Efficacy and Tolerability of Hybrid Complexes of High- and Low-Molecular-Weight Hyaluronan Intradermal Injections for the Treatment of Skin Roughness and Laxity of the Neck

Abstract

This study aimed to evaluate the efficacy of a well-characterized formulation of hyaluronic acid (HA), Profhilo®, in the treatment of roughness and laxity of the neck skin. The study was performed on 25 subjects ranging in age from 40 to 65 years. Two injections of the studied product at 30-day intervals were performed, with evaluations conducted 1 and 4 months after the first injection. The efficacy was determined by clinical and multilevel instrumental evaluations. In addition, at the end of the study, the subjects completed a questionnaire related to the efficacy and tolerability of the product. The studied product was shown to induce a clear and statistically significant improvement in the skin of the neck in all the subjects, with concordant results between the clinical, instrumental, and subjects' evaluations. The positive effects, present after the first injection, were further increased in the second and last evaluation. Notably, the product was reported to have a very high tolerability by both clinicians and subjects. In conclusion, two injections of the studied product safely induced skin amelioration in subjects with mild to moderate neck skin roughness and laxity.

Figure 1

Schematic representation of the 10 injection points used in this study.

Figure 2

IBSA Neck laxity scale.

Figure 3

Visual score (a) and clinical score change relative to baseline (b) for skin neck roughness and laxity. ^∗p < 0.05 vs. T0 (Holm-Sidak adjusted Wilcoxon signed rank test).

Figure 4

Representative photographic documentation obtained at baseline, T1 and T2.

Figure 5

Skin density was determined through profilometric parameters. Average roughness (a), total height (b) and maximum depth (c) were determined at T0, T1 and T2. The percentage of reduction at T1 and T2 vs. T0 is reported in each bar ^∗p < 0.05 vs. T0 (Holm-Sidak adjusted t test).

Figure 6

Superficial (a) and deep ((b), 0.5 mm, (c) 1.5 mm) skin layer hydration was determined at T0, T1 and T2. The percent increase at T1 and T2 vs. T0 is reported in each bar ^∗p < 0.05 vs. T0 (Holm-Sidak adjusted t test).

Figure 7

Plastoelasticity in the neck determined at T0, T1 and T2. The four parameters (Ue, Uf, Uv and Ur) determined with this technique are shown. The variations at T1 and T2 vs. T0 are reported in each bar, where ^∗p < 0.05 vs. T0 (Holm-Sidak adjusted Wilcoxon signed rank test).