An efficient method for transition metal-free halogen bond-assisted regioselective C–H arylation of 2-phenylimidazo-[1,2-a]­pyridines under visible-light condition has been developed. The halogen bond between an aryl halide and base KO t Bu initiates an electron transfer process and generates an aryl radical, which catalyzes its coupling with 2-phenylimidazo-[1,2-a]­pyridines to give arylated products in good yield. Several control experiments, density functional theory calculations, and ultraviolet–visible analysis indicate the presence of a halogen bond between an aryl halide and KO t Bu. This methodology has been successfully utilized to synthesize antileishmanial agents.

No abstract

Tobramycin is a potent antimicrobial aminoglycoside that can be used to treat ocular infections. Its solubility and bioavailability are limited, so its solid dispersion was prepared using PVP-K30, HPMC and Beta cyclodextrin by solvent evaporation technique. This solid dispersion was formulated as an eye drop using sodium chloride, EDTA and benzalkonium chloride. Totally 9 formulations were prepared. The in-vitro dissolution profile of optimised formulation (F6) showed 85.1% drug release at the end of 2nd hour. The optimized formula was evaluated which showed no microbial growth, and drug content uniformity was 80.12% to 85%. The optimized formulation was evaluated for clarity, pH, isotonicity, microbial growth, stability and in vitro diffusion studies and all these showed acceptable results.