Niosomes preparation

The delivery of doxorubicin to the SI80 sarcoma (tumor) in mice, using niosomes as a carrier, has been studied by Rogerson [168]. Much higher tumor drug levels were reported with niosomes prepared using the nonionic surfactant I and 50% cholesterol than with free... 

Niosomes (prepared using surfactant I and surfactant I, II, or III and 30% cholesterol) containing stibogluconate have been as effective as the corresponding liposomal drugs in the visceral leishmaniasis model. Free drug showed reduced efficacy [169],... 

A number of works investigated the interaction between niosomes and human skin. With niosomes prepared from Ci2 alcohol polyoxyethylene ether and cholesterol, vesicular structures of about 100 nm size have been observed between the first and second layers of human corneocytes 48 h after incubation as well as in the deeper strata of the skin [37], The authors concluded that the structures visualized in the deeper regions could be vesicles reorganized from individual molecules that penetrated the skin. In another study, electron micrographs illustrated that niosomes containing surfactants and cholesterol affected only the most superficial corneocytes. Moreover, two-photon fluorescence microscopy confirmed that fluorescent probe encapsulated in niosomes was confined to the intercellular spaces within the apical stratum corneum layers [56]. 

Aggarwal, D., A. Garg, and I.P. Kaur. 2004. Development of a topical niosomal preparation of acetazolamide Preparation and evaluation. J Pharm Pharmacol 56 1509. 

Fig. 7. (a) The release of CF from exhaustively dialysed polyhedryl niosomes. =C16G2, solulan C24 (91 9) A=C16G2, solulan C24 (95 5) (b) The release of nicotinamide dinucleotide from polyhedral niosomes prepared from C16G2,solulan (91 9) at 24 °C. Arrow points the time at which the temperature is raised to 37 °C for 10 min... 

Niosomes are non-ionic surfactant vesicles. They have been used to develop a vaccine-delivery system by peroral and oral routes. Ovalbumin was encapsulated in various lyophilized niosome preparations consisting of sucrose esters, cholesterol, and dicetyl phosphate. Encapsulation of ovalbumin into niosomes consisting of 70% stearate sucrose ester and 30% pal-mitate sucrose ester (40%i mono-, 60% di/triester) resulted in a significant increase in antibody titers in serum, saliva, and intestinal washings. ... 

Liposomes and Niosomes Prepared With Native or Water-soluble Modified CyDs... 

BayindirZS, Ytrksel N (2010) Characterization of niosomes prepared with various nonionic sttr-factants for pacUtaxel oral delivery. J Pharm Sci 99(4) 2049-2060... 

Baillie, A.J. et al.. The preparation and properties of niosomes-non-ionic surfactant vesicles, J. Pharm. Pharmacol., 37, 863, 1985. 

The methods for preparation of niosomes are similar and as complicated as those used for liposomes. One of the most frequently utilized techniques consists of the hydration of a mixture of the surfactant-lipid at elevated temperature followed by optional size reduction (by sonication, extrusion, homogenization, etc.) to obtain a homogeneous colloidal dispersion and separation of the unentrapped drug [36,40,41,52,55],... 

The stability of various niosomal formulations depends on factors such as preparation methods, storage temperature, the encapsulated drug, the surfactants, and additive mixture [41,52,64,65], It may be possible to stabilize niosomes by a variety of methods such as the use of membrane-spanning lipids, the interfacial polymerization of surfactant monomers in situ, addition of polymerized surfactants, cholesterol, steric and electrostatic stabilizers to the formulation [41,52]. In general, vesicle aggregation may be prevented by inclusion of... 

Yoshioka, T., B. Sternberg, and A.T. Florence. 1994. Preparation and properties of vesicles (niosomes) of sorbitan monoesters (span-20, span-40, span-60 and span-80) and a sorbitan triester (span-85). Int J Pharm 105 1. 

Shinkai and coworkers prepared numerous novel amphiphilic crowns (Shinkai, 1990) and incorporated them into membranes, formed membranes from them, or used them in liquid crystalline assemblies to control properties (He et al., 1990). Interest in this area continues. Four chiral amphiphilic crown ethers were recently reported that recognize enantiomeric amino acids when examined as Langmuir films (Badis et al., 2004). Finally, it is interesting to note that liposomes formed from amphiphiles (e.g., crown ethers) having neutral headgroups (i. e., niosomes) have been studied as drug delivery vehicles (Uchegbu and Vyas, 1998). 

A transdermal flurbiprofen formulation has been prepared from flubiprofen span 60, cholesterol, DCP (46 50 4) niosomes incorporated within an HPMC semi-solid base containing 10 % glycerin [155]. The in vitro characterization of the formulation is not given, however this formulation was evaluated in a rat inflammation model. 

Uchegbu IF, Duncan R. Niosomes containing N-(2-hydroxy-propyl) methacrylamide-doxorubidn (PKl) effect of method of preparation and choice of surfactant on niosome characteristics and a preliminary study of body distribution. Int J Pharm 1997 155 7-17. 

Sathali et al. formulated a topical gel containing clobetasol propionate niosomes to prolong the duration of action and prevent side effects. The clobetasol propionate niosomes were prepared by altering the ratio of various non-ionic surfectants (Span 40,60, and 80) to cholesterol by the thin film hydration method. The in vivo results showed that the niosomal gel had a sustained as well as a prolonged action. 

Terzano et al developed Polysorbate 20 niosomes containing beclomethasone dipropionate for pulmonary delivery to patients with chronic obstructive pulmonary disease. Singh et prepared niosomes containing the anti-inflammatory drug nimesulide and tested its physico-chemical properties including stability and in vitro release. It was shown that in vitro sustained drug release can be achieved with this approach. The research literature for niosomes in ocular drug delivery has been reviewed by Kaur et al." ... 

Differences in characteristics exist between liposomes and niosomes, especially since niosomes are prepared from uncharged single-chain surfactant and cholesterol whereas liposomes are prepared from double-chain phospholipids (neutral or charged). 

There are some potential applications in which the external phase is nonaqueous. Florence and co-workers (79, 80) and Albert et al. (81) described systems in which the aqueous suspension of vesicles are dispersed in the continuous oil phase. The technique was exercised both for the study of its use in drug-delivery systems and as immunological adjuvants, as well as an intrinsically interesting colloidal system. The system is an emulsion prepared from a dispersion of niosomes in water, re-emulsified in an oil using a surfactant mixture of low HUB to achieve a stable W/0 emul-... 

Baillie AJ, Florence AT, Hume L, Muirhead GT, Rogerson A (1985) The preparation and properties of niosomes—non-ionic surfactant vesicles. J Pharm Pharmacol 37(12) 863-868... 

Higher chemical stability. Niosomes are in most case prepared from saturated alkyl chains containing ether linkages. This results in a higher stability of the surfactant in comparison to phospholipids, which are easily hydrolysed due to the presence of ester bonds in their stmcture. 

Figure 28.7 Chemical structure of non-ionic surfactants and associated compounds used in the preparation of niosomes.

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