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Hypothesis Due to the well-know surfactant-like properties of diclofenac sodium (DS), vesicular systems consisting exclusively of DS, named diclosomes , were designed with the aim to minimize or avoid the use of other excipients and to improve the formulation biocompatibility. Experiments Diclosomes were designed and characterized in terms of dimensions, polydispersity index, ξ-potential, drug retained, stability as a function of storage time and ex-vivo percutaneous permeation profiles. Additionally, diclosomes were incorporated into gel dosage forms and their performance in terms of permeation enhancement were evaluated. Findings DS was found to form nanosized vesicular systems, both alone and in presence of cholesterol. Increasing hydrophobicity (due to the presence of cholesterol) resulted in smaller vesicles, always spherical and homogeneous in shape. Permeation of DS from free solution was found to be lower respect to ones obtained for all diclosomal formulations, allowing these aggregates to be considered as percutaneous permeation enhancers. DS permeated from diclosomal gels was higher than that obtained with traditional niosomal gel, DS plain gel and commercial specialty Voltaren Emulgel ® 1%, while containing a considerably lower drug amount. [ABSTRACT FROM AUTHOR]

The loading of chemotherapics into smart nanocarriers that simultaneously possess more than one useful property for specifically targeting a tumor site improves their therapeutic effectiveness, reducing their side effects. Hence, we proposed a combined approach for the treatment of human breast cancer (BC) consisting of the co-encapsulation of doxorubicin and curcumin or doxorubicin and quercetin into multifunctional niosomes, which results in prolonged blood circulation and an ability to spontaneously accumulate at the tumor site (passive target) and to recognize and bind the tumor cells through dual ligand-receptor interactions (active target). The drug-loaded vesicles showed high stability and good capability of loading doxorubicin and antioxidants alone or in combination. Their diameter was around 400 nm. The drugs released from the vesicles were found to be controlled and sustained for over 24 h, with a strong dependence on the co-presence of the loaded molecules. Transferrin and/or folic acid were conjugated on the external surface of the niosomes as ligands, considerably improving the cellular uptake into MCF-7 and MDA-MB-231 malignant cells when compared with the uptake of nonconjugated samples. In vitro evaluation of anticancer activity demonstrated the strong potential of niosomes loaded with a doxorubicin/curcumin combination as useful devices in breast tumor treatment. These features hold great promise for the development of multifunctional devices that combine several advantages such as biocompatibility, stealth properties, loading capability, and active targeting, moving toward the development of more specific and efficient carriers for personalized tumoral therapy. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the transdermal permeation of sulfadiazine sodium, employing synergistic combination of surfactants (in the form of niosomes) and additives with different number of hydroxylic groups, (following referred to as “alcohol”), as component of the bilayer. In particular the effect of different concentration of each alcohol (ethanol, propylene glycol or glycerol, from 5%, to 40% v/v) on niosomes size and distribution, drug entrapment efficiencies and ex vivo drug percutaneous permeation were evaluated, identifying formulations giving the best performances. The findings revealed that the presence of alcohol critically affect the physico-chemical properties of niosomes, with regards to dimensions, drug encapsulation and permeation. Vesicular size increased with the amount of alcohol and at the same alcohol concentration, follow the sequence ethanol > propylene glycol > glycerol. Loaded niosomes were larger than empty ones. Low E % values were found for ethanol, even less in propylene glycol and glycerol based samples, confirming that the chemical structure of the alcohol and its physico-chemical properties, affected the sulfadiazine entrapment efficiency. The comparative evaluation of percutaneous permeation profiles showed that the cumulative amount of permeated drug increases with alcohol concentration up to 20% v/v. Higher concentration (40% v/v) resulted in a strong decrease of the potential skin permeation. Best performances were obtained with glycerol. In all cases ex vivo sulfadiazine percutaneous permeations are controlled and improved respect to the corresponding free drug solutions and traditional niosomes used as controls. [ABSTRACT FROM AUTHOR]

Highlights: [•] Niosomes from glucuronic acid-based surfactant containing doxorubicin or 5FU were prepared. [•] Vesicles were found to encapsulate and release in a prolonged manner both doxorubicin and 5FU. [•] Low toxicity was observed, performing hemolytic tests. [ABSTRACT FROM AUTHOR]

Abstract: We designed novel niosomes based on alkyl glucopyranoside surfactants and containing methotrexate as anticancer drug, to be used in the pharmaceutical field. The effects of surfactants with chains of different length on niosome size and their distribution, drug entrapment efficiencies and in vitro drug release were determined. Systems made of alkyl glucopyranosides and cholesterol form vesicles whose average size scales with the alkyl chains length of such surfactants. Vesicles size ranges between 300 and 500nm, with low polydispersity index. In addition, the hemolytic activity of alkyl glucopyranosides as surfactant solutions or vesicular formulations was studied and compared, to identify possible structure–activity relationships. High methotrexate entrapment efficiency was obtained, confirming significant interactions between the drug and the niosomal matrices. After 24h the amount of methotrexate released from niosomal formulations is effectively delayed, compared to the free drug in solution. Hemolytic tests show that sugar-based surfactants are more hemolytic the longer is their alkyl chain. When the surfactants are in vesicular form, the reverse behavior holds. It was also inferred that vesicle formation reduces the surfactant toxicity. These niosomal formulations can be used as methotrexate delivery systems in anticancer therapy. [Copyright &y& Elsevier]

Abstract: In chemotherapy the magnetic drug targeting to a specific organ or tissue is proposed on the assumption that magnetic fields are harmless to biological systems. In this light we have vehiculated doxorubicin as model drug by novel magneto-niosomes in order to evaluate the physico–chemical properties of the obtained formulations and the in vitro release profile. Tween 60 and Pluronic L64 have been used as surfactants and the formulation cytotoxicity has been performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolum bromide and trypan blue dye esclusion tests. Results show that niosome dimensions and doxorubicin entrapment efficiencies are influenced by bilayer composition. In addition, formulations are able to control the deliver and release of the drug active form in a retarded manner. No additional toxicity, due to the encapsulation of ferrofluid into niosomes core, has been detected. [Copyright &y& Elsevier]

Abstract: The development of advanced biomaterials and drug-delivery systems has had a significant impact on our ability to treat several diseases. A new study was performed on niosomal formulations obtained from a mixture of commercial surfactants (Tween 80 and Span 80) to be applied topically for the release of Capsaicin. Capsaicin is the pungent principle of red pepper and it has a variety of pharmacological actions on the cardiovascular, respiratory and nervous systems. Niosomal carriers were prepared using a particular ratio between surfactants, to obtain systems with a specific HLB (10,12,14) and characterized in terms of dimension, morphology and their drug entrapment efficiency. Niosomes were compared to microemulsions prepared from the same surfactants in the same ratio, to evaluate their possible use in transdermal drug delivery. As regards the in vitro percutaneous permeation of Capsaicin from both microemulsions and niosomal formulations, it was carried out using diffusion Franz cells. The results indicate that niosomes could better promote the transdermal delivery of Capsaicin, with respect to microemulsions, even if both carriers could be an effective vehicle for topical delivery of this drug. [Copyright &y& Elsevier]

Abstract: The central motivation for this study was to evaluate if the increased hydrophilic drug permeation across the skin, which is always observed in presence of vesicular systems, is dependent on the structural organization of niosomes, that are used to transport the active molecules, or if it is only dependent on the surfactant dual nature. To answer this question, non-ionic surfactants belonging to the class of Pluronic and sucrose esters were used both as components of niosomal systems or in the form of sub-micellar solutions. The obtained niosomes were characterized by their entrapment efficiency, size and morphology. The enhancing effect of niosomes on the ex vivo percutaneous penetration of a model drug was investigated using a Franz-type diffusion chamber and compared to that obtained by using sub-micellar solution of surfactant or achieving pretreatment of the skin with surfactants’ sub-micellar solution or empty niosomes. The results suggest that the surfactants used in this study could be considered as percutaneous permeation enhancers only when they are in the form of drug-loaded vesicular systems: no percutaneous promotion was achieved by using sub-micellar solution containing free Sulfadiazine sodium salt or performing pretreatment with empty niosomes or sub-micellar solutions of the surfactant. In our experiments, only niosomes act as effective transdermal drug delivery systems. [Copyright &y& Elsevier]

Abstract: The objectives of our study were to evaluate the ability of Pluronic L64 surfactant to give niosomal systems alone or after its functionalization with acrylic groups. The achieved formulations were tested for the percutaneous permeation of Sodium Diclofenac as model drug. In vitro experiments were conducted by Franz diffusion cells, using rabbit ear skin. Data recorded over 24h were compared with those obtained from the drug solution, as control. In addition, the stability of niosomes was improved polymerizing the acryloyl groups of the monomers, because, as reported in the literature, polymerized vesicles maintain their shape for long periods of time, and show remarkable increase in drug encapsulation efficiency. Mean vesicles diameter, drug entrapment efficiency, percutaneous permeation and release profiles were investigated for all vesicles with different composition. The results indicated an increase in mean vesicles diameter and entrapment efficiency with the increase of polymerizable moieties amount. These properties were found to be more evident when the vesicles were polymerized. In addition cytotoxic effects were estimated. The results of this study showed that niosomes based on commercial, functionalized or a mixture of both Pluronic L64 surfactants can be used to achieve retarded release and to enhance the permeation of Sodium Diclofenac, without incurring unacceptable toxicity. [Copyright &y& Elsevier]

Abstract: A commercial sucrose cocoate surfactant was used to obtain a new vesicular system for transdermal drug delivery. The preparation, the dimensional and morphological characterizations and the skin permeation profile of these new niosomes were evaluated. Moreover we studied the possible employment of mixture of sucrose cocoate and cholesterol at different weigh ratios for the vesicles preparation and we analyzed the influence of cholesterol on niosomes properties. Diclofenac and Sulfadiazine were used as model drugs. Results suggest that sucrose cocoate was able to form vesicles in the presence or not of cholesterol and the addition of cholesterol leads to a variation of size: larger vesicles were obtained in the absence of cholesterol both in empty and drug-loaded niosomes. All vesicles were spherical and regular in shape. In vitro skin permeation profiles were significantly higher than the free drug solution, indicating the favourable relations between skin and niosomes. The faster release of the drug was found for niosomes with no cholesterol or with a reduced amount of this membrane additive, in particular the optimal formulation was that in which the cholesterol content was about 27wt% of total lipid amount: probably this value is a good compromise between the membrane stability and its deformation capacity, allowing a higher drug permeation across the skin. [Copyright &y& Elsevier]

Abstract: The synthesis and characterisation of new surfactants with peculiar physical–chemical properties are amongst the most promising and expanding issues in pharmacological colloid science. The most used vesicular carriers are liposomes prepared from a wide variety of natural and synthetic phospholipids, but several ionic and non-ionic amphiphiles have been used to form multilamellar and/or unilamellar vesicles. In the present study the synthesis of α,ω-trioxyethylene-bis(sodium 2-dodecyloxy-propylenesulfonate), an anionic Gemini surfactant, and its ability to form niosomes are elucidated. The compound forms vesicles with and without added cholesterol. The vesicular systems were characterized by size, shape and drug entrapment efficiency. The compounds to be incorporated are β-carotene and ferulic acid, as antioxidants, acetyl salicylic acid, as FANS, and the antineoplastic 5-flurouracil, widely used in dermatological disorders. The results of this study show that α,ω-trioxyethylene-bis(sodium 2-dodecyloxy-propylenesulfonate) can be used for the preparation of niosomes entrapping lypophilic, amphiphilic or hydrophilic substances. These niosomes may be promising candidates as percutaneous carriers for the aforementioned drugs. [Copyright &y& Elsevier]

Abstract: The role of nonionic vesicles on the rheological behavior of Pluronic F127 is investigated above the dilute regime and below the cloud point of the nonionic surfactant. F127 is a copolymer possessing sol–gel transition by heating attributed to a phase transition from micellar to cubic. The presence of surfactant vesicles is expected to enhance the compartmentalization of a variety of drugs, independently of their affinity to the solvent. Such entrapment would be suitable for controlled release of the drugs in different applications. We address here a mixed Pluronic–nonionic surfactant system with particular emphasis to the effects of the surfactant on the rheological properties of the Pluronics, and the correlation between these properties and drug release control. The results show that the rheological properties of the mixed system are mainly governed by the behavior of the polymer alone and that the mixed system can be useful to control the percutaneous permeation of a small drug, such as Diclofenac Sodium salt. [Copyright &y& Elsevier]