Razor advances improve shaving results

Key Points

A: Many of the newer razors have experienced inflation in blade number. The original razor was a single blade that morphed into a two-bladed razor in the 1970s. The concept was that the first blade lifted the hair and the second blade cut the hair.

This quickly gave way to the three-bladed razor in the 1990s, where the first blade lifted the hair, the second blade cut the hair and the third blade cut the hair even closer.

It's also important to note that the newer blades have a wave in the metal. This is designed to minimize friction between the rigid metal blade and the flexible skin. In order to make the blades less rigid, the newer blades are spring-mounted to allow the metal to more accurately traverse the mountains and valleys of the skin. Friction is further reduced with the glide strip on the leading edge of the blade that pulls and prepares the skin for contact by the razor.

Razor blade design is a carefully studied science. There is no substitute for a well-designed blade in obtaining the optimal shave. Old razor blades or blades that have been dropped or exposed to solvents are permanently damaged and cannot deliver a quality shave. The best way to get a great shave is to use a new, quality blade.

Q: Does shaving decrease the efficacy of armpit antiperspirants?

A: Shaving decreases the efficacy of armpit antiperspirants, especially in women who frequently shave the armpits.

Antiperspirants function by creating a protein plug in the acrosyringium of the eccrine unit, thus preventing the flow of perspiration onto the skin surface. This plug must be maintained with continued application of the antiperspirant.

Aggressive armpit shaving physically removes the plug, allowing the eccrine sweat to flow freely. Thus, in women who complain of hyperhidrosis, the efficacy of topical over-the-counter antiperspirants can be improved by decreasing the frequency of shaving, applying less pressure with the razor and shaving only once over a given skin area.

Q: Why is glycerin found in so many therapeutic moisturizers?

A: Glycerin is one of the newest - and oldest - ingredients in therapeutic moisturizers. While this may seem to be an oxymoron, it's true!

The first commercially successful moisturizer (other than petrolatum) was Corn Husker's Lotion. Corn Husker's Lotion is almost pure glycerin and was used by farmers to smooth rough hands from manual labor.

It has now been recognized that glycerin is one of the few moisturizing substances that can modulate aquaporin channels in the skin. Aquaporin channels are pores in the walls of cells that function like a faucet to control the entry and exit of water in and out of the cell, thus maintaining water balance.

Too much water in the cell would result in bursting, and too little water in the cell would cause dehydration. The aquaporin 3 channels in the skin function to maintain the delicate osmotic balance necessary for life.

Glycerin is transported in aquaporin 3 channels and can aid in the modulation of water balance. It was known some years ago that the effect of glycerin on the skin lasted long after it was applied. This was termed the glycerin reservoir effect, since it was thought that the glycerin was incorporated into the intercellular lipids.

It is now known that the long-lasting effect of glycerin-containing moisturizers is due to aquaporin modulation.

Zoe Diana Draelos, M.D., is a Dermatology Times editorial adviser and consulting professor of dermatology, Duke University School of Medicine, Durham, N.C. Questions may be submitted via e-mail to zdraelos@northstate.net
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