Lift capabilities of hyaluronic acid fillers

Abstract
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. To compare the lift capabilities of 24-mg/ml smooth, cohesive gel fillers (with ~6% and ~8% crosslinking) and a 20-mg/ml granular consistency gel filler (~2% crosslinking). 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). 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. 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.