An appraisal of the bioavailability enhancers in Ayurveda in the light of recent pharmacological advances

The concept of bioavailability enhancer is new to the modern system of medicine. Basically, this concept originated in Ayurveda and being used in this system of medicine since centuries. Bio-enhancers augment the bioavailability or biological activity of drugs when co-administered with principal drug at low doses. Ayurveda is using several drugs such as Piper longum Linn., Zingiber officinale Rosc., and Glycyrhhiza glabra Linn. as bio-enhancers and different methods for bio-enhancing since centuries. The bio-enhancement leads to reduction in therapeutic dose of principal drug, thus reducing the possibilities of toxicity and side effects of drug, potentiating the efficacy, reducing the resistance, decreasing the requirement of raw material for drug manufacture, and ultimately benefitting to the world economy by reducing the treatment cost. This review article attempts to consolidate different drugs as well as methods being used traditionally for enhancing bioavailability in Ayurvedic system of medicine and to discuss their possible mechanism of action. Authentic subject material has been reviewed from different Ayurvedic texts and from different related research and review articles. Thus, it is a humble effort to explore the different aspects of bio-enhancers including therapeutic techniques such as Shodhana, the drugs such as Pippali, and properties such as Yogavahi and Rasayana, which have been described in Ayurveda along with their mechanism of action and uses wherever available.