[Tom]

Glyceryl Stearate SE is Glyceryl Stearate with small amounts of Sodium Stearate making it a O/W-Emulsifier. But your formulation is already based on fatty acid soaps. So Glycerin Stearate will act as structurizer and co-Emulsifier - this is why i mentioned to try fatty alcohols like stearyl alcohol instead. Your emulsifier are the fatty acid soaps - for emulsifying the Octyldodecanol.

Modern shaving cream formulations are often formulated as “soap free”. This systems are formulated with synthetic surfactants in a lower pH-region and are claimed to be less irritating.

Are your batches stored @75°F (~RT)?

[Tom]

I would try 1-2% Glyceryl Stearate (start with 1%, but also try Cetyl or Stearyl Alcohol instead) and 2-5% Octyldodecanol. Also you can try other emollient instead of Octyldodecanol (Dimethicone and mineral oil are often used but you can add more natural oil too but concider the stability). As time permits you can try adding gelling agents to add structure in your formulation and play with the rheology, additionally you can improve stability and and more slip.

[Tom]

This is true when adding emollients in soaps and shampoos etc (but adding small amounts can improve your foam in this formulas as well). But formulating a shaving cream is more like formulating an emulsion with wash-active substances. Emollients (most common fatty acids etc) are essential ingredients to get slip and softening the shaving area.

[Tom]

Oh, never heard about that.. As MarkBroussard wrote, the longer glycols will be an option for you and you can try phenoxyethanol, too (or a combination)

[Tom]

There is no microbial grow possible in anhydrous formulations, so why precaution?

[Tom]

As a guarbet alcohol, octyldodecanol is one of the more polar emollients, its not that greasy.

[Tom]

Softisan 378

[Tom]

I think it is propylene glycol, because of piroctone olamine’s great solubility