Advanced Polymeric Nanoparticulate Drug Delivery Systems: Formulation Strategies, Controlled Release, Surface Engineering, and Site-Specific Therapeutic Targeting

Nanoparticulate drug delivery systems have diverse advantages over traditional pharmaceutical drug carriers, and include advantages such as the stabilization of drugs, the controlled release of drugs, increasing the bioavailability of drugs, and the improved targeting of drugs at their specific site of action. Within this framework, polymeric nanoparticles consist of nanospheres and nanocapsules, and are some of the most advanced systems available for the encapsulation and delivery of drugs. This review is intended to describe some of the advanced principles of polymeric nanoparticle formulation, including solvent evaporation, spontaneous emulsification or solvent diffusion, polymerization, coacervation or ionic gelation, supercritical fluid technology, and particle replication in non-wetting templates. Particular emphasis is given to the characteristics of polymeric nanoparticles, including drug release, and their bio-distribution characteristics. Finally, this review highlights the use of PEGylation and ligand-mediated modifications to reduce the uptake of nanospheres and nanocapsules by cells, increase the circulation time of nanoparticles, and to optimize targeting to receptors.