Do You Know? - 04

Do You Know?

Vitamin C and Potassium Permanganate

Ever heard of doctor prescribing you with potassium permanganate wash when there's a superficial wound on your skin?

Potassium permanganate, also known as potassium manganate(VII), KMnO4 is a strong oxidizing agent which can be effectively used as a disinfectant.

It can be used as bath, wet compression, soak or wash. However, using potassium permanganate comes with a con. It may leave your skin, nails or clothing with a light brown stain.

This can be unpleasant to look at for some people. So here comes the saviour ------ Vitamin C.

To remove the stain, simply grab a vitamin C tablet, damp it with some water and then rub it gently on the stain. And ta-daaaaa, the stain will magically disappear.

So why does it works with vitamin C?

A redox reaction occurs.

Potassium permanganate acts as strong oxidizing agent.

Whereas vitamin C plays a role as a reducing agent. 

Vitamin C is oxidized in this reaction. The permanganate is reduced to MnO2 ions which is brown in color. 

Yet, at this point, the reaction has not ended. 

The liberalized manganese dioxide is then chelated with vitamin C to form complexes and prevents it from precipitating. Thus, the brown stain turns clear.

So, what can we do as a pharmacist regarding this topic?

Always remember to advise patient to grab some vitamin C whenever they're prescribed with potassium permanganate wash !