Martin Shkreli was the ''big pharma bro" who outraged the world by hiking the price of an essential drug from $US13.50 ($18) to $US750 a tablet.

Now a handful of year 11 students in Sydney have shown him up, cooking the same drug in their school lab for about $2 a dose.

Daraprim is an anti-parasitic medicine used to treat infections such as toxoplasmosis and malaria. It is on the World Health Organisation's list of essential medicines.

The drug is used to treat people with low immune systems, such as people living with HIV, chemotherapy patients and pregnant women.