[Willway]

Hi,

I am trying to develop a handwash formulation using a nonionic surfactant. The main problem faced is that when we rinse my hands after using the formulation, the foam does not gets washed. It keeps on re-generating many times even when we keep washing the hands with fresh water.

Can anyone let me know as to what chemical needs to be added in the formulation to remove the leftover surfactant form the skin. 

[eugenedakin]

Hello Willway,

I suggest that you change or dramatially decrease the concentration of surfactant.  There are MANY types of surfactants that are non-foaming, slightly foaming, highly foaming for your application. 

There are also many types of surfactants that are great at removing dirt/oil/clay, etc.

The type of surfactant that you select will need to be tested by yourself to ensure that it has the right foaming-tendency that you are trying to acheive.

I wish you the best,

Eugene

[Willway]

Hello Willway,

I suggest that you change or dramatially decrease the concentration of surfactant.  There are MANY types of surfactants that are non-foaming, slightly foaming, highly foaming for your application. 

There are also many types of surfactants that are great at removing dirt/oil/clay, etc.

The type of surfactant that you select will need to be tested by yourself to ensure that it has the right foaming-tendency that you are trying to acheive.

I wish you the best,

Eugene

Hi Eugene,

Thank you for the suggestion.

Actually, I am using Nonyl Phenol as the surfactant and would like to prepare a surgical scrub using chlorhexidine gluconate. As you suggested, I have tried reducing the surfactant concentration to as low as 2% but still there is re-foaming. I assume that there should be some chemical(s) that needs to be added to the formulation to take care of this regenerative foam. Do you have any idea?

Regards,
Willway 

[eugenedakin]

Hi Willway,

It is interesting that you are using low-foam nonyl phenol ethoxylate as your emulsifier and you are having foaming issues.  Yes, you are right, you have a few options for lowering the foam further: 1) you can add a 'moisturizer' in the form of a non-allergenic oil, 2) you can use a defoamer, and/or 3) you can use an antifoamer.

Adding an oil reduces the foaming tendency (depending on the type of oil, it can act as both an antifoamer and defoamer)

Defoamers lower the foam that has already formed.  There are some different chemicals (typically based on the Si molecule) that are available to you.

Antifoams prevent the foam from forming in the first place, and are present in quite a varitey of forms, prices and quantities.

You have quite a few options.

I hope this helps you out. 

Sincerely,

Eugene