Bio skin care

BIO SKIN CARE
How do topical medicines reach their intended site? This article will explore the basic pharmaceutical aspect of skin absorption. Why should we as estheticians be concerned about topical medications our clients are using? Medications can alter the skins sensitivity, cause slight irritation as well as increase the likelihood of sunburns. This is particularly important when our clients come in for monthly facials or other skin care procedures. We must have some understanding of topical preparations our clients are using. Not having some knowledge can enhance or hinder skin care procedures.
The skin is a large organ, weighing approximately 4 kg and covering an area of 2 square meters. The skin acts as a barrier to absorption of chemicals and invasion by microorganisms. It prevents water loss as well as ----keeping us within and the world without. In order for dermatologists to treat skin disease effectively, medications must be able to penetrate the barrier properties of skin. Caution must be exercised whereby, if too much medication is absorbed, toxicity may result.


Percutaneous Absorption (performed through the skin)
Per-cutaneous absorption is the process by which a substance moves from the skin surface to its intended site of action or to the circulation system. For a topical agent to be effective, it must first be absorbed. The drug must enter in adequate concentration to its proposed site of action to produce the desired response of the skin. Another consideration a physician must acknowledge is the skin acts as a barrier in that it prevents chemicals and other materials from entering the body. This barrier is effective and useful, but it may hinder the treatment because the barrier also prevents absorption of medicines.
Skin Absorption Factors
There are many that affect skin absorption.
Absorption occurs by distribution around and through the cells that make up the skin. Some absorption takes place along hair follicles or through sweat ducts. Placing a drug on the skin does not mean that the drug will reach the intended site.
Organic solvents (containing carbon, which dissolve) can damage the stratum corneum and allow easier penetration by these chemicals.
Skin thickness and barrier accessibility are different in various areas. For example, hydro cortisone (a synthetic preparation used in the treatment of inflammations, allergies and itching) is absorbed through the skin 6 times better on the forehead than on the arm, and 44 times better on the scrotum.
Applying more of a substance increases the amount absorbed. Penetration will stop when the skin is saturated. Absorption into the bloodstream is also increased if the concentration of a substance is higher and if more body is is covered.
The skin of infants is more prone to absorption than those of adults.
Diseased skin is not necessarily easier to penetrate than normal skin.
Occluded (skin that has been covered) or well-hydrated skin is easier to penetrate than nonoccluded or dry skin.
The vehicle may affect penetration of a drug.
How Absorption Occurs
The drug is applied to the skin’s surface and then diffuses out of its vehicle into the stratum corneum. In the stratum corneum it builds a reservoir and defuses through the stratum spinosum. At this point, it can metabolize and drug binds to receptors and exerts its effect. The drug than passes into the basement membrane zone and dermis, drug metabolizes and binds to receptors. Drug is delivered into subcutaneous fat, the circulatory system and achieved systemic absorption.
Determining The Dose and Regimen
The dose is the quantity of medicine to be administered at one time and the regimen is a strictly regulated program. The concentration of the applied dose, the surface area of the body, and the elapsed time the chemical is on the skin are the main considerations affecting absorption. As the concentration of a drug is increased, the total amount absorbed into the skin and body also increases. Increasing the surface area of the applied dose also increases penetration. Penetration occurs over time. The longer the substance is on the skin, the greater the chance for continued penetration. Chances for toxicity may occur when high concentrations of a drug are spread over a large area of skin.
The total amount of a drug absorbed during a 24-hour period may be different for a single application as opposed to the same amount applied in divided doses. In other words,
applying a medicine once a day in the morning delivers a different concentration as opposed to applying a medicine 3 times a day 8 hours apart. What this implies is that the skin becomes saturated with the first topical application, so that absorption from repeated applications may need to be altered.
Not Everyone’s The Same
Individuals vary in the amount of medication they absorb through the skin. Physicians take this into account when they evaluate the results of topical therapy. The location of the body where the drug or chemical is applied varies in absorption as well.
High absorption is found on the: Head Neck Scrotum Arm pits These are areas with greater exposure to cosmetics and the environment.

For an example, hydro-cortisone is absorbed: 4 times better on the scalp 6 times better on the forehead 13 times better on the jaw 1 times better on the forearm 4 times better on the armpits 2 times better on the abdomen 42 times better on the scrotum 0.4 times better on the leg 0.1 times better on the soles of the feet. Compromised and Diseased Skin Most drug testing to determine the efficacy of a drugs absorption ability are studied on normal skin, but drugs are usually applied to diseased skin. The assumption is that skin’s ability to act as a barrier is compromised when the skin is diseased thereby allowing greater penetration. Skin that has abnormal redness over widespread areas of the body and which is shedding in scales or layers is easier to penetrate with topical. In Conclusion
Having a basic comprehension of topical absorption will aid you in understanding what your clients are experiencing when a skin disorder requiring a doctor’s visit is required. We all have at some point in our lives applied topical medications for a variety of conditions. Whether it was contact dermatitis while hiking from a poisonous plant, sunburn from a vacation or more severe and perhaps disfiguring conditions. The skin is a fascinating organ, which keeps us within, and the world without.
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