What is Merbromin?

Merbromin is an antiseptic used in cases of minor cuts and scrapes. It is also used in experimental biology to stain biological samples. It is an organo-mercuric disodium salt compound and hence is also marketed as mercurochrome (highlighting its capability to stain and a compound containing mercury), merbromine, mercurocol, sodium mercurescin, asceptichrome, supercrome, brocasept and cinfacromin. Although it is readily available in most countries because of its mercury content it is no longer sold in Switzerland, United States, France, Iran, Germany, Brazil, and Australia. 

The Merbromin Solution

Merbromin or merbromin solution is widely marketed as mercurochrome, where the suffix “mercuro” is for its mercury content and “chrome” is for its colouring properties. The merbromin solution is generally used even as an over-the-counter antiseptic solution, in which it is typically present at 2% concentration dissolved in ethyl alcohol (tincture) or water (aqueous). The ethyl alcohol solution also works as an inhibitor for the growth of microorganisms or infectious agents that would otherwise occur near the cut or scrape sites leading to it being one of the easily affordable antiseptics as the merbromin solution price is quite low and can be taken over the counter easily. 

Merbromin was discovered for its antiseptic properties by physician Hugh H. Young at the John Hopkins Hospital in 1918. The principal reason that merbromin uses mercury for disinfection is that it disrupts the metabolism of a microorganism and kills it. Later on, the antiseptic utility of the merbromin solution became so popular that it was used for all types of minor injuries and so common in day-to-day life as the first approach solution to treat schoolyard injuries in kids as well. Until 1998, it fell under the category of “generally recognised as safe” drugs or solutions classified for the general purpose by the FDA. But because of its mercury content and on the citation that it can lead to mercury poisoning, in 1998, FDA reclassified it under the “untested” category and since then the distribution was halted at least of the general purpose use of merbromin solution. This was followed by a halt in sales in Brazil (2001), Germany (2003), and France (2006). But it is readily available in most other countries.

Merbromin Synthesis

For the synthesis of merbromin, dibromofluorescein is combined with mercuric acetate and sodium hydroxide. Another way of synthesizing merbromin is by the action of mercuric acetate only on or in combination with sodium dibromofluorescein. Its prominent chemical properties include its anionic character which can be understood from the structure given below:

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Because of the anionic character of merbromin, it cannot be mixed with a majority of alkaloid salts and most local anaesthetics as they are acidic in nature and such mixing will result in dangerous exothermic reactions releasing toxic gases or aggravating a non-fatal injury into a serious one. Therefore, it is available in the market in a mixture of ethyl alcohol and aqueous water. 

Merbromin Uses

The widely accepted and best-known merbromin solution uses is an antiseptic for the treatment of minor wounds, burns, and scratches. Due to similar utilities, it is also used in the antisepsis of the umbilical cord and the antisepsis of the wounds with the inhibited scar formation, such as neuropathic ulcers and diabetic foot sores. Merbromin is also known for the staining of biological samples. When it is applied to a wound, the skin is stained with a distinctive carmine red colour. The stain persists for up to two weeks and is removed by repeated washings. Another common merbromin solution uses includes its activity on infections or toenails because of the permanence and lethality to bacteria. 

Scientifically, merbromin is also used in experimentation for the staining of biological samples. It is used as a biological dye for marking the tissue margins. In order to detect metal fractures, merbromin solution uses include its use as a metal dye in industrial dye penetrant inspection. 

FAQs (Frequently Asked Questions)

1. What is Merbromin Used For?

Ans: Merbromin is one of the most commonly used antiseptics. It is used as an antiseptic for the prevention of infection arising due to small cuts, abrasions and scrapes. It is commonly marketed as mercurochrome because of its colour and staining properties as well. It was one of the first in a series of chemical compounds to utilise mercury as a disinfectant as it renders a microorganism ineffective by disrupting the metabolism of a microorganism. It is so commonly used that it is also used to treat schoolyard injuries. 

2. Why is Mercurochrome Banned?

Ans: Mercurochrome is the marketed name of a chemical compound named merbromin. It is widely known and used for antiseptic properties and is commonly used for the treatment of minor cuts and scrapes. The main component of mercurochrome or mercurochrome is mercury. Previously in the United States, it was used as a generally regarded safe drug/solution. But in 1998, owing to the risk of leading mercury poisoning, its distribution for general use was halted by the FDA in the United States. Following the suit, it also got banned in the countries of Germany, France, Brazil, Switzerland, etc. In the rest of the countries of the world, it is widely used as an antiseptic and is commonly found in household first aid kits. 

3. What are the Uses of Mercurochrome in the Scientific Field?

Ans: Mercurochrome had been widely used as an antiseptic across the world until its production for normal use was halted by a number of nations in the 2000s owing to the risk of mercury poisoning because of the presence of mercury as its primary content. Apart from that, it is also known for its staining properties and is used in biological experiments to stain and mark tissue margins which can be later observed as distinctive carmine red colour. It is also used as a metal dye in industrial applications to identify metal cracks.