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.

The term hygiene here is defined as actions or behaviors that maintain the health and well-being of the body. The word hygiene comes from the Greek term hugieinē technē, which means “the healthful art” and “having a vigorous life.” When personal care products are formulated to maintain the hygiene of the external genital area, specifically the female genitalia, they must have distinctive characteristics. These products must address the female genitalia’s complex anatomy, physiological elements and role in body metabolism and reproductive functions.

Female Anatomy

The vaginal channel, which is open to the environment through the external genital organs, is characterized by a distinctive and complex equilibrium, variable in cyclic phases during a woman’s life. This multitasking area’s uniqueness has led it to be referred to as the vaginal ecosystem.¹ Its equilibrium is determined by three fundamental elements: glycogen in the vaginal epithelium tissue;² the activity of saprophyte bacterial species;³ and the presence of lactic acid. Among the many species that colonize the human body, Lactobacillus doderlein has a positive influence for the vaginal area, as it produces lactic acid in normal, healthy conditions.³ The presence of lactic acid determines local acidic pH values, more acidic than in any other epidermal district.

The presence of glycogen (i.e., the substance that lactobacillus use as a starting raw material for the production of lactic acid) is the key biochemical element. Optimal conditions for the vaginal channel include abundant glycogen, a stable pH of 3.5–4.5 and active lactobacillus.⁴ This low pH value hinders the proliferation of pathogenic microorganisms such as candida, herpes and gardnerella that can enter the vagina channel from the surrounding environment. These species can induce bothersome inflammation. Modified acidity conditions due to pathology, lack of hygiene, frequent cleansing, excessively perfumed cleansers, inadequate rinse-off or aggressive cleansing may influence both the acidity equilibrium and the whole physiology of the vaginal system.^5–7 (Read more about the Sensitive Skin Syndrome). The inside of the vagina is self-cleansing; therefore, the area does not normally require any special treatment. Moreover, the resident symbiotic, microbial flora protect from foreign, unwanted bacterial species.⁸

Feminine Hygiene Needs

Hygiene products are needed for the external part of the vagina, where the occlusion triggered by clothes, the residues of dead skin cells and the nutrient materials from traces of urine and other secretions can induce uncontrolled bacterial proliferation. Treating pH modification due to the formation of ammonia and aliphatic amines from bacterial growth, the development of bad odors and the possibility of skin inflammation requires careful cosmetic practices.

Some conditions may induce harmful changes in the vagina ecosystem. For example, immune deficiency (during menses) can promote the development of mycotic infections like Candida vulvovaginitis. Tight clothes also can be an aggravating factor, as they do not allow the moisture to wick away from the skin, supporting a warm and damp microhabitat. Moreover, some contraceptive systems and improper hygiene of the site can induce itch, promote microbial development and increase the risk of infections. (More about microbes in the human body.) The conditions of the vaginal ecosystem’s environment is complicated by the proximity of the anus, where microbial proliferation, tight clothes, hindered transpiration, sebum production and area compression from the bodyweight in seated position create maceration phenomena and additional irritation conditions.^{9, 10}