Nanoliposomes All categories of drugs like hydrophobic, amphipathic and

Nanoliposomes have ability to approach
merely the precise cells, which is a prime requisite to accomplish preferred
drug concentration at the target spot so that the undesirable effects can be
minimized and optimum therapeutic effectiveness of drug on healthy cells and
tissues can be achieved. They can also to protect the active moiety in blood
circulation and deliver it at the targeted site at a sustained pace 14. Thus,
nanoliposomes as a carrier helped in improving the therapeutic index of drugs
by selective and controlled drug
delivery, by declining
the exposure of lethal drugs to susceptible tissue, and by controlling the drug
pharmacokinetics and biodistribution. All categories of drugs like hydrophobic,
amphipathic and hydrophilic drugs are suitably delivered by using nanoliposomes
as a carrier as it carried both lipophilic and hydrophilic environment in one
system (27-29). Moreover, nanoliposomes have found imminent applications in the
various streams of nanotechnology like gene delivery, cosmetics, agriculture,
food technology, diagnosis and cancer therapy. High production cost, oxidation
and hydrolysis of phospholipids, seepage and blending of encapsulated
drug/molecules, less stability, small half-life, and squat solubility are some
of the precincts of nanoliposomes. However, the instability of nanoliposomes in vitro and in vivo confines their application. The nanoliposomes have tendency
to amassed and degrade, which causes seepage of encapsulated material during
storage and washout rapidly through the system after intravenous injection. Literature
suggested that, amid various factors that influence the stability of nanoliposomes,
carrier’s surface characters like fluidity, lipophilicity, and charge are of
great significance. Therefore, the minute alteration in carrier’s surface with
polymers having required properties, we can easily improve the in vitro and in vivo stability of nanoliposomes.

Coating with polymers of desired
properties is an assuring approach of altering the surface characteristics of
nanoliposomes, in which the nanoliposomes suspension was mixed simply with a
polymer solution. Polymer coating enhanced the stability of nanoliposomes during
storage due to the long-range mutual repulsion between adjacent bilayers. Various
natural polymers like polysaccharides and synthetic polymers like polyvinyl
alcohol, polyethylene and polyacrylamide have been used to amend the surface character
of nanoliposomes which ultimately also improve the stability of nanoliposomes.  Amid which chitosan is a positively charged
polysaccharide and can be used to increase and modify the surface characters of
nanoformulations, is also found to have a promising future in the medical and
pharmaceutical fields.

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Chitosan comprised mainly of
glucosamine units and due to existence of amino groups it acts like a
polycationic polymer. It is N-deacetylated derivative of chitin with anti-in?ammatory
and antioxidant properties Qiao
et al., 2011, Cao et al., 2016.
Tissue engineering, obesity control and drug development are its several impaortant
applications. During new drug formulation it used most widely as being biodegradable
and biocompatible it also provide a protective capsule like safeguard to drug
molecule Mady and
Darwish, 2010. Its chemical
configuration and various suitable features like abundance, hydrophobicity,
antimicrobial activity, low toxicity, biocompatibility, and biodegradability made
chitosan an important ingredient to be used in the preparation various modified
formulation and carriers like microsphere, microfilme, nanoparticles, films,
gels. As a carrier to entrapped and release active ingredient, it found
applications in various fields like cosmetics, pharmaceuticals, food and
biotechnology. Literature suggested that various authors had used chitosan or allied
polymers as a coating material for nanoformulations for targeting purposes and for
improving their stability towards release of active moeity Dong and Rogers, 1991. We recognized that suitable
combination of the polymer based and lipid-based systems could amalgamate the
advantages and diminish the disadvantages of each system, and thus lead to development
of 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 and
modified emulsification and ultrasonication (MEU) method and then, both the
preparations were coated with different concentrations of chitosan solutions.
Then, the effects of different concentration of chitosan solution on zeta
potential, particle size, and in vitro
drug release rate were studied. The transmission electron microscopy, FTIR studies,
DSC analysis, particle size and zeta potential studies were used to investigate
presence of chitosan coating on nanoliposomes. The characteristics of uncoated
and chitosan-coated nanoliposomes were studied to develop and further optimize nanoliposomes
that are directed for their systemic pharmacological purposes.Nanoliposomes were prepared by reverse-phase
evaporation (REV) method and modified emulsification and ultrasonication (MEU) method.
In reverse-phase evaporation method, soya lecthin and cholestrol were dissolved
in diethyl ether and gefitinib was dissolved in distilled water. The mixing of
organic phase and aqueous phase was done in ratio (3:1, v/v), and a lipid film
was prepared under reduced pressure at 40 ?C, using a rotary evaporator. Then
10 ml phosphate buffer solution (0.10 M, pH 7.0, PBS) containing Tween 80 was added
under a stream of nitrogen. Nanoliposomes were obtained by reducing the size of
nanoliposomes using ultrasonication with a probe sonicator in an ice bath with
1s ON, 1s OFF intervals, for a total period of 10 min Ding et al., 2011.

In modified emulsification and ultrasonication
method, gefitinib was liquefied in anhydrous ethanol to obtain a required
concentration of gefitinib ethanolic solution. The ethanolic solution of
gefitinib containing lipid phase was heated on a water bath at 60 ?C. Tween 80
was dissolved in 10ml of phosphate buffer of pH 6.8 and maintained at the same
temperature as the aqueous phase. The aqueous phase was added dropwise into the
non-aqueous phase under magnetic stirring. The consequential preparation was
stirred for another 10 min, and then ultrasonication was done. Then, the
preparation placed on an ice bath and diluted to a desired volume. Finally the
preparation was filtered through a 0.22µm membrane filter Guan et al., 2011.

 

Both the preparations were
centrifuged seperately. The formed pellet was washed with sterile double
distilled deionised water and re-centrifuged; this step was repeated four times
and the pellet then re-suspended in an appropriate amount of sterile double
distilled deionised water.

For chitosan-coated nanoliposomes,
an appropriate amount of percentage (w/v) chitosan solution was added drop wise
to the nanoliposomal suspension under magnetic stirring at room temperature.
After addition of chitosan, the mixture was left to stir for approximately 1 h
and then incubated overnight at 4 ?C Mady and Darwish, 2010, Shin et al.,
2013.

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