Formulation Advice for Topical Ointment Containing Keratolytics
I suffer from a very rare skin condition called Pityriasis Rubra Pilaris. It is characterized by keratoderma and psoriasis-like scaling. Unfortunately since it is so rare (approx. 1 in 400,000), research and development for treatment options is very sparse.
A Dermatologist who has worked extensively with such cases (Dr. Andrew Griffiths) advises in this presentation (apologies for the poorly formatted PDF, I am not the author):
that a topical treatment containing “keratolytics” is helpful (page 27).
Screenshot of the page here:
The formula is given as follows:
* Urea 5%
* Salicylic acid 5%
* Propylene glycol 20%
* Liquid paraffin 20%
* Emulsifying ointment to 100%
It is a pretty straight forward formula, however I would appreciate someone with the proper background in formulation to give their input on creating this ointment.
I have some basic background using very simple formulas such as
* beeswax, shea butter, mineral oil, and petrolatum with phenonip preservative
* oil-in-water with petrolatum, mineral oil, emulsifying wax NF (cetearyl alcohol and polysorbate 80), water, glycerin, beeswax, etc., with germaben II as preservative
My take on creating the “keratolytic” ointment would be first:
* find appropriate source for urea and salicylic acid
* evaluate possible safety concerns in handling above ingredients
* determine if a preservative is required and if so which one and at which concentration
* determine what is meant by “emulsifying ointment”
His background is most likely from the pharmaceutics and compounding perspective and the ’emulsifying ointment’ would be one of these bases:
I am thinking that using aquaphor or a similar pre-made o/w base could be appropriate.
If anyone is able to comment on my approach I would be appreciative.