Nanoliposomes have ability to approachmerely the precise cells, which is a prime requisite to accomplish preferreddrug concentration at the target spot so that the undesirable effects can beminimized and optimum therapeutic effectiveness of drug on healthy cells andtissues can be achieved. They can also to protect the active moiety in bloodcirculation and deliver it at the targeted site at a sustained pace 14. Thus,nanoliposomes as a carrier helped in improving the therapeutic index of drugsby selective and controlled drugdelivery, by decliningthe exposure of lethal drugs to susceptible tissue, and by controlling the drugpharmacokinetics and biodistribution. All categories of drugs like hydrophobic,amphipathic and hydrophilic drugs are suitably delivered by using nanoliposomesas a carrier as it carried both lipophilic and hydrophilic environment in onesystem (27-29). Moreover, nanoliposomes have found imminent applications in thevarious streams of nanotechnology like gene delivery, cosmetics, agriculture,food technology, diagnosis and cancer therapy.
High production cost, oxidationand hydrolysis of phospholipids, seepage and blending of encapsulateddrug/molecules, less stability, small half-life, and squat solubility are someof the precincts of nanoliposomes. However, the instability of nanoliposomes in vitro and in vivo confines their application. The nanoliposomes have tendencyto amassed and degrade, which causes seepage of encapsulated material duringstorage and washout rapidly through the system after intravenous injection. Literaturesuggested that, amid various factors that influence the stability of nanoliposomes,carrier’s surface characters like fluidity, lipophilicity, and charge are ofgreat significance. Therefore, the minute alteration in carrier’s surface withpolymers having required properties, we can easily improve the in vitro and in vivo stability of nanoliposomes.Coating with polymers of desiredproperties is an assuring approach of altering the surface characteristics ofnanoliposomes, in which the nanoliposomes suspension was mixed simply with apolymer solution.
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Polymer coating enhanced the stability of nanoliposomes duringstorage due to the long-range mutual repulsion between adjacent bilayers. Variousnatural polymers like polysaccharides and synthetic polymers like polyvinylalcohol, polyethylene and polyacrylamide have been used to amend the surface characterof nanoliposomes which ultimately also improve the stability of nanoliposomes. Amid which chitosan is a positively chargedpolysaccharide and can be used to increase and modify the surface characters ofnanoformulations, is also found to have a promising future in the medical andpharmaceutical fields. Chitosan comprised mainly ofglucosamine units and due to existence of amino groups it acts like apolycationic polymer.
It is N-deacetylated derivative of chitin with anti-in?ammatoryand antioxidant properties Qiaoet al., 2011, Cao et al., 2016.Tissue engineering, obesity control and drug development are its several impaortantapplications.
During new drug formulation it used most widely as being biodegradableand biocompatible it also provide a protective capsule like safeguard to drugmolecule Mady andDarwish, 2010. Its chemicalconfiguration and various suitable features like abundance, hydrophobicity,antimicrobial activity, low toxicity, biocompatibility, and biodegradability madechitosan an important ingredient to be used in the preparation various modifiedformulation and carriers like microsphere, microfilme, nanoparticles, films,gels. As a carrier to entrapped and release active ingredient, it foundapplications in various fields like cosmetics, pharmaceuticals, food andbiotechnology. Literature suggested that various authors had used chitosan or alliedpolymers as a coating material for nanoformulations for targeting purposes and forimproving their stability towards release of active moeity Dong and Rogers, 1991. We recognized that suitablecombination of the polymer based and lipid-based systems could amalgamate theadvantages and diminish the disadvantages of each system, and thus lead to developmentof new system carrying reward of both systems Dai et al., 2006.
In the current work,nanoliposomes were prepared by using reverse-phase evaporation (REV) method andmodified emulsification and ultrasonication (MEU) method and then, both thepreparations were coated with different concentrations of chitosan solutions.Then, the effects of different concentration of chitosan solution on zetapotential, particle size, and in vitrodrug release rate were studied. The transmission electron microscopy, FTIR studies,DSC analysis, particle size and zeta potential studies were used to investigatepresence of chitosan coating on nanoliposomes. The characteristics of uncoatedand chitosan-coated nanoliposomes were studied to develop and further optimize nanoliposomesthat are directed for their systemic pharmacological purposes.Nanoliposomes were prepared by reverse-phaseevaporation (REV) method and modified emulsification and ultrasonication (MEU) method.In reverse-phase evaporation method, soya lecthin and cholestrol were dissolvedin diethyl ether and gefitinib was dissolved in distilled water. The mixing oforganic phase and aqueous phase was done in ratio (3:1, v/v), and a lipid filmwas prepared under reduced pressure at 40 ?C, using a rotary evaporator. Then10 ml phosphate buffer solution (0.
10 M, pH 7.0, PBS) containing Tween 80 was addedunder a stream of nitrogen. Nanoliposomes were obtained by reducing the size ofnanoliposomes using ultrasonication with a probe sonicator in an ice bath with1s ON, 1s OFF intervals, for a total period of 10 min Ding et al., 2011. In modified emulsification and ultrasonicationmethod, gefitinib was liquefied in anhydrous ethanol to obtain a requiredconcentration of gefitinib ethanolic solution. The ethanolic solution ofgefitinib containing lipid phase was heated on a water bath at 60 ?C. Tween 80was dissolved in 10ml of phosphate buffer of pH 6.
8 and maintained at the sametemperature as the aqueous phase. The aqueous phase was added dropwise into thenon-aqueous phase under magnetic stirring. The consequential preparation wasstirred for another 10 min, and then ultrasonication was done. Then, thepreparation placed on an ice bath and diluted to a desired volume.
Finally thepreparation was filtered through a 0.22µm membrane filter Guan et al., 2011. Both the preparations werecentrifuged seperately.
The formed pellet was washed with sterile doubledistilled deionised water and re-centrifuged; this step was repeated four timesand the pellet then re-suspended in an appropriate amount of sterile doubledistilled deionised water.For chitosan-coated nanoliposomes,an appropriate amount of percentage (w/v) chitosan solution was added drop wiseto the nanoliposomal suspension under magnetic stirring at room temperature.After addition of chitosan, the mixture was left to stir for approximately 1 hand then incubated overnight at 4 ?C Mady and Darwish, 2010, Shin et al.,2013.