pH and its applications in targeted drug delivery.

[Display omitted] • pH is vital for the normal functioning of the body. • Drug targeting has been widely used to increase efficacy and reduce adverse effects. • pH variation in different tissues and change in pH in some diseased tissues has been used as an opportunity to deliver drugs. • pH-responsive drug delivery is an attractive platform for targeted drug delivery. Physiologic pH is vital for the normal functioning of tissues and varies in different parts of the body. The varying pH of the body has been exploited to design pH-sensitive smart oral, transdermal and vaginal drug delivery systems (DDS). The DDS demonstrated promising results in hard-to-treat diseases such as cancer and Helicobacter pylori infection. In some cases, a change in pH of tissues or body fluids has also been employed as a useful diagnostic biomarker. This paper aims to comprehensively review the development and applications of pH-sensitive DDS as well as recent advances in the field. [ABSTRACT FROM AUTHOR]