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Amphotericin B (AmB), a broad-spectrum polyene antibiotic in the clinic for more than fifty years, remains the gold standard in the treatment of life-threatening invasive fungal infections and visceral leishmaniasis. Due to its poor water solubility and membrane permeability, AmB is conventionally formulated with deoxycholate as a micellar suspension for intravenous administration, but severe infusion-related side effects and nephrotoxicity hamper its therapeutic potential. Lipid-based formulations, such as liposomal AmB, have been developed which significantly reduce the toxic side effects of the drug. However, their high cost and the need for parenteral administration limit their widespread use. Therefore, delivery systems that can retain or even enhance antimicrobial efficacy while simultaneously reducing AmB adverse events are an active area of research. Among those, lipid systems have been extensively investigated due to the high affinity of AmB for binding lipids. The development of a safe and cost-effective oral formulation able to improve drug accessibility would be a major breakthrough, and several lipid systems for the oral delivery of AmB are currently under development. This review summarizes recent advances in lipid-based systems for targeted delivery of AmB focusing on non-parenteral nanoparticulate formulations mainly investigated over the last five years and highlighting those that are currently in clinical trials.

[EN] A quality by design approach was used to investigate the influence of formulation composition and spray drying conditions on physicochemical properties of redispersable lipid based nanosystems loaded with Syzygium aromaticum essential oil. Four critical independent variables were studied: presence or absence of the liquid lipid oleic acid (0% - 1%), of the cationic surfactant CTAB (0% and 1%), inlet drying temperature (60 ºC -80 ºC), and ratio of the drying aids (ADJ) regarded to total formulation constituents weight (1:1 and 2:1). Resuls showed the production of spray dried redispersable lipid systems loaded with essential is feasible under very restrict conditions., The authors express their gratitute to São Paulo State Research Foundation (FAPESP) for the financial aid (Grants 2014/15905-1; 2011/10333-1), and to Brazilian National Council of Research and Development (CNPq) for the fellowship to the first author.

The aim of this work was to compare the antioxidant activity of the extract of flaxseed and its alkaline hydrolysate in two model systems: lipid autoxidation of triacylglycerols of sunflower oil (TGSO)—in a homogeneous lipid media and during β-carotene-linoleate emulsion system. In addition, pure lignans were tested. The material was defatted with hexane and then phenolic compounds were extracted using dioxane-ethanol (50:50, v/v) mixture. Carbohydrates were removed from the crude extract using an Amberlite XAD-16 column chromatography. The content of total phenolic compounds in the crude extract and after alkaline hydrolysis was determined using a Folin-Ciocalteu’s phenol reagent. Individual phenolic compounds were determined by nordihydroguaiaretic acid (RP-HPLC) method in gradient system. The alkaline hydrolysis increased the content of total phenolics in the extract approximately by 10%. In the extracts of flaxseed, phenolic compounds were present in the form of macromolecular complex. In the alkaline hydrolysate, secoisolariciresinol diglucoside (SDG) was found as the main phenolic compound. Small amounts of p-coumaric and ferulic acids were also determined. SDG and both extracts were not able to inhibit effectively lipid autoxidation. The kinetics of TGSO autoxidation at 80 °C in absence and in presence of the extract before hydrolysis (EBH) and after hydrolysis (EAH) was monitored and compared with known standard antioxidants. Ferulic acid (FA) and butylated hydroxyl toluene (BHT) showed much higher antioxidant efficiency and reactivity than that of both extracts. Secoisolariciresinol (SECO) showed a higher activity in both model systems than SDG. However, the activity of SECO was much lower than that of nordihydroquaiaretic acid (NDGA).

Lipid-based liquid crystalline systems are showing potential as stimuli-responsive nanomaterials, and NIR-responsive gold nanoparticles have been demonstrated to provide control of transitions in nonlamellar phases. In this study, we focus on a deeper understanding of the photothermal response of both lamellar and non-lamellar phases, and new systems formed by alternative lipid systems not previously reported, by linking the photothermal heating to the bulk thermal properties of the materials. Dynamic photothermal studies were performed using NIR laser irradiation and monitoring the structural response using time resolved small angle X-ray scattering for the bulk phases and hexosomes. In addition, cryoFESEM and cryoTEM were used to visualise and assess the effect of GNR incorporation into hexagonal phase nanostructures. The ability of the systems to respond to photothermal heating was correlated with the thermal phase behaviour and heat capacities of the different structures. Access to alternative phase transitions in these systems and understanding the likely photothermal response will facilitate different modes of application of these hybrid nanomaterials for on-demand drug delivery applications. Refereed/Peer-reviewed

This thesis was devoted to the development of innovative oral delivery systems for two different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S-100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan was extracted from corn cobs and characterized in terms of its physicochemical, rheological and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking polymerization and spray-drying and characterized for their morphology, mean size and distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release. MPs with suitable physical characteristics and satisfactory yields were prepared by both methods, although the spray-dried systems showed higher thermal stability. In general, spray-dried MPs would be preferable systems due to their thermal stability and absence of toxic agents used in their preparation. However, drug loading and release need to be optimized. In the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on medium-chain triglycerides were formulated as drug carriers and solubility enhancers for amphotericin B (AmB). Phase diagrams were constructed using surfactant blends with hydrophilic-lipophilic balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low polydispersity index. The incorporation of AmB was high and depended on the volume fraction of the disperse phase. These MEs did not reduce the viability of J774.A1 macrophage-like cells for concentrations up to 25 µg/mL of AmB. Therefore, O/W MEs based on propylene glycol esters of caprylic acid may be considered as suitable delivery systems for AmB., Cette thèse a été consacrée à la mise au point de deux systèmes d'administration destinés à la voie orale, pour deux molécules différentes.Dans la première partie, des microparticules (MPs) à base de xylane et d'Eudragit® S-100 ont été produites pour encapsuler l’acide 5-aminosalicylique et permettre son absorption au niveau du colon. Le xylane a été extrait à partir de rafles de maïs et caractérisé selon ses propriétés physico-chimiques, rhéologiques et toxicologiques. Par la suite, les MPs ont été préparées soit par réticulation interfaciale, soit par séchage par atomisation et caracterisés quant à leur morphologie, leur taille moyenne et leur distribution, leur stabilité thermique, leur cristallinité, leur efficacité et leur profil de libération du médicament in vitro. Des MPs de caractéristiques physiques appropriées avec des rendements satisfaisants ont été préparées par ces deux méthodes, bien que les systèmes séchés par pulvérisation aient montré une plus grande stabilité thermique. En général, ces derniers systèmes étaient plus prometteurs en raison de leur stabilité thermique et de l'absence d'agents réticulants toxiques. Toutefois, la méthodologie doit être optimiser afin d’améliorer le chargement de principe actif ainsi que sa libération.Dans la deuxième partie de cette thèse, des microémulsions huile-dans-l’eau (ME H/E) à base de triglycérides à chaîne moyenne ont été preparées afin de vectoriser et d’augmenter la solubilité de l'amphotéricine B (AmB). Des diagrammes de phases ont été construits en utilisant des mélanges de tensioactifs dont les valeurs de la balance hydrophile-lipophile variaient entre 9,7 et 14,4. Les MEs H/E sans et avec AmB étaient composées de gouttelettes sphériques non agrégées de diamètre moyen autour de 80 et 120 nm, respectivement, et avec une faible polydispersité. L'incorporation de l'AmB était élevée et dépendait de la fraction volumique de la phase dispersée. La viabilité des cellules J774.A1 n’était pas diminuée par l’exposition aux concentrations d’AmB encapsulée allant jusqu’à 25μg/mL. Par conséquent, les MEs H/E à base d’esters de propylèneglycol et d'acide caprylique peuvent être considéré comme des vecteurs adaptés pour l’AmB.

Conselho Nacional de Desenvolvimento Científico e Tecnológico This thesis was devoted to the development of innovative oral delivery systems for two different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S- 100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan was extracted from corn cobs and characterized in terms of its physicochemical, rheological and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking polymerization and spray-drying and characterized for their morphology, mean size and distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release. MPs with suitable physical characteristics and satisfactory yields were prepared by both methods, although the spray-dried systems showed higher thermal stability. In general, spraydried MPs would be preferable systems due to their thermal stability and absence of toxic agents used in their preparation. However, drug loading and release need to be optimized. In the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on mediumchain triglycerides were formulated as drug carriers and solubility enhancers for amphotericin B (AmB). Phase diagrams were constructed using surfactant blends with hydrophiliclipophilic balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low polydispersity index. The incorporation of AmB was high and depended on the volume fraction of the disperse phase. These MEs did not reduce the viability of J774.A1 macrophage-like cells for concentrations up to 25 μg/mL of AmB. Therefore, O/W MEs based on propylene glycol esters of caprylic acid may be considered as suitable delivery systems for AmB Esta tese teve como objetivo o desenvolvimento de novos sistemas de liberação para duas moléculas distintas. Na primeira parte, micropartículas à base de xilana e Eudragit® S-100 foram produzidas para encapsular ácido 5-aminosalicílico visando à liberação cólonespecífica. A xilana foi extraída de sabugos de milho e caracterizada quanto às suas propriedades físico-químicas, reológicas e toxicológicas. Em seguida, dois métodos de microencapsulação foram utilizados: reticulação interfacial polimérica e secagem por aspersão. Os sistemas produzidos foram caracterizados quanto à morfologia, tamanho médio e distribuição, estabilidade térmica, cristalinidade, taxa de encapsulação e liberação do fármaco in vitro. Foram obtidas micropartículas com adequadas características físicas e rendimentos satisfatórios através dos dois métodos, embora os sistemas aspergidos tenham apresentado maior estabilidade térmica e sejam considerados mais interessantes devido a sua maior estabilidade térmica e ausência de agentes tóxicos. No entanto, ajustes precisam ser feitos para melhorar a encapsulação e liberação do fármaco. Na segunda parte, microemulsões do tipo óleo em água (MEs O/A) com base em triglicerídeos de cadeia média (MCT) foram produzidas visando ao carreamento de anfotericina B (AmB) e aumento da sua solubilidade. Foram obtidas MEs O/A sem e com AmB com gotículas em torno de 80 e 120 nm, respectivamente, e índices de polidispersão de 0,25 e 0,31, respectivamente. A taxa de incorporação da AmB foi alta e dependente do volume da fase dispersa. A viabilidade celular não foi afetada até 25 μg/mL da AmB. Portanto, MEs O/A a partir de MCT podem ser promissores sistemas de liberação para AmB

Nano drug delivery system is the latest technology employed in various medicinal applications. This technology can be adapted to the conventional drug administration due to its site-specific targeting phenomena. The oral lipophilic drug administration has its drawbacks due to poor solubility and bioavailability. Lipid-based carrier systems are now widely popular due to improved efficiency, especially for lovastatin delivery. Lovastatin is an important drug which arrests the rate-limiting step of the cholesterol cascade. This drug has short half-lives, poor oral-administered bioavailability, poor solubility, and is rapidly metabolizable. Based on the composition, the drug delivery carriers are classified into solid lipid nanoparticles (SLNs), lipid emulsions (LEs), and nanostructured lipid carriers (NLCs). Among them, NLCs are a smarter generation of drug delivery carriers for lovastatin. The selection of various lipid systems and their formulation are discussed in this paper. Moreover, the characterization of these carrier systems to achieve the optimal characteristic features is discussed in a concise manner. � Seenivasan et al.

Far-from-equillibrium oscillating chemical reactions are among the simplest systems showing complex behaviors and emergent properties. This class of reactions is often employed to mimic and understand the mechanisms of a great variety of biological processes. In this context, pattern formation due to the coupling between reaction and transport phenomena represent an active and promising research area. In this paper, we present results coming from experiments where we tried to blend the structural properties of self-assembled matrixes (sodium dodecyl sulphate micelles and phospholipid bilayers) together with the evolutive peculiarities of the Belousov–Zhabotinsky reaction. A series of interesting dynamical behaviors, like spatio-temporal chaos, stationary patterns and segmented waves, were found in reaction–diffusion and reaction–diffusion–convection experiments.

There is considerable interest in constructing supramolecular hollow tube architectures based on amphiphilic molecules. This can be achieved by using relatively expensive synthetic lipids. Herein, we report on the facile preparation of self-assembled microtubes from a novel low-cost lipid mixture that does not require a previous chemical synthesis step and consists of the ethanolamine salt of 12-hydroxy-stearic acid in water. Tubes of more than 10 microm in length spontaneously form upon cooling from an isotropic solution. They exhibit inner and outer diameters of 400 and 600 nm, respectively, and their walls consist of concentric stacked bilayers of fatty acid salts, each separated by a layer of water.

This paper is an attempt to conceptualize pattern formation in self-organizing systems and, in particular, to understand how structures, oscillations or waves arise in a steady and homogenous environment, a phenomenon called symmetry breaking. The route followed to develop these ideas was to couple chemical oscillations produced by Belousov-Zhabotinsky reaction with confined reaction environments, the latter being an essential requirement for any process of Life. Special focus was placed on systems showing organic or lipidic compartments, which represent more reliable biomimetic matrices.