Calomelas and its preparations: Paradigms of traditional Chinese external medicine

Traditionally, Calomelas and its preparations have been employed in traditional Chinese medicine (TCM) for the management of scabies and ulcers, exhibiting empirically validated efficacy in wound management protocols, with persistent contemporary utilization. Nevertheless, significant concerns regarding its mercury composition have prompted modern scrutiny. Crucially, a rigorous systematic evaluation of Calomelas and its preparations was still lacking in the existing literature, which hindered their evidence-based application and potential advancement.

This review aims to clarify the medicinal benefits and toxicity of Calomelas and its preparations, supporting the development of modern treatments for refractory skin ulcers while promoting the safe and rational integration of Calomelas-containing preparations into dermatological practice.

Data on Calomelas and its preparations were systematically collated from scientific databases, including PubMed, Google Scholar, ACS Publications, Web of Science, ScienceDirect, CNKI, and WANGFANG.

Calomelas, a mercury-based compound utilized in TCM since the Tang dynasty, has exhibited pronounced therapeutic efficacy in the management of various refractory wound conditions. Several Calomelas-containing preparations, such as Shengji Yuhong Ointment, Babao Pill, Baodu Shengji Powder, Taiyi Ointment, and Calomelas Powder, are routinely utilized in clinical practice for the treatment of diverse skin ulcers and stubborn wounds, including diabetic foot ulcers, postoperative impairments, pressure injuries, and burn wounds. The pharmacological basis of these therapeutic effects relies on their biological activity properties, including antibacterial, anti-inflammatory, antioxidant, pro-angiogenic, and pro-gliogenic activities. Despite ongoing safety concerns related to the inherent toxicity of mercury, Calomelas and its preparations exhibited an acceptable safety profile when administered in accordance with established clinical protocols.

Calomelas and its preparations are supported by clinical validation and modern pharmacological research, confirming their definite therapeutic efficacy and controllable safety profile. These findings highlight their significant clinical value and broad application prospects in the surgical practice of TCM.