Comparison of two lidocaine preparations by in vivo assay methods.

An in vivo study was conducted to determine if there were differences in local anesthetic potency between two commercial brands of lidocaine. The two preparations were evaluated in terms of onset of action, peak effects and duration of action using a double-blink technique. Both products were tested at concentrations of 0.25%, 0.50% and 1%. Each were evaluated for conduction (in rats), topical (in rabbits) and in filtration (in guinea pigs) anesthesia. No clinically significant differences between the two commercial preparations were found.