Managing efficacy and toxicity of drugs: Targeted delivery and excretion

Medicine is a natural companion of mankind in the present era for mere survival from the deadly diseases in ever-increasing polluted environments. Hence, in recent years, major focus of pharmaceutical, medicinal and biophysical research has been navigated in exploring and developing new and simple avenues to enhance the efficacy of the administered drugs on one hand and to get rid of, or at least reduce, the toxic side effects of the excess drugs accumulated in human body on the other. A potential approach to amplify the efficacy of the administered drug is to develop proficient targeted drug delivery systems (DDSs). This review provides an essence of some newly developed simple but prospective strategies on enhancing the efficacy of drugs/bioactive molecules exploiting various drug delivery systems like micelles, cyclodextrins, liposomes etc. to serve the purpose of targeted delivery towards DNA, by endogenous and/or exogenous means. Improved bio-availability and solubilization of ionic drugs within the less polar target regions from the bulk aqueous phase has also been achieved through the introduction of some physiologically permissible salts. In the other context, in vitro and in vivo studies demonstrate a simple technique for easy removal of the excess adsorbed drug molecules from the cell membranes/lipid bilayers by exploiting health-amiable supramolecular assemblies. In this review, we summarize the recent experimental findings, mostly from our lab, encompassing the development of simple biocompatible methods to enhance the benevolent role of drugs through their safe, effective and convenient administration. It also presents easy and effective means to remove the excess adsorbed drugs from human body to diminish their malign effects. These prospective approaches of drug delivery and excretion of drug molecules have promising roles to play from both physicochemical and pharmaceutical perspectives, ensuring enhanced bioavailability of drugs as well as disposing of drug-induced adverse side effects.