Physiochemical Investigations of Surface Active Ionic Liquids Containing Salicylate Moiety; Enhanced Pharmacological Behaviour and Permeability

Abstract One of the key strategy for enhancing the poor solubility and bioavailability of active pharmaceutical ingredients (APIs) is their conversion to ionic liquids (ILs) form, commonly referred to as API‐ILs. Herein, we report the synthesis and physiochemical investigation of two such API‐ILs based on the salicylate ion, namely benzalkonium salicylate (BzSal) and cetylpyridinium salicylate (CetPySal). To evaluate the pharmacological behaviour of these Sal‐ILs, theoretical studies viz. molecular docking and experimental studies viz . DPPH, FRAP and MIC assay were carried out. The Sal‐ILs have been found to possess antibacterial activity against Enterobacter aerogenes ( E. aerogenes ) , Klebsiella pneumoniae ( K. pneumoniae ), and Proteus vulgaris ( P.vulgaris ) as well as antioxidant potential against the target protein, i.e., NO‐synthase (PDB ID: 6NGJ). Further, as these Sal‐ILs were amphiphilic, so conductivity and UV‐visible measurements were employed to determine their aggregational characteristics both in the absence and presence of certain additives (Alcohols/Tweens). Lastly, the in vitro skin permeation studies have been performed using dialysis membrane, indicating at the higher permeability of Sal‐ILs in comparison to parent salicylic acid.