes are first hydrated with water/aqueous solution and then sonicated to obtain the niosomes. Aspasomes can be used to increase the transdermal permeation of drugs. Aspasomes have also been used to decrease disorder caused by reactive oxygen species as it has inherent antioxidant property 39
  40. 40. Vesicles in Water and Oil System (v/w/o) It has been reported that the emulsification of an aqueous niosomes into an oil phase form vesicle in water in oil emulsion (v/w/o). This can be prepared by addition of niosomes suspension formulated from mixture of sorbitol monostearate, cholesterol and solulan C24 (poly-24-oxyethylene cholesteryl ether) to oil phase at 60°C. This results in the formation of vesicle in water in oil (v/w/o) emulsion which by cooling to room temperature forms vesicle in water in oil gel (v/w/o gel). The v/w/o gel thus obtained can entrap proteins/proteinous drugs and also protect it from enzymatic degradation after oral administration and controlled release. The immunogenic properties of v/w/o gel and w/o gel reported that both exhibit immunoadjuvant tendency. In this system aqueous niosomes (v/w) are emulsified into the oily phase 40
  41. 41. Niosomes in Carbopol Gel Niosomes were prepared using drug, spans and cholesterol. The niosomes thus obtained were then incorporated in carbopol-934 gel (1% w/w) base containing propylene glycol (10% w/w) and glycerol (30% w/w). It was observed that the mean flux value and diffusion co-efficient were 5 to 7 times lower for niosomal gel as compared to plain drug gels. Moreover, carrageenan induced paw edema inhibition (i.e. 66.68 ± 5.19%) was higher by niosome formulation as compared to plain gel.Niosomes of Hydroxyl Propyl Methyl Cellulose In this type, a base containing 10% glycerin of hydroxy propyl methyl cellulose was first prepared and then niosomes were incorporated in it. The bioavailability and reduction of paw edema induced by carrageenan was found to be higher by this niosomal system than the plain formulation of flurbiprofen. 41
  42. 42. Characterization of niosomesPhysical characterizationChemical characterizationBiological characterization 42
  43. 43. Physical characterizationSr no. Parameters Analytical methods/Instruments1. Vesicles shape & surface Transmission electron morphology microscopy, Freeze-fracture electron microscopy2. Mean vesicle size and size Dynamic light scattering, distribution zetasizer, (submicron and micron range) Photon correlation spectroscopy, laser light scattering, gel permeation and gel exclusion3. Surface charge Free-flow electrophoresis 43
  44. 44. 4. Phase behavior Freeze-fracture electron microscopy, Differential scanning colorimetery5. Electrical surface potential Zeta potential and surface pH measurements & pH sensitive probes6. Entrapment efficiency Amount entrapped/total amount added*100 44
  45. 45.  Chemical characterization Sr no Parameters Analytical methods/Instruments 1. Cholesterol concentration Cholesterol oxidase assay and HPLC 2. Cholesterol auto-oxidation HPLC and TLC 3. Osmolarity Osmometer 45
  46. 46.  Biological characterization Sr No. Parameters Analytical methods/Instruments 1. Sterility Aerobic or anaerobic cultures 2. Pyrogenicity Limulus Amebocyte Lysate (LAL) test 3. Animal toxicity Monitoring survival rates, histology and pathology 46
  47. 47. Evaluation Parameters (Summary) % Entrapment Efficiency (%EE) Size, Shape and Morphology  Transmission Electron Microscopy (TEM)  Freeze Fractured Microscopy  Optical Microscopy Technique In Vitro Release Study Tissue Distribution/In Vivo Study Stability Study Number of Lamellae Membrane Rigidity Vesicular Surface Charge 47
  48. 48. Drugs and routes of administration used in Niosomes 1. Intravenous Route Ipromide, Vincristine,Indomethacin, Colchicines, Rifampicin, Transferrin, Zidovudine, Cisplantin, amarogentin, Daunorubicin, AmphotericinB. 2. Transdermal Route Flurbiprofen, Piroxicam, Levonorgestrol, Nimeluside, Estradiol, Ketoconazole, Enoxacin, DNA loaded noisome, Cyclosporine, Erythromycin, α interferon. 3. Oral Route Vaccine, Polysaccharide Coated noisome, Cipro floxacin, Insulin. 4. Oncology Route Methotrexate, Doxorubicin, adriamycin. 5. Ocular Route Timolol, cyclopentolate 6. Nasal Route Sumatriptan, Influenza 7.Immunological Adjuvant Bovine serum albumin, Hemoglobin8. For treatment of Leishmaniasis Stilbogluconat 48
  49. 49. Therapeutic applications of NiosomesThe applications of niosomes can be mainly classified into three categories 1) For Controlled Release of Drugs 2) To Improve the Stability and Physical Properties of the Drugs 3) For Targeting and Retention of Drug in Blood Circulation 49
  50. 50. 1)To Prolong the Release Rate of Drugs1.1 For Controlled Release The release rate of drugs like withaferin and gliclazide from the niosomes was found slower as compared to other dosage forms1.2 In Ophthalmic Drug Delivery Experimental results of the water soluble antibiotic gentamicin sulphate showed a substantial change in the release rate. Beside this, the percent entrapment efficiency of gentamicin sulphate was altered when administered as niosomes. Also, as compared to normal drug solution, niosomes of drug show slow release Niosomal formulation containing timolol maleate (0.25%) prepared by chitosan coating exhibited more effect on intra ocular tension with fewer side effects as compared to the marketed formulation. 50
  51. 51. 2) To Improve the Stability and Physical Properties of the Drugs2.1 To Increase Oral Bioavailability  With the formulation of niosomes, the oral bioavailability of the acyclovir as well as griseofulvin was increased as compared to the drug alone. Similarly, the absorptivity of poorly absorbed peptide and ergot alkaloid can be increased by the administration in the bile duct of rats when administered as micellar solution together with the POE-24-cholesteryl ester2.2 For Improvement of Stability of Peptide Drugs  8-arginin vasopressin, 9-glycinamide-ω  The in vitro release of insulin from niosomes formulated by span 40 and span 60 in simulated intestinal fluid was lower than the niosomes formulated by span 20 and span 80.  Niosomes prepared by the span 60 has high resistance against proteolytic enzyme and exhibit good stability in storage temperature and in presence of sodium deoxycholate 51
  52. 52. 2.3 To Promote Transdermal Delivery of Drugs  Many drugs such as lidocaine, estradiol, cyclosporine etc. are used for topical and transdermal drug delivery system by formulating them as niosomes  The niosomes of natural compound, ammonium glycyrrhizinate were formulated for effective anti-inflammatory activity using new non-ionic surfactant, bola surfactat-span 80-cholesterol (2 : 3 : 1 ratio).  Experimental study showed that the bola niosomes were able to promote the intracellular uptake of ammonium glycerrhizinic acid2.4 As a Tool for Improvement of Stability of Immunological Products  Important tool for immunological selectivity, low toxicity and more stability of the incorporated active moiety2.5 To Improve Anti-inflammatory Activity  Niosomal formulation of diclofenac sodium prepared with 70% cholesterol showed greater anti-inflammatory effect as compared to the free drug  Similarly, nimesulide and flurbiprofen showed greater activity than the free drug 52
  53. 53. 3.For Targeting and Retention of Drug in Blood Circulation3.1 For Increased Uptake by A431 Cells [a model cell line (epidermoid carcinoma) used in biomedical research]  Chitosan based vesicles incorporating transferrin and glucose as ligand have been reported. These vesicles bind CoA (co-A) to their surface. Chitosan containing vesicles are then taken up by A431 cells and the uptake was found to be enhanced by transferrin.3.2 For Liver Targeting  Methotrexate was reported to be selectively taken up by liver cells after administration as a niosomal drug delivery system.3.3 To Improve the Efficacy of Drugs in Cancer Therapy  Niosomes can also be used as a suitable delivery system for the administration of drugs like 5-FU.  Niosomes of doxorubicin prepared from C16 monoalkyl glycerol ether with or without cholesterol, exhibited an increased level of doxorubicin in tumor cells, serum and lungs, but not in liver and spleen  Niosomal preparation of methotrexate exhibited greater antitumor activity as compared to plain drug solution 53
  54. 54. 3.4 In Treatment of Localized Psoriasis  In the treatment of localized psoriasis, niosomes of methotrexate taking chitosan as polymer have shown promising results3.5 In Leishmaniasis  The leishmaniasis parasite mainly infects liver and spleen cells. The commonly used drugs, antimonials, may damage the body organ like heart, liver, kidney etc. The efficiency of sodium stibogluconate has been found to be enhanced by incorporation in niosomes. The additive effect was observed for two doses given on successive days. Moreover, the distribution of antimony in mice showed the higher level of antimony in liver after its intravenous (i.v.) administration via niosomes drug formulation.3.6 In Diagnostic Imaging  It has been studied that niosomes can also act as a carrier radiopharmaceuticals and showed site specificity for spleen and liver for their imaging studies using 99mTc labelled DTPA (diethylene triamine pentaacetic acid) containing niosomes.  Conjugated niosomal formulations of gadobenate with (N-palmitoyl-glucosamine, NPG), PEG 4400 and both PEG and NPG can be used to increased tumor targeting of a paramagnetic agent 54
  55. 55. 3.7 Carrier for Haemoglobin  Niosomes play an important role as a carrier for haemoglobin. The niosomal haemoglobin suspension was found to give superimposable curve on free haemoglobin curve Usefulness of Niosomes in Cosmetics Niosomes of N-acetyl glucosamine are prepared due to its potential in the delivery of hydrophilic and hydrophobic drugs in topical form and improved penetration into the skin. Prepared formulations improved the extent of drug localized in the skin, as needed in hyperpigmentation disorders. Elastic niosomes showed increased permeation through the skin which will be beneficial for topical anti-aging application. suitable for skin moisturising and tanning products Niosomes were prepared as possible approach to improve the low skin penetration and bioavailability shown by conventional topical vehicle for minoxidil. Niosomes with added solubilizers enhanced the permeation of ellagic acid (a potent antioxidant phytochemical substance which has limited use due to poor biopharmaceutical properties, low solubility and low permeability) into the skin with 55 increased efficacy of ellagic acid
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  59. 59. Marketed productsLancome has come out with a variety of anti-ageing products which are based on niosome formulations. L’Oreal is also conducting research on anti-ageing cosmetic products. A picture of the Lancome anti-ageing formulation is below LANCOME FOUNDATION CREAM NIOSOME+ 59
  60. 60. Future Prospects• Niosomes represent a promising drug delivery module.• There is lot of scope to encapsulate toxic anti-cancer drugs, anti infective drugs, anti AIDS drugs, anti-inflammatory drugs, anti viral drugs, etc. in niosomes and to use them as promising drug carriers to achieve better bioavailability and targeting properties and for reducing the toxicity and side effects of the drugs.• The ionic drugs carriers are relatively toxic and unsuitable whereas niosomal carriers are safer. 60
  61. 61. • In addition, handling and storage of niosomes require no special conditions.• Vesicular drug carriers like niosomes can be transported by microphages which are known to infiltrate tumour cells.• It may be possible to take advantage of these activated macrophage system in delivering the anti tumour agents within vesicles more quantitatively to tumour sites. 61
  62. 62. ConclusionIn nutshell, as a drug delivery device, compared to liposomes, niosomes are osmotically active and are quite stable chemically by their own as well as improve the stability of the drug so entrapped and delivered. They do not require special conditions for handling, protection or storage and industrial manufacturing. Beside this, they offer flexibility in structural characteristics (composition, fluidity, size), and can be designed as desired.Niosomes offer various advantages over other drug delivery devices and have found applicability in pharmaceutical field.It was thus concluded that niosomes are very effective drug delivery tools for incorporation/targeting of various therapeutically active moieties and the onus lies on future scientists to effectively harness its potential in diverse application areas for the benefit of mankind. 62
  63. 63. References1. Sanjay K. Jain and N.K. Jain Controlled and novel drug deliverysystem2. Dr. Rakesh S. Patel niosomes as a unique drug delivery system,www.pharmainfo.net3. Mithal, B. M., A text book of pharmaceutical formulation, 6 thEdn., vallabh prakashan, 6, 306-3074. International journal of pharmaceutical Science andNanotechnology volume 1,issue 1, April-June 20085. Shailendra Kumar Singh et.al, Niosomes: A Controlled andNovel Drug Delivery System, Biol. Pharm. Bull. 34(7) 945—953(July, 2011) 63

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