A Comparative In Vivo Study on Three Treatment Approaches to Applying Topical Botulinum Toxin A for Crow's Feet.

Yan Cao,Bing-Rong Zhou,Dan Luo,Sheng-Hua Guo,Jian-Ping Yang,Hong-Qin Chang,Jie Zhu,Xiao-Gang Zhu

doi:10.1155/2018/6235742

Abstract

Objective To evaluate the efficacy and safety of three treatment approaches to applying Botulinum Toxin Type A (BoNTA) for crow's Feet. Methods Thirty female subjects with moderate-to-severe crow's feet were included in this comparative in vivo study. They were randomly divided into three groups, including the local intramuscular, intradermal microdroplet injection, and nanomicroneedle delivered with BoNTA therapy group. After one session, evaluations were done at the time points of weeks one, four, and twelve after the treatment. The assessments included subjective satisfaction, blinded clinical assessment, and the biophysical parameters (skin collagen content, elasticity, hydration, and sebum contents). Results For dynamic wrinkles, intramuscular injection and intradermal microdroplets injection were more effective than nanomicroneedles. For static wrinkles, nanomicroneedles and intradermal microdroplets injection were more effective. However, the intramuscular injection had no significant effect on static wrinkles. At one week and four weeks after the treatment, the skin elasticity, collagen content, and hydration of nanomicroneedle group and intradermal microdroplet group increased more significantly than those of the intramuscular injection group; at twelve weeks after the treatment, the skin elasticity, collagen content, and hydration of intradermal microdroplet group were higher than those of other two groups. However we observed no statistically significant difference in sebum content between the three groups before and after the treatment. Conclusion BoNTA delivered through nanomicroneedles and intradermal microdroplets injection can effectively treat crow's feet. This trial is registered with [2016]KY018-01, registered 16 Feb 2016.

Highlights

The periorbital region is an area most vulnerable to aging, usually attacked by crow’s feet or lateral canthal lines
Botulinum Toxin Type A (BoNTA) is a neurotoxin protein secreted by clostridium botulinum, which is an anaerobic, Gram-positive bacterium
When the crow’s feet severity was assessed in a static condition, a statistically significant difference was detected from baseline to one, four, or twelve weeks after the treatment on both the nanomicroneedle group and the intradermal microdroplet group; no statistically significant difference was detected on the intramuscular injection group before and after treatment

Summary

Introduction

The periorbital region is an area most vulnerable to aging, usually attacked by crow’s feet or lateral canthal lines. Botulinum Toxin Type A (BoNTA) is a neurotoxin protein secreted by clostridium botulinum, which is an anaerobic, Gram-positive bacterium. It blocks the transmission of nerve impulses to the targeted muscle by selectively preventing the release of the neurotransmitter acetylcholine at the neuromuscular junction, a process that can temporarily prevent muscle contraction [5]. The ability of BoNTA to alleviate crow’s feet was first described in 1993 [6]. Since that time, it has been widely used in the cosmetic field to reduce wrinkles and rejuvenate the skin [7].

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