BERLIN (AP) — Scientists in Germany who developed a new way to make a key malaria drug several years ago have come up with a technique to make the process even more efficient, which should increase global access and reduce the cost.

The new procedure refines a method developed in 2012 at the Max Planck Institute to use the waste product from the production of artemisinin, which is extracted from a plant, to produce the drug itself.

Chemist Kerry Gilmore said Wednesday the new procedure uses the plant's own chlorophyll instead of additional chemicals as catalysts to drive the reaction, directly using the crude materials to produce the drug more efficiently.

He says they're working with the state of Kentucky to start a facility where "we will have the entire supply chain under one roof, going from plants to pill."