Physicochemical Properties of Injectable Hyaluronic Acid: Skin Quality Boosters

Abstract

In addition to clinical research on the efficacy and compatibility of injectable hyaluronic acid (HA) based fillers, ample in vitro research on the physicochemical properties of these materials is published. Different HA‐based product ranges are also available as skin quality boosters (SQBs) to improve skin quality. The aim of this study is to investigate the physicochemical properties of specific HAs for improving skin quality, as, to the best of the authors' knowledge, no data is published on this topic to date. This paper may provide a better understanding of clinical performance and differentiation between these SQBs. Five HA injectable hydrogels (Belotero Revive, Juvederm Volite, Restylane Skinbooster Vital, Viscoderm Hydrobooster, and Profilho) from the SQB product ranges of different companies and manufacturing technologies are investigated for their extrusion force, swelling degree, rheological performance, and cohesivity. There are significant differences in extrusion force, swelling degree, rheological performance, and cohesivity between the assessed SQBs. HA concentration (mg mL−1) exhibits statistically significant positive correlations with extrusion force, swelling degree, tan delta, and cohesivity. This study provides a physicochemical characterization of different SQBs and information to improve understanding of this type of product.

Approach to differentiate between hyaluronic acid skin quality boosters and fillers based on their physicochemical properties

“…G* (overall viscoelasticity) and G′ (gel stiffness and lifting capacity) values measured were similar to those reported by other authors 11,13,23 …”

“…The extrusion force indicates how difficult or easy it is to extrude the hydrogel from a syringe through a needle. As shown in previous studies, higher HA concentration, crosslinking, and viscoelastic behavior affect extrusion force 10,13,14,17,19 …”

“…Material properties of HA injectables have been utilized to assign HA gel properties to clinical indications and desired effects 3,7‐12,17,19,23 . Differences between technologies and physicochemical properties have already been demonstrated separately for volumizing filler products as well as for SQBs, but have never been compared 7‐9,12,13 …”

“…For each product, three measurements were performed for each experiment under standardized conditions. Experimental methods are the same as described previously 13 …”

“…For this purpose, photos were collected for each sample in an experiment with stained hydrogels. The experiment was performed, as reported elsewhere, 12 with a modified toluidine blue solution (10 µl, 0.1% w/w in PBS, pH 7.4) 7 and a 1 kg calibration weight for extrusion 13 …”