Just the words "dry, cracked skin" are enough to make people reach for an ointment or lotion. And as the weather turns colder, dry skin becomes a common problem for most people. Of course, choosing a skin cream is a daunting task when faced with the multitude of products on the pharmacy shelf.
"There are plenty of choices in the market place," said Jeff Moore, an instructor of Pharmaceutics in the Pharmaceutical Sciences Department at University of the Sciences in Philadelphia. "Most of the time, it is just a question of personal preference."Moore, a coordinator of laboratories which provide his students hands-on experience in compounding a variety of lotions and creams, believes a little background on the make-up of skin creams would make selecting the right cream easier.Most lotions and creams contain one or both of the following agents-an oily agent and a watery agent. Most of the time, creams and lotions vary based on the amount of these two agents, or "phases" as they are commonly referred to by formulators.Some creams or lotions can contain most of one phase and almost none of the other. Or, these agents can exist in equal amounts. "In many cases, the 'feel' of a lotion or cream may run from very oily to not oily at all. It all depends on the relationship of the two phases," Moore said. Variations lie anywhere in between.Unless some unusual medical condition exists, such as Psoriasis, most skin damage occurs because of dryness. In the winter, the air lacks the same humidity as in the summer. The atmosphere contributes to dehydrating the skin at a faster rate during this time.It is during this period that creams or lotions with an oily feel come to the rescue and provide a covering that slows the escape of moisture from the exposed surface allowing re-hydrating from below. "We say oil-based lotions and creams have an 'occlusive' function in that they cover the skin and allow healing like a band-aid," explained Moore.These creams and lotions may also contain additives which have proven to provide softening and soothing properties to the skin. "These additives are commonly known by most people and appear on the label of over-the-counter preparations. But they are not considered medicinal agents and at a certain concentration, usually don't need to be prescribed by a dermatologist."The additives can range anywhere from natural products, such as aloe, herbs, cocoa butter, shea butter, and spices, to chemically-made compounds such as Vitamin E. The list is never-ending. There is even a long-used compound called coal tar that is a distillation by-product in the processing of coal. Coal tar, is taken from the coking process, and resembles a black ink-like substance which stains. "People would never apply coal tar directly to the skin," Moore said. "But uniformly mixed into a thick oily cream base, coal tar can be applied. While not fully understood as to how it works, this agent will irritate the skin in a way which helps jump-start the healing process."Ointments which contain coal tar need to be greasy and thick. If such an agent is not necessary, most people would prefer a less oily, more watery type of cream, the so-called, vanishing creams, which apply easier and leave no major residue on the skin. According to Moore, these lotions may contain less heavy additives which provide a soothing and hydrating action. The only drawback is that water-based creams don't remain on the skin as long as their oil-based counterparts and need to be re-applied more often.Some controversy exits in the use of vitamin agents in lotions or creams. There are those who say vitamin agents such as A, D, or E, have positive effect when directly applied to the skin. Others say the chemical agents have to be swallowed to give any benefit to the skin.For skin conditions which occur below the surface, some additives, such as fine particle sulfur, are used to help to break up or 'de-keratinize" the skin to let medicinal agents reach the problem area. Otherwise, the skin will act as a natural barrier to the outside world."Most of what you find on the store shelves is fine to apply to alleviate symptoms of dry skin. However, if you have excessive drying, excessive itching, discoloration, or bumps, you will need a medical application. You are not going to get certain medicinal agents off the shelf and need to see a medical professional for a prescription."Unsure of what might be the best ointment or lotion for you? Your pharmacist is in the ideal position to help.(Source: University of the Sciences in Philadelphia : December 2006.)