Reduction of enlarged facial pore using ion-paired amino acid through enhancement in skin permeation and exfoliation: A placebo-controlled in vivo study

Evaluation of a Cosmetic Formulation Containing Arginine Glutamate in Patients with Burn Scars: A Pilot Study

Background: Patients with burn scars require effective treatments able to alleviate dry skin and persistent itching. Ion pairing has been employed in cosmetic formulations to enhance solubility in solvents and improve skin permeability. To evaluate the efficacy and safety of the cosmetic formula "RE:pair (arginine-glutamate ion pair)", we analyzed scar size, itching and pain, skin barrier function, scar scale evaluation, and satisfaction in our study participants. Methods: A total of 10 patients were recruited, and the formula was used twice a day for up to 4 weeks. Results: Itching was significantly alleviated after 4 weeks of treatment (95% CI = -0.11-1.71) compared to before application (95% CI = 2.11-4.68). Transepidermal water loss (TEWL) showed an 11% improvement after 4 weeks (95% CI = 3.43-8.83) compared to before application (95% CI = 3.93-9.88), and skin coreneum hydration (SCH) showed a significant 41% improvement after 4 weeks (95% CI = 43.01-62.38) compared to before application (95% CI = 20.94-40.65). Conclusions: Based on the confirmation that RE:pair improves skin barrier function and relieves itching, it is likely to be used as a topical treatment for burn scars pending evaluation in follow-up studies (IRB no. HG2023-016).

Enhancement of Exfoliating Effects through the Novel Cosmetic Ingredient Mandelic acid_Carnitine Ion-Pairing Complex

PURPOSE

This study aimed to develop a novel exfoliating material with high efficacy and low irritation by synthesizing the Mandelic acid_Carnitine ion pairing complex (M_C complex) and evaluating its exfoliating properties. Additionally, the study assessed the skin improvement effects of the M_C complex through clinical evaluations.

METHODS

The M_C complex was synthesized in a 1:1 molar ratio of Mandelic acid and Carnitine. Structural characterization was performed using dynamic light scattering and Fourier-transform infrared spectroscopy. Exfoliating efficacy was evaluated on porcine skin, and clinical assessments were conducted on human subjects to measure various skin improvement parameters.

RESULTS

The formation of the M_C complex was confirmed through particle size analysis, zeta-potential measurements, and FT-IR spectroscopy. The M_C complex demonstrated superior exfoliating efficacy compared to Mandelic acid alone, especially at pH 4.5. Clinical evaluations showed significant improvements in blackheads, whiteheads, pore volume, depth, density, count, and affected area, as well as skin texture. No adverse reactions were observed.

CONCLUSION

The M_C complex exhibits high exfoliating efficacy and minimal irritation, making it a promising cosmetic ingredient for improving skin health. These findings support its potential as a low-irritation exfoliating material under mildly acidic conditions, contributing to overall skin health enhancement.

Anti-acne activity of carnitine salicylate and magnolol through the regulation of exfoliation, lipogenesis, bacterial growth and inflammation

BACKGROUND

Salicylic acid has been used as an anti-acne agent with its comedolytic property and antimicrobial activity. However, there is a limit to use for leave-on cosmetics because of the transient skin irritation and low efficacy at neutral pH condition. We prepared a salicylic acid-based ionic pair with L -carnitine (we named, IP-BHA) overcoming the limitation of salicylic acid. We examined the effect of IP-BHA as well as the combination effect with magnolol, a bioactive organic lignan, in order to clarify their efficacy as anti-acne agents.

METHODS

After verifying the structure of IP-BHA, we confirmed anti-acne activities including the regulation of exfoliation, lipogenesis, bacterial growth, and inflammation with IP-BHA and/or magnolol.

RESULTS

The antibacterial activity of IP-BHA and magnolol was evaluated by determining the minimum antibacterial inhibitory concentration. Magnolol showed strong activity against Cutibacterium acnes, which was better than a medical antibiotic acne drug, clindamycin. The combined application with IP-BHA was more effective in antibacterial activity by 2.5 times. It was confirmed that testosterone-induced lipogenesis was significantly inhibited by treatment with IP-BHA and magnolol, while single treatment had no significant inhibitory effect. Interestingly, MMP-1 and VEGF were induced by C. acnes lysate in human keratinocytes. We found that these inflammatory molecules were completely inhibited by combined application of IP-BHA and magnolol. Through ex vivo test, the dose-dependent exfoliation effect of IP-BHA was confirmed at pH 5.5, and the synergic exfoliation effect was shown in the combined application of IP-BHA and magnolol. When topically applied, the emulsion containing IP-BHA and magnolol relieved the sodium dodecyl sulfate-induced erythema and improved inflamed acne with papule and pustule.

CONCLUSION

Our data demonstrate that the ionic paired salicylic acid with L -carnitine can overcome the limitations of salicylic acid at low concentration and natural skin pH. Based on the dual administration effects, we suggest that IP-BHA and magnolol may be the potential agent for acne by improving inflammatory skin condition.

The Effects of Arginine Glutamate (RE:pair) on Wound Healing and Skin Elasticity Improvement After CO2 Laser Irradiation

BACKGROUND

Glutamic acid is known to be effective for keratinocyte proliferation, but its dermatological application is limited due to its poor solubility in water and various solvents.

AIM

Here, the efficacy of the arginine glutamate ion pair (named as RE:pair) for recovering damaged skin and improving skin elasticity was investigated through the analysis of keratinocyte proliferation and collagen synthesis.

METHODS

Following the structural analysis of RE:pair using spectroscopic methods, a scratch assay, and Pro-Collagen I ELISA, skin tissue changes in wound-induced artificial skin, changes in wound area after laser wound induction, and the sensory evaluation of skin improvement were investigated.

RESULTS

As a result of scratch assay, wound recovery of 94.55±9.57% was confirmed at 10 ppm RE:pair treatment. When evaluation of expression efficacy of procollagen type I, it was found that the expression rate was increased by 32.47±5.62% compared to the control group. Further, the upregulation of the proliferation marker Ki-67 and filaggrin expression in the damage-induced artificial skin was verified. Clinically, the improvement was subjectively verified in terms of the reduction of the wound area, the restoration of the barrier, the improvement of skin elasticity, and through the sensory experience of skin improvement.

CONCLUSION

RE:pair shows a greater therapeutic effect than the individual effects of its constituent amino acids and those of the simple mixtures of these compounds. RE:pair exerts its therapeutic action by promoting the proliferation of keratinocytes and enhancing collagen synthesis in fibroblasts. Accordingly, it can be used throughout the cosmetic industry as an effective amino acid wound healing and skin elasticity improving material.