Taxol To Nanotaxol: A Journey Towards Enhanced Drug Delivery

Drug delivery in the field of cancer has undergone a continuous revolution over the past few decades. Development of novel chemotherapeutic agents without the method of delivering them to the tumor site would find no practical application in uprooting the fatal disease of uncontrolled cell proliferation, cancer. This makes the development of drug carriers exceedingly essential for diagnostics and therapy alike. Nanotechnological science has gained impetus in the recent past and has found applications in a plethora of fields. It has managed to create an impact in the field of diagnostics, drug delivery and therapy, equally. Taxol®, a chemotherapeutic agent that was initially obtained from the bark of Taxus brevifolia, moved on to the semisynthetic approach for its synthesis to address the shortage of its natural source. This drug is partially soluble in water and its initial formulation with Cremophor EL manifested as anaphylactic reactions. To do away with these problems and others such as lower circulation time in blood and non-specificity, nanotechnology is now being looked at as a promising solution. Nanotechnological carriers aim at enhancing targetspecificity by functionalization, drug stabilization and preventing its degradation due to physiological conditions, pH, enzymes, etc., demonstrating an Enhanced Permeability and Retention (EPR) effect, prolonged blood circulation and thus better anti-tumor activity, while the side effects being almost negligible. The patents in this chapter aim to highlight how nanotechnology can find practical applications and how one or more than one drugs could be administered in vivo in a sustained fashion. The step-wise development in using this potent anticancer drug (Taxol) involved the use of human serum albumin associated compositions (Abraxane®), cremophor-free formulations (Capxol™, Genexol-PM™), numerous oil-in-water emulsions, liposomes and micelles, use of graphene quantum dots (GQDs) for bioimaging and drug delivery and the use of single-walled and multi-walled carbon nanotubes. It also allows the readers to explore nanodevices that can be turned on and off as and when the need be for localized drug delivery. Enabling the nanocarriers to modulate the pharmacokinetic and pharmacodynamic properties of the drug is another notable feature that some of these nanocarriers possess.

Keywords: Abraxane®, anti-angiogenic, cancer, carbon nanoparticles, Cremophor-free, devices, drug delivery, emulsions, increased tumor specificity, liposomes, micelles, nanocarriers, paclitaxel, prolonged circulation time, protein associated, reduced hypersensitivity, surface-functionalized, Taxol®, Taxus brevifolia, tubulin stabilizing.