Lift capabilities of hyaluronic acid fillers

Abstract

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 ∼6% and ∼8% crosslinking) and a 20-mg/ml granular consistency gel filler (∼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.

Key Words::

• cohesivity
• dermal fillers
• hyaluronic acid
• viscosity

Acknowledgements

Funding for editorial support was provided by Allergan, Inc., Irvine, CA, USA. Writing and editorial assistance was provided by Paula G. Davis, PhD, Ramana Yalamanchili, PhD, MBA, and Greg Tardie, PhD of Health Learning Systems, Parsippany, NJ, USA.

Disclosures: Drs Tezel and Borrell and Mr Leslie are employed by Allergan, Inc., Santa Barbara, CA, USA.