Shorstein NH, et al. - Researchers designed a laboratory study and mathematical modeling in order to assess how injection volume and concentration influence dosing and residence time of moxifloxacin in the anterior chamber (AC). They drew moxifloxacin 0.5%/0.05 mL, 0.5%/0.10 mL and 0.15%/0.50 mL into five 1.0 mL syringes each and injected these into tared vials and weighed. Doses delivered were calculated. AC concentrations and elimination rates of drug representing two different AC volumes were modeled for each dosing method. Outcomes revealed less accuracy and less precision in delivered dose when smaller injection volumes of higher concentration moxifloxacin were used; however, the clinical significance of this may vary. According to the model, similar drug AC residence times would be achieved with injection of 0.5%/0.1 mL, and flushing with 0.15%/0.5 mL moxifloxacin. More consistent AC concentrations with differing AC volumes were identified as the advantage offered by flushing.