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Pickering emulsions are systems without surfactants, stabilized by solid particles. These emulsions are experiencing a renewed interest, on the one hand, because it is preferable to limit the use of synthetic surfactants for toxicological and environmental reasons and, on the other hand, the need to make new formulations in order to control the drug release patterns by encapsulation or controlled release. Thus, we were interested in the formulation and evaluation of W/O Pickering emulsions stabilized by particles of magnesium oxide with paracetamol in the internal phase and griseofulvin in the external phase. The Bancroft rule served as a model for the formulation. The emulsification was carried out by progressively adding an aqueous phase dispersed in an oil-dispersing phase using a turbo rotor stator mixer. The stability of these emulsions was studied using several parameters (droplet size, pH, viscosity, conductivity ...) and the qualitative and quantitative analysis of the active ingredients by UV-visible spectrophotometry. The results obtained showed that the dye test and the conductivity measurement confirmed the W/O nature of these emulsions. Some parameters such as droplet size, pH and viscosity were strongly influenced by the amounts of magnesium oxide particles and the two active ingredients used. The qualitative and quantitative analysis of the active ingredients confirmed the presence of griseofulvin in the oil phase and paracetamol in the aqueous phase. Thus, we have succeeded in developing a stable W/O Pickering emulsion with magnesium oxide particles. In addition, we were able to incorporate paracetamol into the dispersed phase and griseofulvin into the How to cite this paper:

Pickering emulsions are systems without surfactants, stabilized by solid particles. These emulsions are experiencing a renewed interest, on the one hand, because it is preferable to limit the use of synthetic surfactants for toxicological and environmental reasons and, on the other hand, the need to make new formulations in order to control the drug release patterns by encapsulation or controlled release. Thus, we were interested in the formulation and evaluation of W / O Pickering emulsions stabilized by particles of magnesium oxide with tramadol hydrochloride in the internal phase. The Bancroft rule served as a model for the formulation. The emulsification was carried out by progressively adding an aqueous phase dispersed in an oil-dispersing phase using a turbo rotor stator mixer. The stability of these emulsions was studied using several parameters (droplet size, pH, viscosity, conductivity...) and the qualitative and quantitative analysis of the active ingredient by UV-visible spectrophotometry. The results obtained showed that the dye test and the conductivity measurement confirmed the W / O nature of these emulsions. Some parameters such as droplet size, pH and viscosity were strongly influenced by the amounts of Magnesium oxide particles and the active ingredient. The qualitative and quantitative analysis of the active ingredient confirmed the presence of tramadol in the internal aqueous phase. Thus, we have succeeded in developing a stable W / O Pickering emulsion with magnesium oxide particles. In addition, we were able to encapsulate tramadol in the dispersed aqueous phase.

Nanomedicine has been a booming industry with the development of nanovectors to encapsulate water-soluble or amphiphilic molecules for drug delivery. As the new therapeutic agents synthesized are increasingly lipophilic, the development of new nanoparticulate vectors allowing their transport and targeting is now a major challenge. These particles are lipid nanoparticles, a few hundred nanometers in diameter, stabilized by a layer of surfactants composed of castor oil and stealth agents. Solid lipid nanoparticles based on shea butter, stabilized by cremophor® ELP, encapsulating griseofulvin, were formulated by the temperature phase inversion method. The shea butter nanoparticles thus obtained were the subject of characterization relating to: determination of the morphology, size, polydispersity index, pH and zeta potential. The results confirm the stability of our preparations. The anti-inflammatory activity of shea butter being known, the tests were carried out on mice. The inflammation was induced by a solution of croton oil acetone. There is a very big improvement in anti-inflammatory activity. This is due to better penetration of the preparation through the different layers of the skin. Griseofulvin release studies have been carried out on our various preparations. Systems designed as reservoirs of active ingredients and intended for a priori controlled release obey kinetics of the order of one-half (½) corresponding to a proportionality between the quantity released and the square root of time. Shea butter in nanoparticulate forms has thus enabled us to considerably prolong the release of griseofulvin. Keywords: Nanoparticles; Shea Butter; Inflammation; Griseofulvin.

Multiple emulsions are of great therapeutic interest especially in the administration of medicines which can be inactivated by digestive enzymes; moreover the researches of formulation not being often easy, a control of the different phases physicochemical parameters would be of great interest in rapid formulations and at low cost. When formulating emulsions, the preliminary tests, also known as formulation tests, constitute a step which can be long and expensive because of the quantity of reagents that can be used. A rigorous methodology could thus be of great interest, which is at the aim of our study which consists of evaluating the physico-chemical parameters of different phases used to make thus multiple emulsions. In our study, physico-chemical parameters such as conductivity, pH, density, viscosity, and surface tension have been studied by direct measurement using equipment and also by means of suitable mounting. The results showed that the pH and the surface tension have an important role in the prediction of the stability of emulsions, these latter must be of the same order of magnitude. For all phases conductivity does not have too much interest apart from helping to determine the type of the emulsion.