Aparna S

Chronobiology is the science deals with the biological mechanism of the diseases according to a time structure. The variations in the pharmacological actions of various drugs over a period of time. Putting this all together, chronotherapeutics considering the timing of drug delivery according to inherent activities of a disease over a certain period of time. With the advancement in the field of chronobiology, modern drug delivery approaches have been elevated to a new concept of chronopharmacology, that is the ability to deliver the drugs on a specific preprogrammed pattern i.e. at appropriate time and at appropriate site of action. chronopharmaceutical technology advantageous to the application range, the ease of manufacturing, the cost effectiveness and the flexibility in the pharmacokinetic profile. It also provide perfect therapy by targeting to the specific site at most appropriate time. The mechanisms are associated with the 24- hour rhythms of biochemical and physiological behavioral processes under the control of the circadian clock. Research in chronobiology described the importance of biological rhythms in drug delivery that timing of drug delivery has significant effect on treatment success. So this can be concluded that chronomodulated drug delivery system provides a solution for delivery of drugs for those disease conditions regulated by circadian rhythm.  present article gives an overview of various types of chronomodulated drug delivery systems and also tries to highlights some of the recent advances being done in chronopharmaceutical drug delivery system.

Anxiety disorders are marked by excessive fear, often in response to specific objects or situations and in the absence of true danger and they are extremely common in the general population. According to a recent epidemiological study, the lifetime prevalence of any anxiety disorder is 28.8%. Anxiety disorders are associated with impaired workplace performance and hefty economic costs. The clinical applications of benzodiazepines as anxiolytic are limited by their side effects. The aim of the present study is to investigate the effects of aqueous and ethanolic extracts of Solanum Nigrum leaves.  Elevated plus maze test, light/dark test used. In the elevated plus maze, aqueous and ethanolic extracts (400mg/kg; p.o) showed an anxiolytic effect by increasing the percentage of time spent in open arms and the percentage of open arm entries as compared to control group.. In the light/dark transition test, aqueous extracts (400mg/kg; p.o) had increased the time spent in light area, latency to enter dark chamber and tunnel crossing. Whereas, ethanolic extract of (400mg/kg; p.o) has showed significant result. These results suggested that the extracts of Solanum Nigrum leaves possessed anxiolytic effect in mice, in contrast to diazepam, had no inhibitory effect on locomotion in these tests, its side effect profile might be superior to the benzodiazepines.