We often travel via public transport to attend meetings or functions. What if that vehicle goes all around the world, but not the destination where we want to go? Or what if it keeps wandering around and delays the time of arrival at the destination?

Will we be able to attend the same meeting or function?

Obviously not.
So the same goes with drugs (medicines) that we intake. When we swallow a drug, it has to reach a site within the body to perform it’s activity. Moreover, hitting the targeted site in proper time is a must, for effectiveness of the drug.

This concept of drug delivery at the site of action through the stream within the body is known as Bioavailability. By definition, “Bioavailability refers to the extent and rate at which the active moiety (drug or metabolite) enters systemic circulation, thereby accessing the site of action.”

A drug is formulated including several components like actual drug moiety, fillers, flavonoids, bio-enhancers, colorants, etc. The bio-enhancers amongst these are the agents that enhance the bioavailability and efficiency of a drug. In Ayurveda, the concept of bio-enhancers is known as Yogavahi. The increased bioavailability of a biomolecule by another unrelated chemical is the hallmark of polyherbal formulations of Ayurveda. Yogavahi is used to enhance bioavailability, efficiency of the drug especially which are ingested orally and to enhance distribution of drug within tissues. Some Yogavahis are termed as Anupaana and Sahapaana. Anupaana means, medicaments are given simultaneously with the food in order to increase the efficiency of medicaments; such as “Amrita Dhara ” drops used for gastrointestinal diseases are ingested by putting drops on sugar to increase its potency. Whereas, Sahapaana means, the
additional substance that acts as a vehicle which is added to medicaments while manufacturing; like Brahmi ghrita viz. clarified butter is used.

Properties of Yogavahi:

1.They are tolerable to most humans.

2.They are potent even at low concentrations.

3.Dosage formulation becomes easy.

4.It enhances Bioavailability and bio-efficiency of drugs.

5.It is non toxic.

Benefits of using Yogavahi:

1.It increases Bioavailability of drugs.

2.It reduces the drug dose.

3.It reduces drug resistance.

4.It reduces side-effects of drugs.

5.It increases drug efficiency.

In Ayurveda, raw spices and herbs are recommended to be cooked, because while cooking, herbs and spices are exposed to heat and molecular interaction between oil or ghee and spices or herbs, causes interaction of active components. It also helps to sanitize unwanted toxic materials present in raw spices and herbs. It also helps to access digestive and other systems. Almost all the spices are used as Yogavahi, which help to break down proteins, carbs, fats when there is a need.

A simultaneous use of Yogavahi enhances the effect as well as reduces the side effect. Some Yogavahis which are found in plants are piperine, allicin, curcumin, ginger, caraway, peppermint oil, aloe, black curcumin, naringin, etc.

Besides Yogavahi, there are several ways in which Bioavailability of a drug increases. Those are:

1.Bhaishajya Kala :
It is essential to take medicines on time in relation to time of intake of food. Ayurveda has been mentioned ten times for the administration of drugs, which helps to increase absorption rate of drugs. This concept was developed based on frequency of drug to be administered, their effect on Doshas and to improve efficiency of a drug.

Bhavana is a special method used for enhancing Bioavailability of drugs. These drugs are finely crushed and mixed with svarasa, kvatha, etc. of the other drug during manufacturing of drugs to increase its effectiveness. One such important example of Bhavana Dravya is Gomutra. It is mostly used in its distilled form which increases Bioavailability of antimicrobial, antifungal and anticancer agents.

These drugs are claimed for their bio-enhancing activities. These include Madhuyashti, Lashuna, and Ghritkumari herbs.

It is a type of management described in Ayurveda. It’s a type of bio-purification in order to eliminate the disturbance in Dosha to prevent further disorders. Samshodhana increases the power of Agni, which leads to increase in digestion power and absorption of nutrients and drugs. Thus, it increases the Bioavailability of the drug. The bio-purification cleanses the body channels, thus, improves patency, microcirculation and flow of biomolecules. It also aims for detoxification of the body

5.Yoga and Kalpanas:
Ayurveda has described various types of Kalpanas like Savarasa, Kvatha, Phanta, etc; and formulations like Choorna, Avaleha, Asava, Arishta, Guggulu, etc. These are the drugs which are finely coursed in order to gain maximum absorption which ultimately leads to increase in Bioavailability of the drug.

6.Concept of Purana Aushadhi:
The drugs like Jaggery, Pippali, Ghrita, Vidanga, etc are advised to take after storage of a year, in Ayurveda. This is because, it leads to increase in potency and if co-administered with other drugs, leads to increase in Bioavailability of those drugs.

7.Concept of action – augmenting drugs:
Some drugs are only used with other drugs in order to increase their potency. These types of bio-enhancers include Madhuyashti and Vacha and other drugs like Snehopaga, Svedopaga, Vamanopaga, etc. These drugs promote the action of principal drugs, thus, leading to Bioavailability of the drugs.

8. Penetration enhancers:
The drugs which are administered via topical or transdermal route to increase their Bioavailability are known as penetration enhancers. These drugs are delivered through skin for systematic and local circulation. In Ayurveda, the use of Lavana along with oil is mentioned.
Lavana mixed with oil helps to open Srotas due to the penetrating power of oil, thus resulting in increased Bioavailability.

Thus, from the above context the importance of bio-enhancers in formulation of drugs is noted. In order to reduce the dosages and activity of the drug moiety, it becomes necessary to mix various types of bio-enhancers.