Pickering nano-emulsions stabilized by Eudragit RL100 nanoparticles as oral drug delivery system for poorly soluble drugs.

The purpose of this study was to develop Pickering water-in-oil nano-emulsions only stabilized by Eudragit RL100 nanoparticles (NPs), in order to increase the nano-emulsion stability and create a barrier to improve the drug encapsulation and better control the drug release. The first part of this study was dedicated to investigating the nano-emulsion formulation by ultrasonication and understanding the interfacial behavior and role of NPs in the stabilization of the water/oil interface. The focus was on the surface coverage in the function of the formulation parameters (volume fractions) to disclose the extents and limitations of the process. The main physicochemical analysis of the Pickering nano-emulsions was performed by dynamic light scattering and transmission electron microscopy. On the other hand, the second experimental approach was dedicated to understanding the interfacial behavior of the Eudragit RL100 NPs toward a model water/oil interface, using a dynamic tensiometer with axisymmetric drop shape analysis. The study investigated the NPs' adsorption, as well as their rheological behavior. The aim of this part was to reveal the main phenomena that govern the interactions between NPs and the interface in order to understand the origin of Pickering nano-emulsions' stability. The last part of the study was concerned with the stability and in vitro release of a model encapsulated drug (ketoprofen) in a gastric and simulated intestinal environment. The results showed that Pickering nano-emulsions significantly improved the resistance to gastric pH, inducing a significantly slower drug release compared to classical nano-emulsions' stabilized surfactants. These Pickering nano-emulsions appear as a promising technology to modify the delivery of a therapeutic agent, in the function of the pH, and can be, for instance, applied to the oral drug delivery of poorly soluble drugs.

Pickering nano-emulsions stabilized by solid lipid nanoparticles as a temperature sensitive drug delivery system.

The development of biomaterials with low environmental impact has seen increased interest in recent years. In this field, lipid nanoparticles have found a privileged place in research and industry. The purpose of this study was to develop Pickering O/W nano-emulsions only stabilized by solid lipid nanoparticles (SLNs), as a new generation of safe, non-toxic, biocompatible, and temperature-sensitive lipid nano-carriers. The first part is dedicated to understanding the interfacial behavior of SLNs and their related stabilization mechanisms onto nano-emulsions formulated by ultrasonication. Investigations were focused on the surface coverage as a function of the SLN size and volume fraction of dispersed oil, in order to prove that the droplet stabilization is effectively performed by the nanoparticles, and to disclose the limitations of this formulation. Characterization is performed by dynamic light scattering and transmission electron microscopy. The second part of the study investigated SLN adsorption on a model oil/water interface (surface tension and rheology) through an axisymmetrical drop shape analysis (drop tensiometer), following the interfacial tension and the rheological behavior. The objective of this part is to characterize the phenomenon governing the droplet/interface interactions, and disclose the rheological behavior of the interfacial SLN monolayer. The effect of temperature was also investigated, proving a real destabilization of the nano-suspension when the sample is heated above a temperature threshold, impacting on the integrity of the SLNs, which partially melt, and strongly enhancing the release of a model drug (ketoprofen) encapsulated in the nano-emulsion oil core. To conclude, Pickering nano-emulsions only stabilized by SLNs appear to be a very efficient innovative drug nano-carrier, opening new doors as a potential temperature-sensitive drug delivery system.

Correction: Pickering nano-emulsions stabilized by solid lipid nanoparticles as a temperature sensitive drug delivery system.

Correction for 'Pickering nano-emulsions stabilized by solid lipid nanoparticles as a temperature sensitive drug delivery system' by Sidy Mouhamed Dieng et al., Soft Matter, 2019, DOI: 10.1039/c9sm01283d.

[Development of Ethylcellulose/Eudragit matrix for controlled and continuous release of insulin]. / Developpement d'une matrice ethylcellulose/eudragit pour la liberation controlee et continue de l'insuline.

PURPOSE: Diabetes Type I is a chronic disease requiring insulin repeated injections by parenteral during a lifetime. This method of administration as well as traumatic can be a problem for adherence of patients to treatment. In order to overcome these difficulties, we considered the development of therapeutic transdermal drug delivery (TTDD) of insulin. MATERIAL AND METHOD: As active ingredient we used anhydrous human insulin Actarapid HM from Novo Nordisk laboratory, the excipients are ethyl cellulose, Eudragit RS 100 and butylphtalate. We developed two matrix Ethylcellulose/Eudragit in reports 1 and 2, in which are incorporated different proportions of insulin. RESULTS: The study of the release of insulin in phosphate buffer at pH 7.4, showed a continuous release profiles strongly depending on Ethylcellulose/Eudragit report and the initial charge of insulin. CONCLUSION: This study shows that the matrix Ethylcellulose/Eudragit lends itself to the development of a controlled release of insulin. This allows us to continue this work by combining this matrix with other elements for achieving an insulin TTDD.

[The excipient properties of shea butter compared with vaseline and lanolin]. / Les propriétés d'excipient du beurre de Karité comparées à celles de la vaseline et de la lanoline.

A shea butter ointment containing 3% aureomycin (clortetracyclin hydrocloride) was prepared and some of its macroscopic and microscopic characteristics were evaluated. Then, the release of the active ingredient was compared by UV spectrophotometry with those obtained when excipients such as petroleum jelly and lanoline were used. Results had shown that the shea butter ointment had satisfactory characteristics. In the other hand, it was found that shea butter released the aureomycin easily and at a faster rate than the other excipients.