Rheological Properties of Several Hyaluronic Acid-Based Gels: A Comparative Study.

BACKGROUND: Adding lidocaine to hyaluronic acid (HA)-based gels appeared to modify their rheological properties, in the view of the first author. OBJECTIVE: This paper sought to compare the rheological properties of three CE-marked and FDA-approved gels, administered with and without lidocaine, along with two other newly FDA-approved gels. METHODS: The tested gels were as follows: NASHA® Restylane® with and without lidocaine; CPM®; Belotero® Balance with and without lidocaine; 3-D Matrix®; Surgiderm® 30XP (without lidocaine) and Juvederm® Ultra 3- Juvederm® Ultra Plus XC (with lidocaine); Preserved Network® RHA®2 (with lidocaine); Vycross® Volbella® (with lidocaine). For rheological analyses, viscoelastic data were collected with plate-plate geometry of 25mm, temperature regulated by a Peltier-effect plate, and the following assessed: Strain sweep from 0.01% to 3000% strain at 1Hz over frequency sweep from 0.1 to 100 Hz. RESULTS: NASHA Restylane gels with and without lidocaine exhibited similar viscoelastic characteristics, with very similar tan δ values, but the elastic modulus G' proved significantly higher when the gel was injected with lidocaine vs without. 3D-Matrix Surgiderm 30XP gel without lidocaine and Juvederm Ultra 3 with lidocaine exhibited similar viscoelastic characteristics, as well as tan δ values, yet the elastic modulus G' of Surgiderm 30XP proved significantly higher than that of Juvederm Ultra 3-Juvederm Ultra Plus XC. CPM Belotero Balance gels with and without lidocaine exhibited similar G' and G'' values. tan δ was somewhat higher when the gel was administered without lidocaine. VYCROSS Volbella gel exhibited a higher elastic modulus G' than the other Allergan gels, roughly nearing the NASHA gel values. Preserved Network RHA 2 gel exhibited values that were close to its partially cohesive "competitors", except for Vycross. CONCLUSION: Adding lidocaine to HA gels does modify their rheological properties yet this, to a variable extent depending on the product. J Drugs Dermatol. 2018;17(9):948-954.