Polymeric Nanoparticles

Pharmaceutical nanoparticles may be prepared using a range of polymeric materials, including self-assembling amphiphilic polymers and hydrophobic polymers. Additionally, in some instances, hydrophilic polymers in combination with chemical or physical cross links provide a source of pharmaceutical nanoparticles. The polymers that have either advanced to clinical or commercial use, or are being advanced to clinical testing are drawn from a narrow chemistry palette. Polymers may be of natural origin, such as the chitosans, including the amphiphilic chitosans, or may be synthetic in origin, such as poly(D,L-lactide-co-glycolide) (PLGA) or the methacrylate polymers, commonly commercially branded as Eudragit® polymers. In essence, the polymers used to make nanoparticles are loaded with drug compounds while the nanoparticles are forming, and these drug-laden particles may then be used to control in vivo drug transport, achieving bioavailability advantages via the intravenous, oral, nose-to-brain, subcutaneous and ocular routes. In some cases, the encapsulation of drug molecules within nanoparticles leads to drug targeting, where more of the drug locates in the area of pathology and less of the drug locates in healthy tissue regions.