Process conditions for preparing well-defined nano- and microparticles as delivery systems of alkyl gallates--颗粒学报PARTICUOLOGY

Chebil, A., Funfschilling, D., Six, J.-L., Nouvel, C., Durand, A., & Léonard, M. (2019). Process conditions for preparing well-defined nano- and microparticles as delivery systems of alkyl gallates. Particuology, 44, 105-116. https://doi.org/10.1016/j.partic.2018.07.003

Process conditions for preparing well-defined nano- and microparticles as delivery systems of alkyl gallates

Asma Chebil ^a, Denis Funfschilling ^{b 1}, Jean-Luc Six ^a, Cécile Nouvel ^{a 2}, Alain Durand ^a, Michèle Léonard ^a *

a Université de Lorraine, CNRS, LCPM, F-54000 Nancy, France
b Université de Lorraine, CNRS, LRGP, F-54000 Nancy, France

10.1016/j.partic.2018.07.003

Volume 44, June 2019, Pages 105-116

Received 31 March 2018, Revised 17 June 2018, Accepted 1 July 2018, Available online 21 December 2018, Version of Record 30 April 2019.

E-mail: michele.leonard@univ-lorraine.fr

Highlights

• Suspensions of dextran-covered poly(d,l-lactide) particles were prepared.

• Emulsion/solvent evaporation (diffusion) process was used with dextran derivatives.

• Varying emulsification conditions led to a wide range of particle diameters.

• Encapsulation of alkyl gallates in each particle type was performed and evaluated.

• Release kinetics were monitored and compared according to the class of particles

Abstract

Dextran-covered poly(d,l-lactide) (PLA) nano- and microparticles were prepared using an emulsion/solvent evaporation (or diffusion) process for the encapsulation of alkyl gallates (AGs). In the first step, a solution of PLA and AG in ethyl acetate was emulsified to give an aqueous phase containing a hydrophobically modified dextran, which acted as a stabilizer. The second step involved solvent evaporation or diffusion. The emulsification conditions were varied, which allowed for the preparation of nano- and microparticle suspensions covering a wide range of surface-average particle diameters from 0.1 μm (sonication) to 500 μm (stirring with a magnetic bar), with narrow and reproducible size distributions. Continuous microfluidic emulsification in a flow-focusing system led to well-defined microparticles, in the 10–50 μm range. Particles loaded with octyl gallate (OG) and nonyl gallate (NG) were obtained using the three processes, and we showed that the encapsulation efficiency of OG and NG varied significantly depending on the emulsification process. The effect of particle size on the mechanism of in vitro release of encapsulated AGs was investigated. The kinetics of release were controlled either by Fickian diffusion within the solid core or swelling and hydrolytic degradation of the PLA matrix, depending on the pH of the external medium.

Graphical abstract

Keywords

Emulsion/solvent evaporation; DextranPoly(d,l-lactide); Encapsulation; Release; Alkyl gallate

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