On September 26, 2023, Nexus Pharmaceuticals, LLC announced that it had received approval from the U.S. Food and Drug Administration (FDA) for Fluorescein Injection, USP. Nexus Pharmaceuticals is a maker of generic drugs.
Fluorescein is a dye that can be used as an imaging agent. In response to excitation by blue light, fluorescein will emit yellowish-green light. Accordingly, the molecule can be intravenously injected and used to image vasculature.  Fluorescein is commonly used for ophthalmological testing. Fluorescein may be particularly useful for imaging portions of the eye, such as the retina and choroid vasculature.  As another example, damage to the epithelium of the cornea can be detected using fluorescein, as aqueous humor may leak through the damaged epithelium and mix with the fluorescein, changing the fluorescein signal intensity. Fluorecein may be useful for imaging other tissue too, such as nerves and colorectal tissue. 
Alcon, Inc. had previously received FDA approval for fluorescein injection, USP.  Though Alcon still manufactures fluorescein for injection, one industry group listed fluorescein as subject to a shortage. The shortage may be partially due to the February 2023 bankruptcy of Akorn Pharmaceuticals, which had also manufactured fluorescein. 
Addressing the shortage of fluorescein appears to be Nexus Pharmaceutical’s strategy. As part of the approval announcement, CEO and President Usman Ahmed said that the company is ready to “battle” drug shortages.