NanoCrystal® colloidal dispersion

This case study deals with the transfer of a complex, proprietary delivery system into a CMO. The delivery system was developed to better deliver poorly soluble compounds, using Alkermes proprietary Nanocrystal Colloidal Dispersion (NCD ) system. The major challenges associated with the transfer of this technology into an Alkermes production facility (Anon, 2012), included ... 

NanoCrystal Colloidal Dispersion —B— NanoCrystal Solid Dosage Form Fig. 8 Pharmacokinetic profiles of three formulations of meloxicam... 

Blanton S A ef a/1997 Dielectric dispersion measurements of CdSe nanocrystals colloids observations of a permanent dipole moment Phys. Rev. Lett. 79 865... 

Ostrander, K. D., Bosch, H. W., and Bondanza, D. M. (1999)iAnitro assessment of a nanocrystal beclo-methasone dipropionate colloidal dispersion via ultrasonic nebulizsffion.J. Pharm. Biopharrp 48 207-215. 

Ostrander, K. D., et al. (1999), An in-vitro assessment of a NanoCrystal beclometha-sone dipropionate colloidal dispersion via ultrasonic nebulization, Eur. I. Pharm. Bio-pharm., 48(3), 207-215. 

Martiradonna, L., Stomeo, T., De Giorgi, M., Cingolani, R., De Vittorio, M. (2006). Nanopatteming of colloidal nanocrystals emitters dispersed in a PMMA matrix by e-beam lithography. Microel. Engin. 83, 1478-1481. 

Poloxamers and other polymeric materials such as albumin may coat the micro- or nano particle, alter their surface characteristics and reduce their phagocytosis and opsonization by the reticuloendothelial system following IV injection. Such surface modifications often result in prolongation in the circulation time of intravenously injected colloidal dispersions.Poloxamers also have been used to stabilize suspension such as NanoCrystal . ... 

In addition to alkanethiols, long-chain fatty acids are used for ligating and assembling metal nanocrystals. A colloidal dispersion of Co nanocrystals capped with fatty acids self-assembles to yield hexagonally ordered arrays similar to those obtained with alkanethiols [162,590]. Ag nanocrystals capped with fatty acids of appropriate lengths yield cubic or hexagonal close-packed... 

Fig. 15 Cascade impactor data for a 10%w/w NanoCrystal beclomethasone dipropionate colloidal dispersion nebulized for 2 s from an Omron MicroAir ultrasonic nebulizer (average of two runs)...

A dispersion is instead a mixture in which the less abundant compound is dispersed, but not molecularly dissolved, in the other component. Examples are a dispersion of a solid phase (powder, nanoparticles, nanocrystals, nanotubes, etc) in a solvent, which is called a suspension, or a dispersion of an immiscible liquid phase in a second liquid, which is called an emulsion. Milk and mayonnaise are familiar examples of emulsions. Aerosols are dispersions of tiny liquid droplets or solid particles in a continuous gaseous phase. The science of aerosols is particularly relevant in order to design filter elements able to remove droplets and particles from air, which can be performed with very high efficiency by polymer nanofibers (Section 4.3.1). Finally, another way to indicate homogeneously mixed dispersions, emulsions or aerosols of nano- or microparticles is colloids. Colloidal dispersions of inorganic nanocrystals or organic nanofibers are familiar examples for nanotechnologists. 

There are many ingenious and successful routes now developed for nanocry stalline syntliesis some rely on gas phase reactions followed by product dispersal into solvents [7, 9,13,14 and 15]. Otliers are adaptations of classic colloidal syntlieses [16,17,18 and 19]. Electrochemical and related template metliods can also be used to fomi nanostmctures, especially tliose witli anisotropic shapes [20, 21, 22 and 23]. Ratlier tlian outline all of tlie available metliods, this section will focus on two different techniques of nanocrystal syntliesis which together demonstrate tlie general strategies. 

A very recent novel hquid-phase route to hollow nanocrystals of cobalt oxide and cobalt sulfide takes advantage of the Kirkendall effect (Section 6.4.1). Injection of sulfur or oxygen into a colloidal cobalt nanocrystal dispersion created hollow nanocrystals of... 

Colloidal synthesis The aqueous synthesis routes could not yield rare earth oxides directly without postheat treatment, while the dry routes usually lead to products with relatively wide size distribution and the nanocrystals could not be dispersed as colloidal solutions. Therefore, it is highly desirable to synthesize R2O3 nanocrystals in suitable nonaqueous solutions. However, the decomposition of rare earth precursor and crystallization of rare earth oxide nanocrystals would require an elevated temperature. Therefore, the solvents are usually with a high boiling point, which are called "high-boiling solvents."... 

The s)mthesis method in high-boiling solvents has been developed to obtain high quality nanocrystals of a number of metals, metal oxides, semiconductors, and inorganic salts. For rare earth compounds, the s)mthesis of rare earth oxides, phosphates and halides would be discussed in this and latter sections of this chapter. The s)mthesis route is considered as colloidal s)mthesis since the products are usually well dispersed NCs in the reaction solution or certain solvents, and the products could only be separated with particular techniques. 

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