INDEX freeze-drying

The determination of the molecular weight of nanoparticles is performed by gel permeation chromatography (GPC). The experimental setup consists of a high performance liquid chromatography system with a size exclusion column and a refractive index detector. The nanoparticles are usually freeze-dried and dissolved in tetrahydrofuran for analysis on the system. Poly(styrene) or poly(methylmethacrylate) standards are used to calibrate the column, to enable the determination of number average molecular weight (Mn), as in... 

Water extract of the freeze-dried root, at a concentration of 2 pg/mL, was inactive. Nitrite formation was used as an index of the macrophage stimulating activity . 

In our laboratory, we have prepared stable freeze-dried liposomes containing two antiasthma drugs, namely beclomretasone dipropionate (BDP) and salbutamol sulfate (SS) [44]. The highest liposome stability on rehydration, demonstrated by minimized increases in size measurements (Zaverage) and polydispersity index (PI), was shown when sucrose was employed as a cryoprotectant (Figure 15.3). By contrast, when no cryoprotectant was included, liposome size was increased by approximately 30 times, indicating that SUVs were massively aggregated or converted into MLVs [44]. 

Single fluid nozzle Two fluid nozzle Three fluid nozzle Four fluid nozzle Area equivalent size Equivalent area Atmospheric freeze-drying Drag coefficient Carr s Index... 

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