Future of 5-fluorouracil in cancer therapeutics, current pharmacokinetics issues and a way forward

Background: In addition to exhibiting antitumor potential, antitumor drugs exhibit toxicity due to a poor pharmacokinetic profile. An enormous amount of research has been carried out and is still ongoing to obtain more targeted, potent, and safe drugs to treat cancer, and pharmacokinetic evaluations of anticancer drugs are needed. Objectives: The present review examined different delivery systems and methodologies designed in recent years to investigate the pharmacokinetics of the anticancer drug, 5-fluorouracil (5-FU). These methodologies highlight how the issues of bioavailability, absorption, half-life, targeted neoplastic cell potential, and high therapeutic index of 5-FU are resolved. Results: A number of naturally occurring macromolecules such as modified starch, porphyran, peptides, and folic acids have been found to be successful in vitro to improve the permeability and retention effect of 5-FU against solid tumors. A promising approach for targeted 5-FU delivery to oncoproteins has resulted in a number of potentially sound anticancer nanocomposites. Chitosan nanoparticles loaded with 5-FU have been shown to exhibit cytotoxicity equivalent to 5-FU injections against gastric carcinoma. At the level of inter- and intra-molecular interactions, the co-crystal approach has been found to be successful against colorectal cancer proteins. Because of the 5-FU ligand-like nature and its metal-binding potential, researchers have shifted attention toward the synergistic co-administration of gold complexes with this drug. Conclusions: This study highlighted the techniques used to improve the pharmacokinetics of 5-FU and that “nanocarriers” are a promising approach in this field. The conclusion is supported by solid evidence.