Laboratory Research
Multiple sections of intact and non-intact human skin surrogate was placed in a solution that coated the underside of the skin surrogate. This solution was designed to mimic blood plasma, which would receive the transdermally absorbed lidocaine from the lidocaine hydrogel product. Once the lidocaine hydrogel was applied to the skin surrogate, lidocaine absorption was analyzed every hour for 26 hours.
Results: Maximum lidocaine absorption occurred two hours after application for both intact and non-intact skin. Lidocaine absorption then rapidly decreased the following four hours. Throughout the study, maximum lidocaine blood level was calculated to be 200ng/mL. At 25 hours, the lidocaine level that was absorbed between intact and non-intact skin was not significantly different.
Discussion:
The lidocaine containing hydrogel did not significantly increase risk for lidocaine toxicity in non-intact skin, with the maximum blood level for an average person calculated to be 200ng/mL, well below the accepted threshold of 1-5µg/mL. This study suggests that the 2% lidocaine collagen hydrogel could be a preferable alternative to topical lidocaine to control pain and promote wound healing.