The 80% of world depends upon crude drugs. The total recorded plant species in world 2,50,000. Plants used as medicinal plant in world 35,000, total number of plants in India 47,000, plants used as medicinal plant in India 6,000. With the increase of knowledge of drugs, the volume of work also increased a lot and it became impossible for one person to manage them properly.

Thus at this point pharmacy & medicine started developing along two separate paths:

1. a) One group specialized in diagnosing the disease and prescribing the drug and known as the physicians or doctors;
2. b) The other group specialized in collecting, processing, preparing & dispensing the drug and known as the apothecaries or pharmacist.

In this way, Pharmacognosy progressed gradually and formed the basis and beginning of both pharmacy & medicine.

The two main sources considered in the drug development are Natural (Animal/Plant) and Synthetic.