The two men would supply drugs to rave parties in posh areas of Delhi, Chandigarh and other states.
Police said Ashok Kumar, 45, and Lalmuankima, 29, residents of Adarsh Nagar in Delhi and Mizoram respectively, were arrested on a tip-off on Monday night when Kumar came in his car to hand over the ephedrine to Lalmuankima in Pochanpur village of Dwarka.
"They disclosed that they used to prepare ecstasy (party drug) with the help of ephedrine which they supplied to rave parties in posh areas of Delhi and Chandigarh, Mizoram and northeast states and parts of Punjab," Deputy Commissioner of Police Sanjeev Kumar Yadav said.
"Kumar earlier used to work in a pharmaceutical company in Delhi and supply drugs collected from pharma companies to various parties. He gathered knowledge about the illicit use of ephedrine in preparing party drug tablets," Mr Yadav said.
"This drug is widely used by party revellers in Delhi and the National Capital Region (NCR). The ephedrine tablets are also mixed with drinks and consumed in rave parties," the officer added.
"Lalmuankima said that he is working for Aizawl and Mizoram-based drug traffickers and had come to Delhi to collect the drug consignment from Ashok Kumar in order to deliver it to a foreign national living in Dwarka," he added.