"Cohesiveness of Hyaluronic Acid Fillers": Evaluation Using Multiple Cohesion Tests

Area of Science:

• Dermal Fillers
• Biomaterials Science
• Rheology

Background:

• Hyaluronic acid (HA) fillers are manufactured via diverse processes, influencing properties like concentration and rheology.
• Cohesion, a measure of gel integrity, is vital but lacks standardized evaluation methods for HA fillers.
• Understanding HA filler cohesion is important for clinicians selecting appropriate products.

Purpose of the Study:

• To evaluate and compare different tests for calculating hyaluronic acid filler cohesion.
• To discuss the significance of HA filler cohesion in product selection.

Main Methods:

• Five distinct hyaluronic acid fillers with varying rheological properties were assessed.
• Cohesion was evaluated using drop weight, compression, tack, and dispersion time tests.

Main Results:

• Cohesion tests produced varied results across samples.
• Samples 2 and 4 demonstrated approximately double the droplet count of Sample 5 in the drop weight test.
• Samples 1, 2, 3, and 4 outperformed Sample 5 in the tack test, with Samples 1, 2, and 3 showing cohesive appearances at 95 seconds in the dispersion test.
• Rheological test results did not correlate with cohesion measures.

Conclusions:

• While standardized tests for hyaluronic acid filler cohesion are absent, the evaluated methods showed consistent results across different products.
• Further research is necessary to establish definitive cohesion evaluation methods and their clinical relevance for product selection.