ABSTRACT
The expression "as sure as night follows a day" emulates those certain cycles in the environment that are always stable. Circadian rhythms are a group of processes that occur within the body in synchronisation with the external factors in a 24 h cycle. Changes in lifestyle and work shifts have disrupted these stable rhythms, which is a leading cause of lifestyle diseases. Associations between these biological clocks and diseases are abundant. However, it is also known that certain drugs work more efficiently and have minimum toxicity when given during a particular phase of the circadian cycle. Chronotherapeutics focuses on treating diseases according to the endogenous processes which mediate xenobiotic metabolism and drug response at a cellular level. Therefore, treatment of those diseases that show aggravation of symptoms according to the circadian rhythms at a particular time is highly beneficial by chronotherapy. In this article, we have emphasised how the changes in rhythms caused diseases and how chronotherapeutic approaches such as controlled drug release technologies can be a better option for these circadian manipulations that seem to influence all types of disease conditions.