轻粉

English text reference: Chinese Pharmacopoeia (2020 Edition)
中文文本参考：《中国药典（2020年版）》

Overview 概述

Calomel is the chloride of mercury (Hg2Cl2).
本品为氯化亚汞（Hg2Cl2）。

Description 性状

Calomel occurs as white, lustrous, scaly or snowflake-like crystals, or as crystalline powder. It darkens slowly on exposure to light. Odour, slight.
本品为白色有光泽的鳞片状或雪花状结晶，或结晶性粉末；遇光颜色缓缓变暗。气微。

Identification 鉴别

(1) When tested with calcium hydroxide solution, ammonia solution or sodium hydroxide solution, it turns black.
（1）本品遇氢氧化钙试液、氨试液或氢氧化钠试液，即变成黑色。

(2) Take the product, mix it with an equal amount of anhydrous sodium carbonate, place it in a dry test tube, heat it, and metallic mercury is decomposed and condensed on the wall of the test tube. Dissolve the residue remaining in the tube in dilute nitric acid, filter, and the filtrate shows the identification reaction of chloride (General Rule 0301).
（2）取本品，加等量的无水碳酸钠，混合后，置干燥试管中，加热，即分解析出金属汞，凝集在试管壁上，管中遗留的残渣加稀硝酸溶解后，滤过，滤液显氯化物（通则0301）的鉴别反应。

Examination 检查

Mercury 升汞

Take 2 g of the product, add 20 ml of ether, shake for 5 minutes, filter, evaporate the filtrate to dryness, dissolve the residue in 10 ml of water with 2 drops of dilute nitric acid, and examine according to the method for chloride (General Rule 0801). If turbidity occurs, compare it with a control solution prepared in the same manner using 7 ml of standard sodium chloride solution, and it should not be more turbid.
取本品2g，加乙醚20ml，振摇5分钟后，滤过，滤液挥去乙醚，残渣加水10ml与稀硝酸2滴溶解后，照氯化物检查法（通则0801）检查，如发生浑浊，与标准氯化钠溶液7ml用同一方法制成的对照液比较，不得更浓。

Mercury beads 汞珠

Take about 1 g of the product, spread it on white paper, and examine it with a magnifying glass. There should be no mercury beads.
取本品约1g，平铺于白纸上，用扩大镜检视，不应有汞珠存在。

Residue on ignition 炽灼残渣

Not more than 0.1% (General Rule 0841).
不得过0.1%（通则0841）。

Assay 含量测定

The sample, about 0.5 g, is accurately weighed, placed in an iodine flask, and 10 ml of water is added. The mixture is shaken well, and then 50 ml of iodine titration solution (0.05 mol/L) is accurately added. The flask is stoppered, and the mixture is vigorously shaken until most of the sample is dissolved. Then, 8 ml of potassium iodide solution (5→10) is added, the flask is stoppered, and the mixture is vigorously shaken until completely dissolved. The solution is titrated with sodium thiosulfate titration solution (0.1 mol/L) to near the end-point. Starch indicator solution is added, and the titration is continued until the blue colour disappears. Each 1 ml of iodine titration solution (0.05 mol/L) is equivalent to 23.61 mg of mercury chloride (Hg2Cl2).
取本品约0.5g，精密称定，置碘瓶中，加水10ml，摇匀，再精密加碘滴定液（0.05mol/L）50ml，密塞，强力振摇至供试品大部分溶解后，再加入碘化钾溶液（5→10）8ml，密塞，强力振摇至完全溶解，用硫代硫酸钠滴定液（0.1mol/L）滴定，至近终点时，加淀粉指示液，继续滴定至蓝色消失。每1ml碘滴定液（0.05mol/L）相当于23.61mg的氯化亚汞（Hg2Cl2）。

The content of mercury chloride (Hg2Cl2) in the product shall not be less than 99.0%.
本品含氯化亚汞（Hg2Cl2）不得少于99.0%。

Property 性

Cold.
寒。

Toxicity 毒性

Toxic.
有毒。

Flavor 味

Pungent.
辛。

Meridian tropism 归经

Large Intestine and Small Intestine meridians.
归大肠、小肠经。

Actions 功能

To kill parasites, counteract toxicity, promote wound healing when used externally; to resolve phlegm, eliminate accumulation, promote diuresis, and facilitate bowel movement when taken internally.
外用杀虫，攻毒，敛疮；内服祛痰消积，逐水通便。

Indications 主治

It is used externally for scabies, ringworm, poliomyelitis, syphilis, sores and eczema; internally for phlegm and saliva stagnation, oedema and swelling, and bowel problems.
外治用于疥疮，顽癣，臁疮，梅毒，疮疡，湿疹；内服用于痰涎积滞，水肿膨胀，二便不利。

Dosage 用量

Appropriate amount for external use; 0.1～0.2g each time for internal use, 1～2 times a day.
外用适量；内服每次0.1～0.2g，一日1～2次。

Administration 用法

Ground and mixed with the affected area; more into the pill or capsule service, gargling after service.
研末掺敷患处；多入丸剂或装胶囊服，服后漱口。

Precautions 注意

This product is toxic and should not be taken in excessive amounts. It should be used with caution when taken internally, and it is contraindicated in pregnant women.
本品有毒，不可过量；内服慎用；孕妇禁服。

Storage 贮藏

Store in a light-resistant, airtight container in a dry place.
遮光，密闭，置干燥处。

轻粉

Text reference: Chinese Pharmacopoeia (2015 Edition)
文本参考：《中国药典（2015年版）》

Overview 概述

Calomel is a mercurous chloride (Hg2Cl2).
本品为氯化亚汞（Hg2Cl2）。

Description 性状

White, lustrous, scaly or snow-flake like crystals, or a crystalline powder. Gradually darkened on exposing to light. Odour, slight; almost tasteless.
本品为白色有光泽的鱗片状或雪花状结晶，或结晶性粉末；遇光颜色缓缓变暗。气微。

Identification 鉴别

（2）取本品，加等量的无水碳酸钠，混合后，置干燥试管中，加热，即分解析出金属汞，凝集在试管壁上，管中遗留的残渣加稀硝酸溶解后，滤过，滤液显氯化物（通则0301）的鉴别反应。
（1）本品遇氢氧化钙试液、氨试液或氢氧化钠试液，即变成黑色。

Examination 检查

Mercuric chloride 升汞

Shake 2 g of the drug in 20 ml of ether for 5 minutes, filter, allow to stand and expel the ether. Dissolve the residue in 10 ml of water and 2 drops of dilute nitric acid TS, carry out the limit test for chlorides <0801>. Any turbidity produced is not more intense than a reference solution prepared with 7 ml of standard solution of sodium chloride.
取本品2g，加乙醚20ml，振摇5分钟后，滤过，滤液挥去乙醚，残渣加水10ml与稀硝酸2滴溶解后，照氯化物检查法（通则0801）检查，如发生浑浊，与标准氯化钠溶液7ml用同一方法制成的对照液比较，不得更浓。

Mercury globule 汞珠

Spread 1 g of the drug on a piece of white paper, examine under a lens, no mercury globule should be found.
取本品约1g，平铺于白纸上，用扩大镜检视，不应有汞珠存在。

Residue on ignition 炽灼残渣

Not more than 0.1 per cent <0841>.
不得过0.1%（通则0841）。

Assay 含量测定

To about 0.5 g of the powder, accurately weighed in a stopper flask, add 10 ml of water, shake well,add 50 ml of iodine (0.1 mol/L)VS, accurately measured, stopper tightly, shake vigorously until most of the powder dissolved, add 8 ml of potassium iodide solution (5→10), stopper tightly, shake vigorously to dissolve completely, titrate with sodium thiosulfate (0.1 mol/L) VS towards the end of titration, add starch IS,continue to titrate until the blue colour disappeared. Each ml of iodine (0.1 mol/L) VS is equivalent to 23.61 mg of HgeCl. It contains not less than 99.0 per cent of mercurous chloride (Hg2Cl2)
取本品约0.5g，精密称定，置碘瓶中，加水10ml，摇匀，再精密加碘滴定液（0.05mol/L）50ml，密塞，强力振摇至供试品大部分溶解后，再加入碘化钾溶液（5→10）8ml，密塞，强力振摇至完全溶解，用硫代硫酸钠滴定液（0.1mol/L）滴定，至近终点时，加淀粉指示液，继续滴定至蓝色消失。每1ml碘滴定液（0.05mol/L）相当于23.61mg的氯化亚汞（Hg2Cl2）。

Property and Flavor 性味与归经

Cold; pungent； toxic. Meridian tropism: Large intestine and small intestine meridians.
辛，寒；有毒。归大肠、小肠经。

Actions and Indications 功能与主治

Topical application: To kill worms, conteract toxic substances, and promote wound healing；Oral administration: To dispel phlegm, relieve accumulation, expel water and open the bowels.
外用杀虫，攻毒，敛疮；内服祛痰消积，逐水通便。

Indications 主治

Topical application: scabies, stubborn tinea, shank sore, syphilis, sore and ulcer, and eczema; Oral administration: excessive phlegm and saliva, edema,tympanites, inhibited defecation and urination.
外治用于疥疮，顽癣，臁疮，梅毒，疮疡，湿疹；内服用于痰涎积滞，水肿臌胀，二便不利。

Administration and dosage 用法与用量

Appropriate amount for topical application, ground into powder for applyment; Oral administration: 0.1-0.2 g per time, 1-2 a day, usually used in pills or capsules, gargling after oral administration.
外用适量，研末掺敷患处。内服每次0.1～0.2g，一日1～2次，多入丸剂或装胶囊服，服后漱口。

Precautions and Warnings 注意

Poisonous, avoid overdosage. Be cautious for oral administration. Contraindicated for pregnant woman.
本品有毒，不可过量；内服慎用；孕妇禁服。

Storage 贮藏

Preserve in a well closed container, and protect from light and stored in a dry place.
遮光，密闭，置干燥处。