Study and optimization of freeze-drying cycles of a model probiotic strain

[EN] This work is based on the experimental study of the freeze-drying process to understand the impact of numerous factors on the survival rates of a model probiotic strain of Lactobacillus casei type. With the aim to find out if cell density in the matrix and survival rates are linked, we have studied the location of the cells after freeze drying inside a porous matrix composed of a lactose basis with a polymer, the polyvinylpyrrolidone (PVP) in various amounts. The best survival rate were obtained at slow freezing rate for a formulation containing 5% (m/V) of lactose and 5% (m/V) of PVP.Verlhac, P.; Vessot-Crastes, S.; Degobert, G.; Cogné, C.; Andrieu, J.; Beney, L.; Gervais, P. (2018). Study and optimization of freeze-drying cycles of a model probiotic strain. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 635-642. https://doi.org/10.4995/IDS2018.2018.7400OCS63564

How to encourage young people to take up a career in aerosol industry ?

International audienc

Lyophilisation of nanocapsule suspensions with polycaprolactone membrane

International audienc

Freeze drying nanoparticulate systems

International audienceParticulate systems are various size, shapes and morphologies (nano- microparticles, liposomes, core-shell..). The development of these particulate systems is becoming increasingly important as a result of diverse industrial applications. The poor stability in aqueous medium of these systems constitutes a real obstacle to their commercialization. In this context, freeze drying is considered as the most convenient process to improve their long term stability. In this presentation, one will discuss the most important parameters that influence the success of freeze-drying of particulate systems and provides an overview of freeze-drying process and formulation strategies with a focus on the impact of formulation and process on particle stability

How to encourage young people to take up a career in aerosol industry ?

International audienc

Dispositifs d'administration pulmonaire

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Loading and in vitro release of salbutamol from degradable cross-linked starch microspheres intended for pulmonary administration

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La lyophilisation (revalidation périodique du maintien de la stérilité d'un lyophilisateur dans un service de mise sous forme pharmaceutique)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Freeze drying of Poly(ε-caprolactone) nanocapsules stabilized by Poly(vinyl-alcohol): Formulation and process optimization

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A pilot study of freeze drying of poly(epsilon-caprolactone) nanocapsules stabilized by poly(vinyl alcohol): Formulation and process optimization

International audienceA common limitation of using polymeric nanoparticles in aqueous suspension is due to their poor chemical and physical stability when conserved for a long time. Therefore, freeze drying of these colloidal systems is an alternative method to achieve long-term stability. Nanocapsules have thin and fragile shell structure, which may not resist to the stress of such process. The aim of this study is to investigate the formulation and process parameters in order to ensure the stability of polycaprolactone nanocapsules (PCL NC) by freeze drying.In this paper, we studied the freeze drying of PCL NC prepared by the emulsion–diffusion method and stabilized by poly(vinyl alcohol) (PVA). Different parameters have been tested throughout the freeze–thawing study including PVA and PCL concentration, cooling rate, cryoprotectant concentrations, nature of encapsulated oil and NC purification. On the other hand, nanocapsules have been freeze dried both before and after purification. Freeze dried purified PCL NC were characterized by particle size measurement, collapse temperature, determination, scanning electron microscope observation, environmental scanning electron microscope imaging and residual humidity quantification. Finally, the effect of annealing on the NC stability and the sublimation rate has been well explored.The results suggest that PCL NC could be freeze dried without a cryoprotectant if the concentration of PVA stabilizer is sufficient (5%), while for the purified NC the addition of 5% of cryoprotectant seems to be necessary to ensure the stability of NC. The type of cryoprotectants had practically negligible effects on the size and the rehydration of freeze dried nanocapsules. The annealing process could accelerate the sublimation with the conservation of nanocapsules size