Physical properties of a novel small‐particle hyaluronic acid filler: In vitro, in vivo, and clinical studies

Summary Background Infraorbital region is one of the most important regions that show the signs of aging. In recent years, hyaluronic acid ( HA ) fillers have been used to correct this region for esthetic treatments. Although HA fillers with various physical properties are used, limited research has been performed to compare their efficacy. Objective We aimed to compare three HA fillers to determine which is the most appropriate filler for the correction of the infraorbital region and evaluate the correction of such by performing a clinical test using CLEVIEL Fine. Methods We performed in vitro and in vivo tests using one new HA filler and two other commercial HA fillers. We compared the rheological properties, resistance to degradation, and in vivo duration test results of the three fillers. Nine patients participated in the clinical test using CLEVIEL Fine for 24 weeks. Results CLEVIEL Fine showed good rheological and physical characteristics for the infraorbital region. It had a low elasticity and cohesiveness, low incidence of postinjection swelling, high tanδ, narrow particle distribution, and small particle size. Further, it showed better resistance to the enzymes and radicals in the in vitro test than the other two HA fillers and a similar duration in the mouse test. In the clinical test, all patients showed good elasticity and hydration in the infraorbital region for 24 weeks. Conclusions CLEVIEL Fine was proven to be safe and effective based on the in vitro, in vivo, and clinical study results.