OBJECTIVE: Although an ascorbic acid-loaded dissolving microneedle patch has been developed to improve anti-wrinkle effects, an efficacy evaluation with a control group has not yet been performed. In this study, the anti-wrinkle effect of an ascorbic acidloaded dissolving microneedle patch was evaluated in a doubleblind clinical study with a control group. In addition, a cumulative skin irritation and sensitization potential of the ascorbic acid-loaded dissolving microneedle patch was performed. METHODS: Twenty-three subjects were selected for anti-wrinkle effect evaluation in a double-blind clinical study. Subjects were divided into two groups. Group I subjects applied an ascorbic acidloaded dissolving microneedle patch on a crow's feet area on the left side of the face and a control sample on a crow's feet area on the right side of the face every 4 days. Group II subjects placed the same patches on opposite sides of the face. Global Photodamage Score and skin replica analysis were conducted by visual inspection and skin visiometer, respectively. A skin irritation and sensitization assessment was performed on 51 subjects using the modified Shelanski & Shelanski procedure. Cumulative skin irritation potential and skin sensitization of the ascorbic acid-loaded dissolving microneedle patch and control sample were evaluated. RESULTS: Skin treated with the ascorbic acid-loaded dissolving microneedle patch showed a statistically significant improvement in both the Global Photodamage Score and visiometer R values (P < 0.05) compared with the control sample. The R2 value (maximum roughness), in particular, showed a highly significant improvement (P < 0.01). The skin irritation and sensitization assessment demonstrated that the ascorbic acid-loaded dissolving microneedle patch did not induce any cumulative skin irritation potential or skin sensitization. CONCLUSIONS: An ascorbic acid-loaded dissolving microneedle patch produced a significant anti-wrinkle effect without skin irritation and sensitization problems. This cosmetic dissolving microneedle patch can be used efficiently in the anti-wrinkle cosmetic field with patient convenience. R esum e OBJECTIF: Bien que le patch de microaiguilles a dissolution automatique charg e d'acide ascorbique ait et e d evelopp e pour am eliorer les effets anti-rides, une evaluation de l'efficacit e avec un groupe de contrôle n'a pas encore et e effectu ee. Dans cette etude, l'effet antirides d'un patch a microaiguilles a dissolution automatique charg e d'acide ascorbique a et e evalu e dans une etude clinique en double aveugle avec un groupe de contrôle. En outre, l'irritation de la peau et le potentiel de sensibilisation cumul es du patch de microaiguilles a dissolution automatique charg e d'acide ascorbique a et e effectu ee. M ETHODES: Vingt-trois sujets ont et e s electionn es pour l' evaluation de l'effet anti-rides dans une etude clinique en double aveugle. Les sujets ont et e divis es en deux groupes. Les sujets du Groupe 1 ont appliqu e un patch de microaiguilles a dissolution ...

This study established the safety criteria for irritation in the cosmetics field.

There are previous studies of ageing hair and scalp in Caucasians and some Asians, such as Koreans and Japanese. However, the characteristics of scalp and hair have not yet been studied in Chinese, the largest population in the world, especially in terms of ageing. The purpose of this study is to investigate ageing features in Chinese women's hair and scalp. Methods: In total, 1343 women in China aged 20 to 65 participated in this research. Hair density and diameter were measured and analysed with Folliscope®. Hair color and scalp conditions such as dandruff and erythema were evaluated through microscopic images. Measuring equipment was also used to detect scalp water content, barrier function and sebum secretion. Results: Hair density decreased gradually with ageing, while hair diameter peaked at 40s. The color of hair became bright with ageing because of gray hair and color fading. The degree of scalp sebum and dandruff was higher at younger ages. Interestingly, scalp erythema became more severe with ageing. Conclusion: This study shows the physical and physiological changes of Chinese women's hair and scalp. Most aging features (hair diameter, scalpsebum contents, dandruff and erythema) were noticeable in their 40s, but hair density began to decline in their 30s. This first study of aging hair and scalp in Chinese women would be helpful for understanding the ageing phenomenon and development of hair and scalp care products.