Home Cosmetic Science Talk Formulating Spray-on scalp formulation

  • Spray-on scalp formulation

    Posted by Anonymous on January 27, 2020 at 8:30 am
    Hey everyone,
    I’m David. While I don’t have a chemistry background, I’ve always had a fascination with the composition of practical products like soaps, cleaners, shampoos, etc. I like to read the ingredients of the products I come across and learn about the components I haven’t yet encountered.
    I’m working on a topical product for androgenic alopecia based primarily on active botanical components. Given the challenge of applying liquids to the scalp, I think that a spray-on formulation (i.e. low viscosity in a spray bottle) would make this process easier. The gist of this product is an ethanolic extraction from botanicals which is designed for transdermal penetration. As a result, the product must contain ethanol (at least, say, 20%).
    The active components are still a work in progress but will likely be an extraction including apple polyphenols (procyanidin B2), nigella sativa (thymoquinone), camellia sinensis (catechins; EGCG), and olea europea leaves (oleuropein). The extraction is performed using anhydrous ethanol at 40degC.
    In order to increase transdermal penetration, I’ve decided on the following base formulation:
    50% (v/v) ethanol
    30% (v/v) distilled water
    20% (v/v) 1,2-propanediol
    d-limonene (1.5% w/v)
    disodium EDTA (0.3% w/v)
    and a pH adjusted to 5.5 using citric acid.
    I don’t think a preservative would be necessary beyond a chelating agent given the high concentration of ethanol. Using less ethanol or a compound other than 1,2-propanediol may make the product more gentle but this specific base seems to be popular in research. I’d like to avoid DMSO in the formulation if possible. Finally, ideally the product should have a moderate shelf-life (i.e. at least six months at room temperature) but this isn’t a hard requirement.
    Does this general approach make sense? Also, given the mix of botanical products in the extraction, would adding an additional sequestrant like glucono delta-lactone and/or creating a moderate pH buffer make sense? Is there anything I’m missing here?
    Thanks, everyone!
    Anonymous replied 4 years, 4 months ago 2 Members · 3 Replies
  • 3 Replies
  • Gunther

    January 27, 2020 at 5:27 pm

    First you’ll need to determine which active ingredients you’ll use and only then determine the solvent required.
    Some ingredients are water soluble so no alcohol or PG is needed. For others you’ll need to add an emulsifier.

    You’ll need to find scientific studies, or conduct the studies yourself to make sure these “active ingredients” actually do anything against alopecia, most don’t.
    If they don’t you can reduce them to claim ingredient levels, but you’d be selling plain snake oil.

  • belassi

    January 27, 2020 at 8:01 pm

    I would prefer spray-on hair to spray-on scalp.

  • Anonymous

    January 28, 2020 at 8:05 am
    @Gunther My initial goal in creating this product is for myself. I like learning about these kinds of formulations so it’s a fun project to try to do it right and think through these details. I’m not entirely closed to the possibility of selling it but it’s not my goal. I’ve done a good amount of research on the effects of various botanicals as well as their constituents and solubility, etc. I’m not doing this for money — mostly for fun — and wouldn’t sell any non-functional or misleading product. At my core, I’m a scientist and a person who enjoys learning. I am also well aware that the magnitude of effect for something like this is small. If there were an easy solution, it would probably exist already. I definitely appreciate the sentiment though; there are certainly a lot of people selling effectively snake oil out there. My purpose in this posting, as in most things I do, is to enhance my knowledge.
    @Belassi Hahaha I definitely hadn’t read my title like that. Thanks for the laugh 🙂

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