Top-down and bottom-up approaches in production of aqueous nanocolloids of low solubility drug paclitaxel

Abstract

Nano-encapsulation of poorly soluble anticancer drug was developed with sonication assisted layer-by-layer polyelectrolyte coating (SLbL). We changed the strategy of LbL-encapsulation from making microcapsules with many layers in the walls for encasing highly soluble materials to using very thin polycation / polyanion coating on low soluble nanoparticles to provide their good colloidal stability. SLbL encapsulation of paclitaxel resulted in stable 100-200 nm diameter colloids with high electrical surface ξ-potential (of -45 mV) and drug content in the nanoparticles of 90 wt %. In the top-down approach, nanocolloids were prepared by rupturing powder of paclitaxel using ultrasonication and simultaneous sequential adsorption of oppositely charged biocompatible polyelectrolytes. In the bottom-up approach paclitaxel was dissolved in organic solvent (ethanol or acetone), and drug nucleation was initiated by gradual worsening the solution with the addition of aqueous polyelectrolyte assisted by ultrasonication. Paclitaxel release rates from such nanocapsules were controlled by assembling multilayer shells with variable thicknesses and are in the range of 10-20 hours.

Development of docetaxel nanocrystals surface modified with transferrin for tumor targeting

“…In the top-down method, the particle size of drugs is reduced by high-pressure homogenization or milling 37–39. On the other hand, in the bottom-up method, particle size is controlled by the probe sonication method; furthermore, particle size growth is inhibited by using antisolvents 40,41. The preparation method of top-down method is as follows: first, presuspension was prepared by a homogenizer and then the presuspension was processed using a high-pressure homogenizer or microfluidizer.…”

Advances in integrative nanomedicine for improving infectious disease treatment in public health

“…Empirical studies demonstrate that using NPs for delivery of drugs [95, 96] and/or herbs [14] can (a) better reach their intended targets in the cells of the body; and (b) reduce the total amount of an agent needed to accomplish a therapeutic effect [74]. NP herb or drug forms can not only bypass or dramatically improve upon the poor gastrointestinal absorption and/or solubility problems that limit the usefulness of many different bulk form agents [15, 97], but they can also cross the blood-brain barrier for enhanced delivery into the central nervous system, e.g., for antiretroviral drugs in HIV/AIDS [98].…”

Lapatinib/Paclitaxel polyelectrolyte nanocapsules for overcoming multidrug resistance in ovarian cancer

“…[10][11][12][13] Among the wide variety of novel formulations, previous studies have shown that sonication-assisted layer-by-layer (SLBL) nanoassembly technique can be used efficiently for the nanoencapsulation of poorly soluble anticancer drugs. 14,15 Under powerful ultrasonication, the air bubble that was dissolved in water underwent the formation and implosion of the cavity, followed by the jet flow. Thus an extreme physicochemical environment was created.…”