In vitro evaluation of once a day chronotherapeutic drug delivery system of Gymnema sylvestre

Gymnema sylvestre is a potent antidiabetic plant used in indigenous system of medicine. It targets several of the etiological factors connected with diabetes and obesity and thus can offer holistic treatment. However the dosage form in which it is administered is traditional and conventional resulting in reduced efficacy of the drug. The method by which a drug is delivered can have a significant effect on its efficacy, if the modern drug delivery technology is applied to G. sylvestre, it has a potential to synergize benefits of both the drug and the delivery system. Diabetes is one of the diseases where the constant drug levels are not preferred but needs a pulse of therapeutic concentration when the blood sugar levels are high. Chronotherapeutic drug delivery systems has a specificity in delivering therapeutic amount of drug in a burst at circadian timings correlated with specific pathological need to achieve maximum drug effect. The objective of the current study is to apply chronotherapeutic drug delivery based on time controlled approach to G. sylvestre. The drug delivery system is designed to achieve three pulsatile drug deliveries from a single formulation at the time when the blood sugar levels are high. The various components of the system were formulated, evaluated and optimized for the desired drug release. Also, as one of the main mechanisms of action of Gymnema is inhibition of glucose absorption which is exerted in the small intestine and as oral use of Gymnema may cause irritation of the gastric mucous membrane and reflux, the chronotherapeutic formulations were modified so as to make the drug available at the site of action and probably the site of absorption, as well as to prevent the side effects in the stomach. The developed system was able to achieve the objective of integrating modern method of drug delivery with herbal drug for once a day therapy of G. sylvestre with enhanced therapeutic efficacy. But further clinical studies should be warranted to test the efficacy of this system.