Short-wave and near infrared π-conjugated polymers hosted in a biocompatible microemulsion: a pioneering approach for photoacoustic contrast agents.

In the present study a biocompatible oil-in-water (O/W) microemulsion was developed carrying short-wave infrared (SWIR) π-conjugated polymers and possessing photoacoustic properties for the first time. SWIR and NIR absorbing conjugated polymers were accomplished to be dissolved in a Food & Drug Administration (FDA) approved natural oil limonene, to formulate an O/W microemulsion using biocompatible surfactants (Span80, Labrasol®). Detailed structural characterization in the absence and presence of the polymers was performed by means of dynamic light scattering (DLS), small-angle X-ray scattering (SAXS) and electron paramagnetic resonance (EPR) spectroscopy.

In Vitro Evaluation of Curcumin- and Quercetin-Loaded Nanoemulsions for Intranasal Administration: Effect of Surface Charge and Viscosity.

The nose-to-brain delivery of neuroprotective natural compounds is an appealing approach for the treatment of neurodegenerative diseases. Nanoemulsions containing curcumin (CUR) and quercetin (QU) were prepared by high-pressure homogenization and characterized physicochemically and structurally. A negative (CQ_NE-), a positive (CQ_NE+), and a gel (CQ_NEgel) formulation were developed.

Development and Study of Nanoemulsions and Nanoemulsion-Based Hydrogels for the Encapsulation of Lipophilic Compounds.

Biocompatible nanoemulsions and nanoemulsion-based hydrogels were formulated for the encapsulation and delivery of vitamin D and curcumin. The aforementioned systems were structurally studied applying dynamic light scattering (DLS), electron paramagnetic resonance (EPR) spectroscopy and viscometry. In vitro studies were conducted using Franz diffusion cells to investigate the release of the bioactive compounds from the nanocarriers.

Structural Study of (Hydroxypropyl)Methyl Cellulose Microemulsion-Based Gels Used for Biocompatible Encapsulations.

(Hydroxypropyl)methyl cellulose (HPMC) can be used to form gels integrating a w/o microemulsion. The formulation in which a microemulsion is mixed with a hydrated HPMC matrix has been successfully used as a carrier of biocompatible ingredients. However, little is known about the structure of these systems.

Development of a microemulsion for encapsulation and delivery of gallic acid. The role of chitosan.

A novel water-in-oil (W/O) microemulsion based on natural oils, namely extra virgin olive oil (EVOO) and sunflower oil (SO), in the presence of non-ionic surfactants was successfully formulated. The novel microemulsion was used as a carrier for gallic acid (GA) to assure its protection and efficacy upon nasal administration. The work presents evidence that this microemulsion can be used as a nasal formulation for the delivery of polar antioxidants, especially, after incorporation of chitosan (CH) in its aqueous phase.

Microstructure and biopharmaceutical performances of curcumin-loaded low-energy nanoemulsions containing eucalyptol and pinene: Terpenes' role overcome penetration enhancement effect?

The objective of this work was to develop low-energy nanoemulsions for enhanced dermal delivery of curcumin, using monoterpene compounds eucalyptol (EUC) and pinene (PIN) as chemical penetration enhancers. Spontaneous emulsification was the preparation method. All formulations contained 10% of the oil phase (medium-chain triglycerides (MCT), or their mixture with EUC or PIN).

Hydroxytyrosol encapsulated in biocompatible water-in-oil microemulsions: How the structure affects in vitro absorption.

Over the last years, the incorporation of natural antioxidants in food and pharmaceutical formulations has gained attention, delaying or preventing oxidation phenomena in the final products. In order to take full advantage of their properties, protection in special microenvironments is of great importance. The unique features of the natural phenolic compound hydroxytyrosol (HT) - including antioxidant, anti-inflammatory, antiproliferative and cardioprotective properties - have been studied to clarify its mechanism of action.

Formulation and Structural Study of a Biocompatible Water-in-Oil Microemulsion as an Appropriate Enzyme Carrier: The Model Case of Horseradish Peroxidase.

A novel biocompatible water-in-oil microemulsion was developed using nonionic surfactants and was investigated as a potential enzyme delivery system for pharmaceutical applications. The system was composed of isopropyl myristate/polysorbate 80 (Tween 80)/distilled monoglycerides/water/propylene glycol (PG), had a low total surfactant concentration (8.3% w/w), and was able to incorporate approximately 3% w/w aqueous phase containing horseradish peroxidase (HRP).

Tacrolimus loaded biocompatible lecithin-based microemulsions with improved skin penetration: Structure characterization and in vitro/in vivo performances.

In order to improve skin penetration of tacrolimus we aimed to develop potentially non-irritant, lecithin-based microemulsions containing ethanol, isopropanol and/or propylene glycol as cosurfactants, varying caprylic/capric triglycerides and propylene glycol monocaprylate as oil phase. The influence of excipients on the size of microemulsion region in pseudo-ternary phase diagrams and their ability to form different types of microemulsions was evaluated. The comprehensive physicochemical characterization of microemulsions and the evaluation of their structure was performed, while the localization of tacrolimus in microemulsions was further investigated using electron paramagnetic resonance spectroscopy.