distribution

In order to design proper protocol for drug administration is consideration of circadian rhythm in drug pharmacokinetics. Several studies have concluded that all organisms including humans are highly organized by circadian rhythms. These changes in cycles will influence on physiological function thus, can influence on pharmacokinetics phases. Drug pharmacokinetic parameters can be changed according to the time of administration. The main objective of the chronopharmacokinetic study is to control the time of administration which among others can be responsible for variations of drug kinetics but also chronopharmacological effects observed with certain drugs. This article gives brief information regarding the changes of pharmacokinetics of the drug due to circadian rhythms.

Wild yams contribute significantly as diets among the hill tribes of Asia and South West Africa. The nutritional compositions are similar to the cultivated yams except presence of high fibre content and acrid principle. In addition, wild yams are a source of steroid drugs.  In the present paper, extraction and chemical structure of diosgenin, recent change in diosgenin based steroid industry, new sources of steroid, microbiological production of androstanes and chemical synthesis are discussed in addition to the distribution, botanical description, cultivation and economic uses. Conservation and use of genetic resources of wild yams in a sustainable manner has been emphasized.