Comparison of injection comfort of a new category of cohesive hyaluronic acid filler with preincorporated lidocaine and a hyaluronic acid filler alone.

BACKGROUND: A smooth, cohesive, 24-mg/mL hyaluronic acid (HA) gel with uniform consistency, even flow characteristics, and extended duration was designed for injection into the mid to deep dermis.

OBJECTIVE: To compare injection pain of a HA gel with preincorporated lidocaine with that with a non-lidocaine formulation.

METHODS & MATERIALS: This double-blind study at three centers enrolled 60 subjects, injected with both products, randomly assigned to left or right nasolabial fold. The injecting physician assessed severity of pain and ease of injection. Subjects used a visual analog scale (0-10) for pain assessment. Adverse events were recorded. RESULTS Physician assessment of injection pain was none or mild in 81% of HA gel injections with preincorporated lidocaine and 36% of HA-alone injections (p<.001). Mean pain assessment by subjects was 3.6 for HA+lidocaine and 5.8 for HA alone (p<.001). Ninety-five percent of the injections were considered easy or very easy; a greater percentage of HA+lidocaine injections were rated very easy. Mild to moderate adverse events were reported for both products.

CONCLUSION: The smooth, cohesive HA gel with preincorporated lidocaine increased subject comfort during treatment and improved the injection experience.