Nanoparticles/nanospheres

The procedure chosen for the preparation of lipid complexes of AmB was nanoprecipitation. This procedure has been developed in our laboratory for a number of years and can be applied to the formulation of a number of different colloidal systems liposomes, microemulsions, polymeric nanoparticles (nanospheres and nanocapsules), complexes, and pure drug particles (14-16). Briefly, the substances of interest are dissolved in a solvent A and this solution is poured into a nonsolvent B of the substance that is miscible with the solvent A. As the solvent diffuses, the dissolved material is stranded as small particles, typically 100 to 400 nm in diameter. The solvent is usually an alcohol, acetone, or tetrahydrofuran and the nonsolvent A is usually water or aqueous buffer, with or without a hydrophilic surfactant to improve colloid stability after formation. Solvent A can be removed by evaporation under vacuum, which can also be used to concentrate the suspension. The concentration of the substance of interest in the organic solvent and the proportions of the two solvents are the main parameters influencing the final size of the particles. For liposomes, this method is similar to the ethanol injection technique proposed by Batzii and Korn in 1973 (17), which is however limited to 40 mM of lipids in ethanol and 10% of ethanol in final aqueous suspension. 

Keywords Membranes Microgels Microparticles Microspheres Molecular imprinting Monoliths Nanogels Nanoparticles Nanospheres... 

The drug can be dissolved, entrapped, encapsulated, or attached to a nanoparticle matrix, and depending upon the method of preparation, nanoparticles, nanospheres, and nanocapsules can be obtained (Soppimath et al. 2001). 

Keywords Block copolymer Cell-mediated delivery Liposome Mulddrug resistance Nanofiber Nanogel Nanoparticle Nanosphere Nanosuspension Nanotube... 

For ophthalmic applications, properly formulated drug-loaded nanoparticles (DNPs) are reported to provide ease of application just like eye drop solutions, with the added advantage of being patient friendly, due to less frequent application and extended duration of retention in the extraocular portion. The drug may be attached to a nanoparticle matrix, or dissolved, encapsulated, and entrapped, giving rise to different terminologies as nanoparticles, nanospheres, or nanocapsules. " ... 

Scanning electron microscopy (SEM) is one of the very useful microscopic methods for the morphological and structural analysis of materials. Larena et al. classified nanopolymers into three groups (1) self-assembled nanostructures (lamellar, lamellar-within-spherical, lamellar-within-cylinder, lamellar-within-lamellar, cylinder within-lamellar, spherical-within-lamellar, and colloidal particles with block copolymers), (2) non-self-assembled nanostructures (dendrimers, hyperbranched polymers, polymer brushes, nanofibers, nanotubes, nanoparticles, nanospheres, nanocapsules, porous materials, and nano-objects), and (3) number of nanoscale dimensions [uD 1 nD (thin films), 2 nD (nanofibers, nanotubes, nanostructures on polymeric surfaces), and 3 nD (nanospheres, nanocapsules, dendrimers, hyperbranched polymers, self-assembled structures, porous materials, nano-objects)] [153]. Most of the polymer blends are immiscible, thermodynamically incompatible, and exhibit multiphase structures depending on the composition and viscosity ratio. They have two types of phase morphology sea-island structure (one phase are dispersed in the matrix in the form of isolated droplets, rods, or platelets) and co-continuous structure (usually formed in dual blends). 

Importance of Engineering Chitosan-Based Nanoparticles, Nanospheres, and Nanogels 105... 

Chitosan Natural Microsphere, Microcapsule, Nanoparticles, Nanospheres Diltiazem hydrochloride, Fluorouracil, Nifedipine, Cisplastin, Acetaminophen, Amino acid. Insulin, Lactobionic acid... 

S.S. Guterres, M.P. Alves, and A.R. Pohlmann, Polymeric nanoparticles, nanospheres and nanocapsules, for cutaneous applications. Drug Target Insights, 2 (2), 147-157, 2007. 

Nanodelivery systems can be defined as colloidal particles below lOOOnm size, such as nanospheres, nanocapsules, micelles, liposomes, solid lipid nanoparticles, nanocrystals, etc. The drug can be dissolved, entrapped, encapsulated, or attached to a nanoparticle matrix. Polymeric nanoparticle is a collective term given for any type of polymer nanoparticle (Soppimath et al., 2001). Generally, two main strategies are employed for their preparation the dispersion of preformed polymers and the polymerization of monomers. Depending on the process used for the preparation of nanoparticles, nanospheres (matrix-type), or nanocapsules (reservoir-type) can be obtained (Couvreur, 2013 Fattal et al., 2012 Rao and Geckeler, 2011). 

In the third category is included the solid volumetric with a structure on the scale of nanometers. Due to its vast applicability—electronic, chemical, optical, and biochemistry industry, among others—materials such as nanoparticles, nanospheres and others have been gaining the attention in academic and industrial areas [6]. 

Polymeric nanoparticles are nanoparticles, which are prepared from polymers. Polymeric nanoparticles forms (1) the micronization of a material into nanoparticles and (2) the stabilization of the resultant nanoparticles [8]. As for the micronization, one can start with either small monomers or a bulk polymer. The dmg is dissolved, entrapped, encapsulated or attached to a nanoparticles and one can obtain different nanoparticles, nanospheres or nanocapsules according to methods of preparation [9]. Gums, Gelatin Sodium alginate Albumin are used for polymer based drag delivery. Polymeric nanoparticles are prepared by Cellulosics, Poly(2-hydroxy ethyl methacrylate), Poly(N-vinyl pyrrolidone), Poly(vinyl alcohol), Poly(methyl methacrylate), Poly(acrylic acid). Polyacrylamide, Poly(ethylene-co-vi-nyl acetate) like polymeric materials. Polymer used in drag delivery must have following qualities like it should be chemically inert, non-toxic and free of leachable impurities [10]. 

Nanocapsules (hollow nanoparticles, nanospheres) are submicrometric colloidal objects composed of a liquid core surrounded by a thin silicone shell. The vesicle templating, solidification in emulsion and solidification of vesicles are the main methods for preparation of the silicone nanocapsules. The vesicle templating method is based on imprinting in the prepared materials the shape and size of the vesicles used as a template. Among the most popular templates are vesicles created from phospholipids (liposomes), double-tailed... 

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