The approvals granted to first-of-a-kind drugs increased last year, with the annual numbers of new U.S. drugs reaching their highest level in 19 years, CBS News reports.

The FDA approved 45 drugs with never-before-sold ingredients in 2015. Last year, the FDA approved 41 drugs, which had previously been the highest number since 1996.

The rising figures of the approvals indicate that the medical industry is now focusing on drugs for rare and hard to treat diseases. Such drugs are often accompanied by streamlined reviews, extra patent protections and higher price tags.

In 2015, the drug called flibanserin was one of the most highly publicized drugs approved. It was a first-of-its-kind medication to boost women's sex drive. The FDA had rejected it twice before, before it was finally approved in 2015.

In the same year, the FDA also approved the first 3D printed drug, a dissolvable tablet called Spritam from Aprecia Pharmaceuticals, which is used to treat certain types of epileptic seizures.

According to U.S. News, between the years 2007 and 2011, only one in 19 drugs entering early-stage testing actually reached the market, according to industry data analyzed by Bernstein's Tim Anderson.

In contrast, one in 13 early-stage drugs is able to get the approval and enter the market now.

"These improvements hopefully reflect the pay-off from the industry's conscious decade-long efforts to 'turn around' R&D," Anderson told investors in a research note last year.