Job title:
Stabilization of Pickering emulsions by association of biodegradable and biocompatible polymer particles
Company
Job description
Job Information Organisation/CompanyLaboratoire d’Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), Lyon Research FieldChemistry Researcher ProfileRecognised Researcher (R2)Leading Researcher (R4)First Stage Researcher (R1)Established Researcher (R3) CountryFrance Application Deadline14 May 2024 – 22:00 (UTC) Type of ContractTemporary Job StatusFull-time Offer Starting Date1 Oct 2024 Is the job funded through the EU Research Framework Programme?Not funded by an EU programme Is the Job related to staff position within a Research Infrastructure?NoOffer DescriptionAn emulsion is a mixture of two immiscible or partially miscible liquids. One of the two phases is dispersed in the other in the form of fine droplets using mechanical energy. The resulting system is usually stabilized by the addition of one or more surfactants. Emulsion-based formulations are widely used in industry, particularly for pharmaceutical and cosmetic applications. However, the presence of surfactants in these formulations can cause undesirable effects due to their irritant nature and haemolytic behaviour.In the last decade, another type of emulsion, made without surfactants, has come into increasing use: Pickering emulsions. Pickering emulsions are stabilized by solid particles. Depending on the wettability and size of the particles used, oil/water or water/oil emulsions can be prepared with average drop sizes ranging from a few micrometers to a few millimeters. The absence of surfactants and the high resistance to coalescence of these emulsions make them particularly interesting for pharmaceutical and cosmetic applications [1].LAGEPP is recognized for its research activities in the development of these emulsions and their applications, particularly for the cutaneous administration of pharmaceutical or cosmetic active ingredients [2-6]. Very recently, we studied Pickering emulsions stabilized with a mixture of two types of biocompatible PMMA-based microparticles with different surface charges (neutral/anionic, neutral/cationic and anionic/cationic). We have shown the influence of particle adsorption rate on the size, coverage, morphology and stability of emulsion droplets [6]. We have also demonstrated the benefits of combining these microparticles to co-encapsulate two different active ingredients (one in the oil phase and the other in the particles) and to deliver them topically. Topical drug administration is particularly interesting. For dermatological pathologies, the active ingredient is applied locally to the site of the disease, thus optimizing its dermatological efficacy. In addition, its local diffusion limits the occurrence of undesirable effects due to action on other skin targets. The topical route can also be used for systemic delivery: this avoids the first hepatic passage of metabolization of the active ingredient and therefore improves its bioavailability [7].To continue this project, we want to formulate neutral, anionic and cationic biodegradable and biocompatible polymer nanoparticles and microparticles. Once again, two types of polymer particles will be used to stabilize the emulsion and to encapsulate two different active ingredients. The aim is to examine the differences in behaviour between emulsions prepared using nanoparticles and those obtained using microparticles, and to propose a biodegradable and biocompatible vector for the simultaneous and controlled topical delivery of two active ingredients.Detailed description of the project:To complete this project, three types of biodegradable and biocompatible polymer nanoparticles and microparticles (neutral, anionic and cationic) will first have to be developed. The size and surface charges of these objects will have to be controlled. Secondly, and following on from the work carried out at LAGEPP [6], the approach will involve using microparticles alone or in a binary mixture to stabilize emulsions. Fluorescent microparticles will be prepared to be observed by confocal fluorescence microscopy. Adsorption at the interfaces of the microparticles will be related to the stability of the emulsions. The results will be compared with those previously obtained with biocompatible microparticles (Figure 1). The characteristics (size, stability) of emulsions stabilized with nanoparticles (alone or in a binary mixture) will then be studied in order to highlight differences in behaviour compared with the use of microparticles as stabilizers.Another fundamental aspect is the experimental study of the transfer of active ingredients within the emulsion. In a final step, we will use two active ingredients which will be co-encapsulated in the emulsion (the stabilizing systems used will be defined according to the results obtained previously). The aim will be to understand the various mass transfers from the core of the microparticles to that of the emulsion droplets or into the continuous phase. These transfer phenomena would modify the location of the active ingredients within the emulsion and could therefore have an impact on the bioavailability of the active ingredient. The aim of this stage of the study is to see whether it would be possible to deliver in a differentiated way several active ingredients with different biological targets.Finally, the optimal emulsions will be tested for cutaneous administration of two active ingredients. Their penetration will be determined experimentally in vitro in metabolically inactive pig skin explants using Franz diffusion cells. Penetration will be monitored in the different layers of the skin: the epidermis, whose superficial layer is the stratum corneum, the dermis and the hypodermis. The aim is to validate the possibility of targeting a specific skin layer by the active ingredients.This study will provide knowledge of the stabilization mechanisms of Pickering emulsions and develop formulations of interest capable of delivering several active ingredients in a targeted manner.[1] Chevalier Y., Bolzinger M.A., Emulsions stabilized with solid nanoparticles: Pickering emulsions, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 439, 23-34, 2013[2] ., Bolzinger M.A., Valour J.P., Mouaziz H., Pelletier J., Chevalier Y., 368 (1-2), 7-15, 2009[3] ., Bolzinger M.A., Pelletier J., Valour J.P., Chevalier Y., Topical delivery of lipophilic drugs from o/w Pickering emulsions, I 371 (1-2), 56-63, 2009[4] Laredj-Bourezg F., Chevalier Y., Bolzinger M.A., 21 (9), 2012[5] Laredj-Bourezg F., Bolzinger M.A., Pelletier J., Chevalier Y., 531 (1), 134-142, 2017[6] Benyaya M., Bolzinger M.A., Chevalier Y., Ensenat S., Bordes C., Pickering emulsions stabilized with differently charged particles, 19, 4780-4793, 2023[7] Lalloz-Faivre A., Thèse de doctorat, Administration de substances actives dans la peau : rôle de la composition hydrophile de nanoparticules polymériques, Université de Lyon, 2019Funding category: Contrat doctoral
Concours ED Chimie Lyon
PHD title: Chimie, Formulation
PHD Country: FranceRequirementsSpecific RequirementsLe/la candidat.e est de niveau Master 2 en Chimie, Physico-Chimie et/ou Formulation. Il/elle a de l’expérience en recherche dans un laboratoire académique ou industriel en contexte Chimie/Formulation. Il/elle a des connaissances approfondies en physico-chimie et maîtrise l’anglais.The candidate has a Master’s degree in Chemistry, Physical Chemistry and/or Formulation. He/she will have research experience in an academic or industrial laboratory in a chemistry/formulation context. He/she will have in-depth knowledge of physical chemistry and be fluent in English.Additional InformationWork Location(s)Number of offers available 1 Company/Institute Laboratoire d’Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), Lyon Country France City VilleurbanneWhere to apply WebsiteSTATUS: EXPIRED
Expected salary
Location
Pickering, North Yorkshire
Job date
Mon, 29 Apr 2024 04:54:44 GMT
To help us track our recruitment effort, please indicate in your email/cover letter where (un-jobs.net) you saw this job posting.
