**8.26 Micelles**

Micelles are the polymeric core-shell nanostructures with lypophilic drug core [84]. The lipophobic coating protects the lipophophilic drug from degradation and helps in its solubility. For this reason the lypophilic drugs have long circulation in blood and also mediated the P-gp efflux. The Pharmacokinetic property of the drugs such as fexofenadine could be enhanced when formulated in a self-Nano emulsifying drug delivery system by hampering the CYP450 and P-gp mechanism.

#### **8.27 Mesoporous silica nanoparticles**

Mesoporous silica nanoparticles (MSNPS) are having larger pore size and pore volume, biocompatible in nature and are having high surface area. MSNPS have the capacity to load both anticancer drugs and siRNA together at the same time [85]. This combination can alter the resistance caused by P-gp and in turn can enhance the therapeutic efficacy of the drugs [86].

### **8.28 Polymeric nanoparticles**

Polymers employed are usually natural (Gelatine, chitosan and albumin) or synthetic (poly [D, L-lactic acid], poly [D, L-lactic acid] and poly [ε-caprolactone]) in nature. The techniques [87] used for the preparation of polymeric nanoparticles are salting out, dialysis and microemulsion, interfacial polymerisation, supercritical fluid technique and solvent evaporation. Nanoparticles of Human albumin with abraxane and paclitaxel are formulated for improving the efficacy of metastatic breast and pancreatic cancer [88, 89]. This novel formulation is approved for clinical studies by U.S. Food and drug administration.

*P-Glycoprotein Efflux Transporters and Its Resistance Its Inhibitors and Therapeutic Aspects DOI: http://dx.doi.org/10.5772/intechopen.90430*
