Results from a trial showed that dexamethasone reduced death rates by about a third compared with a placebo in severely ill hospitalized COVID-19 patients, University of Oxford scientists said last week, calling the discovery a major breakthrough.

"Aspen has looked at the short-term needs and can provide 10 million tablets in the next three to four weeks. We would look to ramp up further should there be a need for additional product," Saad said without indicating current production volumes.

South Africa's biggest supplier of drugs, with a 22% market share in sub-Saharan Africa, manufactures both the injectable and tablet forms of dexamethasone, which is mainly used for treatment of tumors, asthma and other respiratory ailments.

The South African government has contacted Aspen to source the drug not only for its domestic market but also for rest of the continent, the company said on Monday.

The company has asked the government to indicate required volumes across the continent, Saad said. "Once they give us a sense, we can work out the supply," he added.

South Africa's health ministry on Friday said that the government had a stock of 300,000 ampoules of dexamethasone and could secure supplies from local suppliers.

Saad said the recent revelation by scientists at the University of Oxford had brought in sudden demand for the drug and the company had received orders from the World Health Organization, UNICEF and other bodies.

"We are trying to make sure there is no panic-buying," he said.