Pharmaceutical bad boy Martin Shkreli bragged in an email that hiking the price of a lifesaving drug would be a “very handsome investment,” according to a memo released by federal lawmakers Tuesday.

In May 2015, Shkreli’s company, Turing Pharmaceuticals, was on the cusp of acquiring Daraprim, a drug that treats toxoplasmosis, a parasitic infection, in patients with HIV and cancer.

“Very good,” he wrote the chairman of the board. “Nice work as usual. $1bn here we come.”

Shkreli then told someone outside the company in ­August that the profits would be “huge” — after the firm boosted the medication’s price by 5,000 percent.

He estimated that with the new price, the drug would net the company $375 million a year — ­“almost all of it is profit.”

“We raised the price from $1,700 per bottle to $75,000,” he wrote. “Should be a very handsome investment for all of us.”

Shkreli’s emails were brought to light in memos released by Democratic members of the House Committee on Oversight and Government Reform.

The memos show how Turing Pharmaceuticals and Canada-based Valeant Pharmaceuticals jacked up the prices of medications to boost their bottom lines.

Both companies now face federal investigations over the price spikes — and Shkreli is scheduled to attend a hearing Thursday.

According to the documents, the price hikes at Turing led to skyrocketing patient co-pays — some of which had risen to $16,000.

The brash businessman stepped down from his position after he was indicted in ­December on securities fraud charges.

Turing said in a statement that it had reduced the price of Daraprim for hospitals by up to 50 percent, and used the cash from price hikes for research and patient access programs.