Size-Selective Fractionation of Nanoparticles

Saunders, S.R. and Roberts, C.B. (2009) Size-selective fractionation of nanoparticles at an application scale using C02 gas-expanded liquids. 

Anand, M., McLeod, M.C., Bell, P.W. and Roberts, C.B. (2005) Tunable solvation effects on the size-selective fractionation of metal nanoparticles in C02 gas-expanded solvents. Journal of Physical Chemistry B, 109 (48), 22852-22859. 

Figure 2.5 Schematic diagram of an apparatus capable of size-selectively fractionating large quantities of nanoparticles. Reproduced from [18] 2010 IOP Publishing.

Anand, M., You, S.S., Hurst, KM., Saunders, S.R., Kitchens, C.L., Ashurst, W.R. and Roberts, C.B. (2008) Thermodynamic analysis of nanoparticle size selective fractionation using gas-expanded liquids. Industrial and Engineering Chemistry Research, 47 (3), 553-559. 

An apparatus to fractionate size-selectively small quantities (sub-milligram quantities of nanoparticle material) is presented in Figure 2.4b [19]. This apparatus consists... 

Furthermore, pharmacokinetic administration, distribution, metabolism and excretion (ADME) factors affect drug bioavailability, efficacy and safety, and, thus, are a vital consideration in the selection process of oral drug candidates in development pipelines. Since solubility, permeability, and the fraction of dose absorbed are fundamental BCS parameters that affect ADME, these BCS parameters should prove useful in drug discovery and development. In particular, the classification can used to make the development process more efficient.For example, in the case of a drug placed in BCS Class II where dissolution is the rate-limiting step to absorption, formulation principles such as polymorph selection, salt selection, complex formation, and particle size reduction (i.e., nanoparticles) could be applied earlier in development to improve bioavailability. 

Consider the formation of nanoparticles of an example where in starting metals studied ternary mixtures of silver, gold and zinc. The mass fraction of each metal in nanosystem was selected approximately equal to the following values Ag - 33.97%, Zn - 37.05%, Au - 28.98%. Phase condensation of metal atoms in nanoparticles, following the heat was simulated for 30 ns. The grouping of the atoms in the nanoclusters is actively carried out in the first moments of time and was accompaitied by the formation of a significant amount of nanoparticles. Later on, the condensation already formed nanoobjects is observed, which leads to a gradual decrease in the number of nanoparticles and an increase in their size (Fig. 4.8). 

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