Polymeric drug delivery systems nanocapsules

Nanoparticles, i.e. particles with a size usually in the range 50-1000 nm, have drawn the attention of researchers designing drug-delivery systems that can be injected intravenously owing to their small size. Nanoparticle is a general name for nanospheres and nanocapsules. Nanospheres have a matrix-type structure, whereas nanocapsules are hollow and have a liquid core surrounded by a polymeric wall, as illustrated in Figure 4.34. 

Nanoparticles Nanoparticles have been among the most widely studied particulate delivery systems over the past three decades. They are defined as submicrometer-sized polymeric colloidal particles ranging from 10 to 1000 nm in which the drug can be dissolved, entrapped, encapsulated, or adsorbed [206]. Depending on the preparation process, nanospheres or nanocapsules can be obtained. Nanospheres have a matrixlike structure where the drug can either be firmly adsorbed at the surface of the particle or be dispersed/dissolved in the matrix. Nanocapsules, on the other hand, consist of a polymer shell and a core, where the drug can either be dissolved in the inner core or be adsorbed onto the surface [207],... 

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