Proton decoupled 19F NMR spectroscopy of drugs used in eye treatment

The potential for detecting fluorinated compounds in a 2.35 T nuclear magnetic resonance system was assessed to evaluate the possibility for in vivo monitoring of fluorinated drugs applied to the eye. Time-share proton decoupled F-19 NMR spectroscopy was implemented for signal enhancement in an experimental eye model. Signal-to-noise in F-19 NMR spectra of dexamethasone phosphate was enhanced by 56%. However, decoupling did not enhance S/N for ciprofloxacin. The obtained detection limit of 0.1-0.2 mu mol did not enable detection of drugs at therapeutic concentrations in the eye. Higher magnetic field and improved coil and detection technology might enable future in vivo monitoring of drugs in the eye.