Polymeric drug delivery systems nanoparticles

Figure 10.3 Structures of polymers and polymeric drug delivery systems sensitive to temperature, near-infrared light, and magnetic fields, (a) Temperature-sensitive biodegradable block copolymer (Kim et al., 2011). (b) NIR-sensitive PLGA microspheres contaming hoUow gold nanoparticles (You et al., 2010). (c) NIR-sensitive hybrid nanogels (Wu et al., 2010).

A large variety of drug delivery systems are described in the literature, such as liposomes (Torchilin, 2006), micro and nanoparticles (Kumar, 2000), polymeric micelles (Torchilin, 2006), nanocrystals (Muller et al., 2011), among others. Microparticles are usually classified as microcapsules or microspheres (Figure 8). Microspheres are matrix spherical microparticles where the drug may be located on the surface or dissolved into the matrix. Microcapsules are characterized as spherical particles more than Ipm containing a core substance (aqueous or lipid), normally lipid, and are used to deliver poor soluble molecules... 

Kumari A, Yadav SK, Yadav SC (2009) Biodegradable polymeric nanoparticles based drug delivery systems. Colloids Surf B 75 1-18... 

Nanoparticles are polymeric colloidal particles that consist of dmg-entrapped macro molecular materials. Nanoparticles represent a comfortable, extended-duration, drug delivery system that has the potential to preferentially adhere to inflamed eyes. 

The potential of polymeric nanoparticles as an ocular drug delivery system has been explored by a colloidal system consisting of an aqueous suspension of nanoparticles. These nanoparticles can be rapidly fabricated under extremely mild conditions with their ability to incorporate bioactive compounds. ... 

FIGURE 53.11 Cartoon diagram showing biodegradable polymeric nanoparticle drug delivery system. The nanoparticle drug delivery system has a dimension of about 50-100 nm. 

In vitro and in vivo biocompatibUity tests are required by government agencies for drug delivery system and biomedical device approval [16]. In vitro dissolution testing is used to assess in vivo performance and is important during formulation development as weU as for product quality assurance. Standardized dissolution methods are under development for novel polymeric formulations such as microspheres, nanoparticles, and in situ forming gels [17]. 

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