Recent developments in pharmaceutical salts: FDA approvals from 2015 to 2019

Drugs with poor aqueous solubility are liable to have low and variable oral bioavailability [1,2]. A recent estimate states that more than 60% of new molecular entities (NMEs) possess suboptimal aqueous solubility, which might be the reason for their unpredictable clinical response [3,4]. Hence, it is important to identify solubility enhancement strategies for NMEs. From an analysis of present-day drugs [in the US Food and Drug Administration (FDA) Orange Around half of the new molecular entities approved by the US Food and Drug Administration (FDA) are pharmaceutical salts. The pharmaceutical salts have been on a continuous growth trajectory since the approval of the first salt form in 1939. This review aims to provide updates on pharmaceutical salts approved by the FDA between 2015 and 2019. The five-year drug-approval database contains 61 pharmaceutical salts, featuring a diverse range of counterions; however, hydrochlorides are the most abundant. The chemical structures of all pharmaceutical salts in each class are presented here, along with their therapeutic indications and date of approval. The reason behind the selection of a particular counterion and the technical superiority achieved by the salt form over the free active pharmaceutical ingredient base are also discussed.

Automated summary

Drugs with poor aqueous solubility can have low and unpredictable oral bioavailability, so it is important to find strategies to enhance solubility. Around half of the new molecular entities approved by the US FDA are pharmaceutical salts, which have been steadily growing since 1939. This review provides updates on 61 pharmaceutical salts approved by the FDA between 2015 and 2019, detailing their chemical structures and therapeutic indications.