Lift capabilities of hyaluronic acid fillers

Background: The lift capacity of a filler (ability to oppose deformation and flattening) relates to its suitability for correcting deeper wrinkles and folds, volumizing, and contouring. Lift capacity, considered as a function of both elastic modulus (G'') and gel cohesivity, can be expected to differ among products owing to proprietary manufacturing processes. Objectives: To compare the lift capabilities of 24-mg/ml smooth, cohesive gel fillers (with similar to 6% and similar to 8% crosslinking) and a 20-mg/ml granular consistency gel filler (similar to 2% crosslinking). Methods: G'' was measured using a parallel plate rheometer and the products were subjected to a small oscillatory strain. Cohesivity was measured using a linear compression test (quantitative) as well as a dye diffusion test (qualitative). Results: The 24-mg/ml smooth, cohesive gel filler had a lower G'' coupled with lower susceptibility to yield to a given strain versus the 20-mg/ml granular consistency gel filler. Both 24-mg/ml smooth, cohesive gel filler formulations demonstrated greater resistance to deformation in the linear compression test and lower rates of dye diffusion than the 20-mg/ml granular consistency gel filler. Conclusions: The 24-mg/ml smooth, cohesive HA gel fillers achieve a high lift capacity by combining higher cohesivity with lower relative G'' versus the 20-mg/ml granular consistency gel filler.