Entrepreneur Martin Shkreli has acquired the rights to a life saving AIDs pill – and has jacked up the price from $13.50 to $750, all in the name of profit.

Turing Pharmaceuticals, founded by former hedge fund manager Martin Shkreli, acquired the rights to the life saving pill Daraprim in August – on Sunday, he announced that the new revised cost would be over 50 times the original selling price for a single pill.

The Infectious Diseases Society of America and the HIV Medicine Association both wrote a joint letter to Turing Pharmaceuticals, heavily criticising Shkreli’s decision, saying that it is “unjustifiable for the medically-vulnerable patient population” and also that it was “unsustainable for the health care system.”

“Please help us improve public health by immediately implementing a rational and fair pricing strategy for pyrimethamine that keeps treatment for a potentially fatal condition accessible to our patients,” the letter read.

The new price means that people in need of the pill, which has been in existence for over 60 years, will be paying hundreds of thousands in treatment every year.

Shkreli defended the price hike, saying, ““We need to turn a profit on the drug. This isn’t the greedy drug company trying to gouge patients, it is us trying to stay in business.”

“This is still one of the smallest pharmaceutical products in the world,” he added. “It really doesn’t make sense to get any criticism for this.”

Last year, Shkreli was fired from his previous position at Retrophin, Inc, for allegedly using the company money as his own “piggy bank” to pay back angry hedge fund investors.