Automated evaluation of pharmaceutically active ionic liquids' (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri

Abstract

The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC50). The EC50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs.

Keywords: (Hex)(3)(TDec)PCl; (Hex)(3)(TDec)PD; (Hex)(3)(TDec)PSal; (Hex)(3)(TDec)PTf(2)N; 1-ethyl-3-methyl-imidazolium chloride; 1-ethyl-3-methyl-imidazolium salicylate; 4-methylumbeliferyl acetate; APIs; BACl; BASal; BECl; BED; BESal; BETf(2)N; CetPyCl; CetPySal; DMSO; HCE; Human toxicity; IL-APIs; ILs; MUA; NaD; NaSal; Pharmaceutically active ionic liquids; SIA; Vibrio fischeri; active pharmaceutical ingredients; benzalkonium chloride; benzalkonium salicylate; benzethonium bistriflimide; benzethonium chloride; benzethonium docusate; benzethonium salicylate; cetylpyridinium chloride; cetylpyridinium salicylate; dimethylsulfoxide; emimCl; emimSal; human carboxylesterase; ionic liquids; pharmaceutical active ionic liquids; sequential injection analysis; sodium docusate; sodium salicylate; trihexyltetradecylphosphonium bistriflimide; trihexyltetradecylphosphonium chloride; trihexyltetradecylphosphonium docusate; trihexyltetradecylphosphonium salicylate.