Pickering emulsion stabilized by cashew gum- poly-l-lactide copolymer nanoparticles: Synthesis, characterization and amphotericin B encapsulation

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2018-04, Vol.164, p.201-209
• Main Authors: Richter, A.R., Feitosa, J.P.A., Paula, H.C.B., Goycoolea, F.M., de Paula, R.C.M.
• Format: Article
• Language: English
• Subjects: Amphotericin B; Cashew gum; Copolymer; Nanoparticles; Pickering emulsion; Poly-l-lactide
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2018.01.023

[Display omitted] •Pickering emulsion (PE) systems based on cashew gum/PLAP copolymers were produced.•PE (CGPLAP 1:1) show monomodal distributions at different CGPLAP concentration.•Lower size and PDI and the best stability over time were observed for PE with CGPLAP.•AmB was associated in PE in less aggregated form than commercial formulations. In this work, we provide proof-of-concept of formation, physical characteristics and potential use as a drug delivery formulation of Pickering emulsions (PE) obtained by a novel method that combines nanoprecipitation with subsequent spontaneous emulsification process. To this end, pre-formed ultra-small (d.∼10 nm) nanoprecipitated nanoparticles of hydrophobic derivatives of cashew tree gum grafted with polylactide (CGPLAP), were conceived to stabilize Pickering emulsions obtained by spontaneous emulsification. These were also loaded with Amphotericin B (AmB), a drug of low oral bioavailability used in the therapy of neglected diseases such as leishmaniasis. The graft reaction was performed in two CG/PLA molar ratio conditions (1:1 and 1:10). Emulsions were prepared by adding the organic phase (Miglyol 812®) in the aqueous phase (nanoprecipitated CGPLAP), resulting the immediate emulsion formation. The isolation by centrifugation does not destabilize or separate the nanoparticles from oil droplets of the PE emulsion. Emulsions with CGPLAP 1:1 presented unimodal distributions at different CGPLA concentration, lower values in size and PDI and the best stability over time. The AmB was incorporated in the emulsions with a process efficiency of 21–47%, as determined by UV–vis. AmB in CGPLAP emulsions is in less aggregated state than observed in commercial AmB formulation.