Particle size and zeta potential

Matec (www.matec.com) Acoustisizer Electro-acoustic spectroscopy Particle sizing and zeta potential No Yes... 

Drug-loaded nanoparticles were also evaluated for their safety and efficacy. Paclitaxel-encapsulated 6-O-CAPRO-p-CD nanospheres and nanocapsules were evaluated for their physical stability in a one-month period in aqueous dispersion form with repeated particle size and zeta potential measurements and AFM imaging to evaluate recrystallization in aqueous medium. Paclitaxel-loaded amphiphilic CD nanoparticles were found to be physically stable for a period of one month whereas recrystallization occurs within minutes when diluted for intravenous (IV) infusion [85], Finally, paclitaxel-loaded amphiphilic nanoparticles were demonstrated to show similar anticancer efficacy against MCF-7 cells when compared to paclitaxel solution in a cremophor vehicle [85],... 

The original Acoustosizer used a single frequency whereas a later development has a range of 13 frequencies between 0.3 and 13 MHz. This allows the measurement of the dynamic mobility spectrum and the determination of the zeta potential and particle size. In order to invert the mobility spectrum into a size distribution a log-normal distribution of particle size is assumed. A comparison with photon correlation spectroscopy for determining particle size and laser Doppler anemometry for particle charge eonfirmed the results using ACS [266]. These and additional sedimentation measurements confirmed that changes in particle size and zeta potential due to dilution effects are likely to occur in aqueous and non-stabilized systems. 

Particle sizes of diazepam-loaded SLN showed similar changes after sterilization as did drug-free systems. Steam sterilization (121 °C, 20 min) did not cause changes in particle size and zeta potential of azidothymidine palmitate-loaded SLN (trilaurin, phospholipid stabilized) [47],... 

RW O Brien, DW Cannon, WN Rowlands. Electroacoustic determination of particle size and zeta potential. J Coll Interf Sci 173 406-418, 1995. 

Particle size and zeta potential Photon correlation spectroscopy (PCS) and laser diffraction (LD) are the most powerful techniques for routine measurements of particle size... 

Figure 6.27 Changes of average particle size and zeta potential during addition of...

Zhao et al. [45] investigated dual dehvery of the anticancer drug doxorubicin and gene (DNA) in modified alginate-based nanoparticles. The particle size and zeta potential of... 

A. Dukhin, S. Parlia, D. Klank, M. Lesti, Particle sizing and zeta potential of silica Koestrosol (basis for certified reference material ERM-FDIOO for nanoparticles) by acoustics and electroacoustics. Part. Part. Syst. Charact. 27(5-6), 165-171 (2012). doi 10.1002/ppsc. 201100038... 

Effect of the Adsorption of PEG-PLACopolymers and of Poloxamine 908 on Polystyrene and PLGA Nanospheres on the Particle Size and Zeta Potential"... 

Particularly by preparation of SLN from warm microemulsions, emulsifiers are used in high excess and are normally removed by an adequate purification process. Heydenreich et al. investigated different purification processes (ultrafiltration, ultracentrifugation, and dialysis) and studied the cytotoxicity of the purified cationic SLN dispersions beside particle size and zeta potential. The removal of excess polysorbate decreased the toxicity about 10-fold and dialysis was found to be the preferred method to remove the excess of polysorbate whereas particularly ultrafiltration was not as efficient. 

Electroacoustics The particles move in an appUed field if the particle density differs from that of the liquid, the motion generates an alternating acoustic wave. The electrokinetic sonic amphtude is measured as a fimction of frequency. From the electroacoustic spectrum, both the particle size and zeta potential can be determined. High suspension densities are possible with this method. 

Particle size and zeta potential measurements The particle size and particle size distribution were determined by dynamic light scattering (DLS) using Zetasizer 3000HSA instrument (Malvern, UK) at a fixed angle of 90° and laser wavelength of... 

O Brien, R. W., Cannon, D. W., Rowlands, W., Electroacoustic Determination of Particle Size and Zeta Potential, / Colloid Interface Sci 1995, 173,406-418. 

The Electrokinetic Sonic Amplitude (ESA) effect in this context refers to the generation of ultrasound by the application of an alternating electric field to a colloid. Previous reviews on the ESA have mainly focused on the determination of particle size and zeta potential from the ESA. While this is certainly a very important application of the ESA phenomenon, there is more information in the ESA spectmm than just particle size and zeta. It can be used, for instance, to determine the thickness of adsorbed polymer layers or the surface conductance under the shear plane. It is these other applications that will be our main interest here. To begin we will give an alternative explanation for the ESA phenomenon, one that allows a deeper understanding of the underlying physics. 

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