Home Cosmetic Science Talk Formulating Methyl and Propylparaben solubility

  • oldperry

    January 28, 2014 at 8:13 am

    These materials are both powders so the question doesn’t make sense.  If you are talking about aqueous solutions of the compounds, then yes, they are soluble.

  • mikebavington

    January 28, 2014 at 9:09 am

    Sorry. I meant to ask whether these preservatives are soluble in an aqueous solution of panthenol, with the panthenol at about 2 - 3%. So, based upon your answer, these preservatives would be. Thanks

    I know that formulators will often use propylene glycol to first dissolve the methyl and  propylparaben, but I thought that since I already have panthenol in my formula, I could avoid having to dissolve the preservatives in anything else, beforehand.
  • Bobzchemist

    January 28, 2014 at 9:13 am

    That’s not a lot of water to dissolve parabens into - you may get a slurry instead of a solution.

  • mikebavington

    January 28, 2014 at 10:40 am

    My formula has mostly water - greater than 90% - with about 3% DL panthenol. I will dissolve the panthenol in the water first and then add the preservatives afterwards.

    I will share some of my thoughts on preservatives for anyone who is reading this and might have similar questions to myself.
    I was going to use Potassium Sorbate because I have read favourable testing conclusions regarding its low level of skin sensitization. Potassium Sorbate has even tested favourably on mucous membranes inside the nose in regards to maintaing proper cilia function, and therefore, has been suggested as an alternative to Benzalkimonium Chloride in nasal solutions.  So, if it tests well inside the nose, I surmize that it would also be suitable for sensitive skin on the body. However, Potassium Sorbate seems to lack broad spectrum preservative effectiveness.
    I also considered Silver Citrate and Citric Acid - brand name Silveron 2400 - but was advised that it doesnt perform well when used with cellulose thickeners or other ingredients that carry a positive charge. I am using HEC as my emulsifier/thickener and because I am also using another ingredient which is cationic in nature, I ruled out the Silveron.
    I dont worry about some consumers’ anti-parabens mindset because my product is not going to be marketed to the segment of end-users that routinely look for alternatives to parabens. Although, from what I understand, parabens are found in nature to preserve berries and other things. so I guess they would qualify as an all-natural ingredient, in fact.  
    Preservatives are an important consideration for me because I want to avoid any costly contamination issues once my formula in sold throughout the market. Between liability issues and any recall that might happen from a contaminated product, I figure I would rather make 100% certain my product is safe from contamination. What I might lose in sales from using parabens will likely be less than what it would cost me to sell a contaminated product.
  • MakingSkincare

    January 28, 2014 at 10:59 am

    I would go with a preservative blend such as: 0.5% Phenoxyethanol, 0.3% Methylparaben and 0.2% Propylparaben plus a chelator, for example, disodium EDTA and design your packaging so it minimises contamination during use. 

  • mikebavington

    January 28, 2014 at 5:03 pm

    Wont Phenoxyehtanol be incompatible with my HEC?

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