This is a guest post by Gary Neudahl. He is currently Product Application Manager, Personal Care Ingredients, for the HallStar Company and is based at the HallStar Manufacturing and Technical Center in Bedford Park IL USA.
As the days get shorter and colder and the air gets drier, we direct our attention to the composition of lip balms.
Why use lip balms?
If package claims tell the story (1), they are used primarily for their moisturizing and hydrating effects and (when sunscreen active ingredients are incorporated) for their sunscreening effects. Common product positionings revolve around botanical / herbal content and vitamin and/or mineral content. More about that later.
As with lipsticks, relatively few ingredient types are required to prepare a stable and superior-performing product, although proper selection and processing are critical for optimal effect. Here are the typical components of a lip balm:
Emollient Carriers 40 – 85%
Flavor 0 – 0.5%
Waxes 10 – 20%
Label Copy Ingredients 0 – 0.5%
Active Ingredients 0 – 50%
Preservatives 0 – 0.3%
Photostabilizers 0 – 6%
Antioxidants 0 – 0.1%
Lip balm raw materials
Emollient carriers (which, when solid sunscreen active ingredients are incorporated, are also sunscreen solvents) are the largest component by weight. Their proper selection contributes the product’s unique feel and delivery characteristics and also affects the physical and photochemical stability of the product. The most commonly utilized emollient carriers are Ricinus Communis (Castor) Seed Oil, Butyrospermum Parkii (Shea) Butter, Petrolatum, Octyldodecanol, Mineral Oil (Paraffinum Liquidum), Simmondsia Chinensis (Jojoba) Seed Oil and Lanolin. It is obvious from this list that lip balms aren’t greening as rapidly or extensively as some other personal care product segments. There are several reasons for this: the superior moisturization and
occlusivity of certain petroleum- (and animal-) derived ingredients, the tastelessness of many petroleum-derived products, and the greater oxidation resistance of the saturated hydrocarbon products.
Waxes are used to provide structure. A range of waxes is necessary so the lip balm provides the desired pay-off and feel while also maintaining stick integrity at high (melting makes a mess!), moderate (syneresis is a turn off!) and low (cracking makes for difficult use!) temperatures . The more commonly utilized waxes include a lower melting point, softer wax, Beeswax (Cera Alba), a hard and higher melting point wax, Euphorbia Cerifera (Candelilla) Wax (Candelilla Cera), and a high melting point, brittle wax, Copernicia Cerifera (Carnauba) Wax (Copernicia Cerifera Cera). Their proper proportioning is what helps the formulating chemist earn his lofty reputation and pay!
Active ingredients for lip care, in the USA, fall into one of two main Over-the-Counter (OTC) drug monograph categories: skin protectants and sunscreens. The monographs define the ingredients, their specifications and use levels, and the combinations of ingredients allowed to make claims. The top monographed skin protectant ingredients in lip balms include Petrolatum, Mineral Oil, Lanolin, Dimethicone, Theobroma Cacao (Cocoa) Seed Butter and Allantoin.
You’ve seen some of these mentioned earlier among the emollient carriers, so they are multifunctional ingredients. How much skin protectant ingredient is needed in a lip balm to make a skin protectant claim? Only 0.5% for Allantoin and 1% for Dimethicone, but 50% for Cocoa Butter and for Mineral Oil! The most commonly used sunscreen active ingredients (UV filters) used in lip balms are Ethylhexyl Methoxycinnamate (Octinoxate), Titanium Dioxide, Butyl Methoxydibenzoylmethane (Avobenzone), and Benzophenone-3 (Oxybenzone). These represent the best balance between high and broad spectrum UV absorbance (or scattering) and low bitterness among authorized UV filters.
When photolabile UVA-absorbing Avobenzone is included in a lip balm to impart broad spectrum UV protection, incorporation of Ethylhexyl Methoxycrylene and/or Polyester-25 (if Octinoxate is also present), Undecylcrylene Dimethicone and/or Polyester-8 is recommended to photostabilize the Avobenzone and so retain the lip balm’s broad spectrum UV protection through prolonged sun exposure.
Because some fraction of the lip balm is inevitably going to be ingested, it is important to select a flavor / fragrance that is toxicologically benign, both topically and orally, and that conforms to regulatory requirements for lip care products. An increasing number of geopolitical zones are requiring the declaration of flavor / fragrance ingredients that are known sensitizers. Commonly listed ones in lip balms include Linalool, Benzyl Benzoate, Citral, Geraniol and Citronellol. As mentioned earlier, some lip balm ingredients have a taste (in addition to any odor) and, unfortunately, that taste is often perceived as bitter. So a masking agent may be included towards reducing the lip balm’s bitterness. Most frequently used is Saccharin or Sodium Saccharin.
We’ve covered “label copy” ingredients in earlier articles. These are ingredients, often added at incredibly low levels, which are included not because they are functional but because they garner consumer interest and initial product trial. As noted earlier, for lip balms, botanical / herbal and vitamin and/or mineral content have been the primary hooks from a marketing perspective.
Given a nonaqueous (no water) base for the typical lip balm, one might think that preservatives are unnecessary, and that’s generally true, particularly if buyers aren’t sharing their lip balms with one other (teenagers!). However, there is a secondary effect from certain preservatives that may be of benefit in lip balms. Specifically, the most commonly utilized preservatives for lip balms are parabens, and parabens (at sufficient concentration) have a numbing effect on the tongue. So including parabens in a lip balm may help mitigate the bitterness of the formulation.
Our last ingredient category is that of antioxidants. Antioxidants are particularly valuable in lip care products since the tongue and nose are very sensitive to peroxidation products. It is therefore important, with respect to both product esthetics and shelf life, to include antioxidants in lip care products when unsaturated materials (whether from botanical sources or synthetic flavor or fragrance compounds) are present. The most commonly utilized antioxidants in lip balms are Tocopheryl Acetate and Tocopherol, with lesser use of BHT and Ascorbyl Palmitate.
And that’s it! Thank you for reading! If you have additional questions on lip balms, or you’d like to see a different personal care product deconstructed and explained, contact the author at firstname.lastname@example.org. Your interest is appreciated.
(1) Information on claims and frequency of use in this article are based on a Mintel GNPD full search on the word “balm” within the category “lip care” on 8 October 2012.