Over-the-counter anti-ageing topical agents and their ability to protect and repair photoaged skin

Current Insights into the Formulation and Delivery of Therapeutic and Cosmeceutical Agents for Aging Skin

“Successful aging” counters the traditional idea of aging as a disease and is increasingly equated with minimizing age signs on the skin, face, and body. From this stems the interest in preventative aesthetic dermatology that might help with the healthy aging of skin, help treat or prevent certain cutaneous disorders, such as skin cancer, and help delay skin aging by combining local and systemic methods of therapy, instrumental devices, and invasive procedures. This review will discuss the main mechanisms of skin aging and the potential mechanisms of action for commercial products already on the market, highlighting the issues related to the permeation of the skin from different classes of compounds, the site of action, and the techniques employed to overcome aging. The purpose is to give an overall perspective on the main challenges in formulation development, especially nanoparticle formulations, which aims to defeat or slow down skin aging, and to highlight new market segments, such as matrikines and matrikine-like peptides. In conclusion, by applying enabling technologies such as those delivery systems outlined here, existing agents can be repurposed or fine-tuned, and traditional but unproven treatments can be optimized for efficacious dosing and safety.

Use of Retinoids in Topical Antiaging Treatments: A Focused Review of Clinical Evidence for Conventional and Nanoformulations

Nowadays, numerous skincare routines are used to rejuvenate aging skin. Retinoids are one of the most popular ingredients used in antiaging treatments. Among the representatives of retinoids, tretinoin is considered the most effective agent with proven antiaging effects on the skin and can be found in formulations approved as medicines for topical treatment of acne, facial wrinkles, and hyperpigmentation. Other retinoids present in topical medicines are used for various indications, but only tazarotene is also approved as adjunctive agent for treatment of facial fine wrinkling and pigmentation. The most commonly used retinoids such as retinol, retinaldehyde, and retinyl palmitate are contained in cosmeceuticals regulated as cosmetics. Since clinical efficacy studies are not required for marketing cosmetic formulations, there are concerns about the efficacy of these retinoids. From a formulation perspective, retinoids pose a challenge to researchers as a result of their proven instability, low penetration, and potential for skin irritation. Therefore, novel delivery systems based on nanotechnology are being developed to overcome the limitations of conventional formulations and improve user compliance. In this review, the clinical evidence for retinoids in conventional and nanoformulations for topical antiaging treatments was evaluated. In addition, an overview of the comparison clinical trials between tretinoin and other retinoids is presented. In general, there is a lack of evidence from properly designed clinical trials to support the claimed efficacy of the most commonly used retinoids as antiaging agents in cosmeceuticals. Of the other retinoids contained in medicines, tazarotene and adapalene have clinically evaluated antiaging effects compared to tretinoin and may be considered as potential alternatives for antiaging treatments. The promising potential of retinoid nanoformulations requires a more comprehensive evaluation with additional studies to support the preliminary findings.

Transdermal nanotherapeutics: Panax quinquefolium polysaccharide nanoparticles attenuate UVB-induced skin cancer

Ultraviolet (UV) radiation is known to cause an imbalance of the endogenous antioxidant system leading to an increase in skin cancer. Panax quinquefolium (American ginseng) polysaccharides (GPS) can inhibit such an imbalance due to its anti-oxidative and anti-inflammatory properties. The aim of this study was to investigate the therapeutic effects of topical formulations containing GPS nanoparticles (NPs) to inhibit UVB induced oxidative damage and skin cancer. Photoaging was conducted under UVB irradiation with a dose of 300 mJ/cm2 on SKH1 hairless mice. The treatment groups (n = 5) were as follows: sham control, native GPS, GPS NPs and fluorescent labeled GPS NPs. To compare the photoprotective performance, the topical formulations were applied before and after UVB induction (pre-treatment and post-treatment), followed by sacrificing the animals. Then, skin and blood samples were collected, and inflammatory cytokines production was measured using ELISA. Compared to the sham control, GPS NPs pre-treated mice skin and blood samples exhibited a significant lowering in all cytokine production. In addition, skin histology analysis showed that pre-treatment of GPS NPs prevented epidermal damage and proliferation. The results support that topical formulation containing GPS NPs can inhibit UVB induced oxidative damage and skin cancer.

Microencapsulation of retinyl palmitate by melt dispersion for cosmetic application

Retinyl palmitate was encapsulated in wax matrix by melt dispersion for the purpose of economic and sustainable cosmeceutical formulation with minimum use of synthetic chemicals. We evaluated the effect of different process variables of microencapsulation by melt dispersion. In this study, a three level definitive screening design was applied, where the microcapsule properties were analysed through statistical analysis to understand the effect of four process variables: type of wax, theoretical loading capacity, surface concentration and stirring speed. Microparticles were characterised for size using image analysis; loading capacity and encapsulation efficiency using ultraviolet-visible spectroscopy; antioxidant activity through DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Melt dispersion method was effective to produce microcapsules with a spherical shape and mean size as small as 28 µm. The encapsulation efficiency ranged 60-80%. Theoretical loading capacity (p-value = 0.00232, significance level, α = 1%) and surfactant% (p = 0.0573, α = 10%) were found to be the most significant factors to control the actual loading capacity and size of microcapsules.

In vivo topical application of acetyl aspartic acid increases fibrillin-1 and collagen IV deposition leading to a significant improvement of skin firmness

OBJECTIVE

Acetyl aspartic acid (A-A-A) was discovered through gene array analysis with corresponding Cmap analysis. We found that A-A-A increased keratinocyte regeneration, inhibited dermal matrix metalloprotease (MMP) expression and relieved fibroblast stiffness through reduction of the fibroblast stiffness marker F-actin. Dermal absorption studies showed successful delivery to both the epidermal and dermal regions, and in-use trial demonstrated that 1% A-A-A was well tolerated. In this study, the aim was to investigate whether A-A-A could stimulate the synthesis of extracellular matrix supporting proteins in vivo and thereby improving the viscoelastic properties of human skin by conducting a dual histological and biophysical clinical study.

METHOD

Two separate double-blind vehicle-controlled in vivo studies were conducted using a 1% A-A-A containing oil-in-water (o/w) emulsion. In the histological study, 16 female volunteers (>55 years of age) exhibiting photodamaged skin on their forearm were included, investigating the effect of a 12-day treatment of A-A-A on collagen IV (COLIV) and fibrillin-1. In a subsequent pilot study, 0.1% retinol was used for comparison to A-A-A (1%). The biomechanical properties of the skin were assessed in a panel of 16 women (>45 years of age) using the standard Cutometer MPA580 after topical application of the test products for 28 days. The use of multiple suction enabled the assessment of F4, an area parameter specifically representing skin firmness.

RESULTS

Twelve-day topical application of 1% A-A-A significantly increased COLIV and fibrillin with 13% and 6%, respectively, compared to vehicle. 1% A-A-A and 0.1% retinol were found to significantly reduce F4 after 28 days of treatment by 15.8% and 14.7%, respectively, in the pilot Cutometer study. No significant difference was found between retinol and A-A-A. However, only A-A-A exhibited a significant effect vs. vehicle on skin firmness which indicated the incremental benefit of A-A-A as a skin-firming active ingredient.

CONCLUSION

In this study, we showed the in vivo efficacy of 1% A-A-A both on a protein level (fibrillin and collagen IV) and on a clinical end point, specifically skin firmness, providing proof that, acetyl aspartic acid has a strong potential as an anti-ageing 'cosmeceutical' ingredient answering the needs of our key consumer base.

Acetyl aspartic acid, a novel active ingredient, demonstrates potential to improve signs of skin ageing: from consumer need to clinical proof

BACKGROUND

The megatrend of population ageing is leading to a growing demand for "anti-ageing" treatments, especially to prevent or treat skin ageing. Facing an increasing offer, consumers are choosing more and more skin care products supported by a scientific rationale, active ingredients and clinical proof of efficacy.

OBJECTIVE

Considering consumer expectations, this research led to the discovery of acetyl aspartic acid (A-A-A), a novel active ingredient to improve sagging skin and loss of skin firmness.

RESULTS

This supplement is featuring seven manuscripts aiming at presenting the research and investigations from consumer insights, discovery of A-A-A, its in vitro activity confirmation, safety assessment, formulation and its dermal absorption to the clinical proof of efficacy, investigated through two pilots' double bind randomized and placebo controlled studies on photo-aged skin.

CONCLUSION

This extensive research enabled us to discover A-A-A, as an active ingredient with potential to repair sign of skin ageing and supported by clinical proof of efficacy. This active ingredient will be soon launched in a commercial innovative skin care range, delivering desirable anti-wrinkle and skin lifting benefits.