Inactive Ingredients Just as Important as Active Ingredients

Rosacea sufferers get good at looking through ingredient listings. What magical ingredient has been included in this product that might help me?

But rosacea sufferers need to keep reading and take notice of everything listed.

Recent research is highlighting just how important all of the ingredients are in a topical preparation.

The benefits to your skin from the vehicle components help explain why one might even obtain relief from vehicle-only preparations.

For example if you are on a clinical trial that is blinded. Particularly if your skincare regime is not supporting the functions of your skin, the vehicle carrying the active ingredient in a topical may itself be worth using.

This further reinforces the argument that a gentle (and supportive) skincare regime is important for rosacea sufferers.

Of course mixing your own topicals is not an easy task, so mostly we are limited to the formulations that have been made for us by the pharmaceutical companies.

As a refresher here is a listing of ingredients of the most popular rosacea topicals. As you can see it is not an easy task to discover just from the listing whether a topical is going to be a winner for you.

Metrogel Ingredients

METROGEL (metronidazole gel), 1% is an aqueous gel; each gram contains 10 mg of metronidazole in a base of betadex, edetate disodium, hydroxyethyl cellulose, methylparaben, niacinamide, phenoxyethanol, propylene glycol,propylparaben and purified water.

Finacea Ingredients

Each gram of Finacea contains 0.15g (15%) micronized azelaic acid in a gel base. It also contains 0.1% benzoic acid, propylene glycol, polysorbate 80, lecithin, polyacrylic acid, triglycerides (medium chain), sodium hydroxide, disodium edetate and purified water.

Plexion Ingredients

Each gram of Plexion® (sodium sulfacetamide USP 10% and sulfur USP 5%) Topical Suspension contains 100 mg of Sodium Sulfacetamide USP and 50 mg of Sulfur USP in a suspension containing: Purified Water USP, Propylene Glycol USP, Isopropyl Myristate NF, Light Mineral Oil NF, Polysorbate 60, Sorbitan Monostearate NF, Cetyl Alcohol NF, Hydrogenated Coco-Glycerides, Stearyl Alcohol NF, Fragrances, Benzyl Alcohol NF, Glyceryl Stearate (and) PEG-100 Stearate, Dimethicone NF, Zinc Ricinoleate, Xanthan Gum NF, Edetate Disodium USP, and Sodium Thiosulfate USP.

Klaron Ingredients

Each mL of Klaron (sodium sulfacetamide lotion) Lotion, 10% contains 100 mg of sodium sulfacetamide in a vehicle consisting of purified water; propylene glycol; lauramide DEA (and) diethanolamine; polyethylene glycol 400, monolaurate; hydroxyethyl cellulose; sodium chloride; sodium metabisulfite; methylparaben; xanthan gum; EDTA and simethicone.

Research Abstracts

Topical rosacea therapy: the importance of vehicles for efficacy, tolerability and compliance, J Drugs Dermatol. 2011 Jun 1;10(6):627-33, Jackson JM, Pelle M.

Many topical medications are available for the treatment of papulopustular rosacea. While treatments contain metronidazole, azelaic acid, or sodium sulfacetamide-sulfur as the active ingredient, the composition of the vehicle formulations varies widely.

These vehicles come in gels, creams, lotions and foams; some ingredients are common to many vehicles, while some vehicles contain unique ingredients designed to optimize skin penetration and delivery of the active drug to its target.

Vehicles can also influence tolerability, which is always a concern in patients with heightened skin sensitivity, and compliance, which is typically lower for topical treatments than oral treatments.

Ideally, the vehicle of any rosacea treatment should enhance drug delivery, be non irritating and be easy to use. Ingredients that help repair barrier function are also desirable. This review will focus on the key components of the vehicles from the most commonly used topical therapies for papulopustular rosacea and how vehicle formulations influence the delivery of active ingredient, skin barrier repair, tolerability and compliance.

Further related research;


Emil A. Tanghetti, MD, Chair, A Supplement to Skin & Allergy News,

Skin Disease Education Foundation’s 29th Annual Hawaii Dermatology Seminar, a continuing medical education program, March 18-24, 2005, in Maui, Hawaii.

Physicians attempting to balance aggressive acne treatment with tolerability stress the importance of restoring hydration of the stratum corneum. Research demonstrating the stratum corneum’s pivotal role in drug delivery has sparked renewed interest in this topic.

Many common conditions directly and indirectly affect barrier function.  For example, atopic dermatitis, psoriasis, and acne affect barrier function directly through the impact of the inflammatory process on epidermal growth and maturation. Medications used to treat a number of conditions indirectly disrupt barrier function.  Topical retinoids—the mainstay of acne treatment—change and disrupt barrier function.

Several signs and symptoms characterize damage to the epidermal barrier.  Dryness and peeling occur when the water content of the stratum corneum falls below 10%.  This creates a damaged and leaky epidermis that may lead to overabsorption of topical medications and products, causing even more barrier damage.


Restoring and maintaining barrier function is critical for outcomes in patients with dermatologic diseases.  For optimal hydration, a vehicle that is both occlusive and humectant is ideal.  The addition of moisturizers such as dimethicone and glycerin to acne treatment products helps maintain barrier function and will provide better outcomes. This is particularly important when topical retinoids are included in the therapeutic regimen. For comedonal acne, combination products containing moisturizers may be effective first-line agents. Finally, clinicians should consider the vehicle prior to prescribing or recommending any products to patients with acne.

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About the Author

About the Author: David Pascoe started the Rosacea Support Group in October 1998. .

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