Formula Anatomy Deciphered—Feminine Hygiene Products

By: Luigi Rigano, PhD, Studio Rigano Industrial Consulting Laboratories

Posted: December 4, 2012, from the December 2012 issue of Cosmetics & Toiletries.

page 5 of 6

With no need for sweat reduction in the female genital area, aluminum-based antiperspirant actives are not advisable for female hygiene products. The acidiy developed by the salt during the day could be irritating to this sensitive area. The key odor-fighting ingredient of this category of products is the perfume, which must be long-lasting and discrete at the same time (popular notes used in feminine hygiene product include iris, white flowers, talc and rose notes).

Some products in the market claim to protect the vaginal area from bad odors through the use of the perfume ingredient pentadecalactone. This is an interesting volatile ingredient with an intense musk perfume. It is present in nature in many essential oils, notably angelica roots, and in, among other fruits, pears. It is a persistent scent used in the fragrance, flavor and pharmaceutical industries.¹⁹ As some perfumes could complicate the skin irritation potential profile of the formula, adequate safety experiments should be carried out before launching the final formula. When formulating a product for an area near a mucos membrane, it is always wise to be familiar with product safety restrictions for the distribution country.

Intimate Skin Care

Intimate area skin encounters a great deal of stress from the combined actions of temperature, friction, microbes, compression and occlusion. In addition, the capability of the skin to maintain the proper grade of moisturization and mechanical properties lessens with time. An emollient and, in some cases, lubricating action is often necessary, and are progressively more necessary as age increases in order to avoid additional discomfort. For more on polymers in lubricants, read " Getting Intimate with Polymers: Personal Lubricants."

On the outer genital, for both men and women, the skin sensitivity and the thin layer skin requires efficient emollient actions. This is necessary in case of any disease leading to impaired sebum production or in any other skin imbalance. This is the field where formulator creativity has shown maximum performance.

There are two categories of moisturizing/lubricating gels: those based on glycerin gels (Formula 2), which are lubricating and water soluble; and anhydrous lipid gels (Formula 3), which are intended to exert a moisturizing and soothing action through a combination of occlusion and water organization properties. Skin lubrication without stickiness is a must in this category of products.