TY  - JOUR
A1  - Brunacci, Nadia
A1  - Wischke, Christian
A1  - Naolou, Toufik
A1  - Neffe, Axel T.
A1  - Lendlein, Andreas
T1  - Influence of surfactants on depsipeptide submicron particle formation
JF  - European Journal of Pharmaceutics and Biopharmaceutics
N2  - Surfactants are required for the formation and stabilization of hydrophobic polymeric particles in aqueous environment. In order to form submicron particles of varying sizes from oligo[3-(S)-sec-butylmorpholine-2,5-dione]diols ((OBMD)-diol), different surfactants were investigated. As new surfactants, four-armed star-shaped oligo(ethylene glycol)s of molecular weights of 5-20 kDa functionalized with desamino-tyrosine (sOEG-DAT) resulted in smaller particles with lower PDI than with desaminotyrosyl tyrosine (sOEG-DATT) in an emulsion/solvent evaporation method. In a second set of experiments, sOEG-DAT of M-n= 10 kDa was compared with the commonly employed emulsifiers polyvinylalcohol (PVA), polyoxyethylene (20) sorbitan monolaurate (Tween 20), and D-alpha-tocopherol polyethylene glycol succinate (VIT E-TPGS) for OBMD particle preparation. sOEG-DAT allowed to systematically change sizes in a range of 300 up to 900 nm with narrow polydispersity, while in the other cases, a lower size range (250-400 nm, PVA; 300 nm, Tween 20) or no effective particle formation was observed. The ability of tailoring particle size in a broad range makes sOEG-DAT of particular interest for the formation of oligodepsipeptide particles, which can further be investigated as drug carriers for controlled delivery. (C) 2016 Elsevier B.V. All rights reserved.
KW  - Depsipeptide
KW  - Particle size
KW  - Surfactants
KW  - Submicron particles
Y1  - 2017
U6  - https://doi.org/10.1016/j.ejpb.2016.11.011
SN  - 0939-6411
SN  - 1873-3441
VL  - 116
SP  - 61
EP  - 65
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Lopez, Carlos G.
A1  - Manova, Anna
A1  - Hoppe, Corinna
A1  - Dreja, Michael
A1  - Schmiedel, Peter
A1  - Job, Mareile
A1  - Richtering, Walter
A1  - Böker, Alexander
A1  - Tsarkova, Larisa A.
T1  - Combined UV-Vis-absorbance and reflectance spectroscopy study of dye transfer kinetics in aqueous mixtures of surfactants
JF  - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects
N2  - We report an analytical approach to study the competitive processes of solubilisation in micelles and of adsorption onto hydrophobic surfaces of poorly soluble hydrophobic dyes. The method is demonstrated on model systems containing two sources of Disperse Red 60: a bulk powder and a donor red textile, with molecularly dissolved dye stabilised in an aqueous environment by mixed micelles of anionic and non-ionic surfactants. The process of dye transfer between a donor textile (red polyester), surfactant micelles and an acceptor textile (white polyamide) was quantified by a combination of colorimetric analyses. UV-Vis absorbance was used to follow the extraction of the dye and to evaluate the solubilisation capacity of the micellar solution. A calibration curve for textile reflectance versus the adsorbed dye was generated to quantify the mass of dye transferred onto the acceptor textile. A combination of both techniques allowed us to compare the amount of dye desorbed from the donor textile and adsorbed onto the acceptor textile as a function of time for systems undergoing exhaustion-solubilisation mechanisms and only solubilisation mechanism. Up to similar or equal to 10 min of the washing process, the released dye is predominantly solubilised in surfactant micelles. At later times, the adsorption of the dye on the hydrophobic surface is energetically favoured. The shift of the desorption equilibrium in the presence of the acceptor textile results in similar or equal to 30% increase in the release of the dye. The reported methodology provides direct comparative analysis between the solubilisation capacity of amphiphilic stabilisers and the tendency of the dye to adsorb on solid substrates, important for designing novel concepts of disperse dye solubilisation and dye transfer inhibition during textile washing.
KW  - Dye transfer
KW  - Disperse dyes
KW  - Surfactants
KW  - Detergent
KW  - Colorimetric analysis
KW  - Washing fastness
Y1  - 2018
U6  - https://doi.org/10.1016/j.colsurfa.2018.04.024
SN  - 0927-7757
SN  - 1873-4359
VL  - 550
SP  - 74
EP  - 81
PB  - Elsevier
CY  - Amsterdam
ER  -