Topical medication for dermatological diseases

2021-03-24 12:00 AM

Topical drugs also have a systemic effect, causing certain biological changes, because the drug is absorbed into the forest solution, into the bloodstream.

Outline

Topical treatments for the skin are very rich, diverse and have the following origins:

Chemical origin:

Inorganic: metals, metal salts, nonmetals and their derivatives such as oxides, acids.

Organic: fats, aromatics, aldehydes, acetone, phenols, acids ...

Herbs.

Synthetic and semi-synthetic substances.

The mechanism of action of topical drugs

Enhance or limit, even hinder water evaporation through the skin. There are types that increase the contact area of ​​the skin, make it easier to evaporate water through the skin, cool the skin, prevent blood condensation, reduce inflammation. In contrast, there are topical drugs that block the skin, limit sweat evaporation, increase skin congestion.

Affects skin circulation, causes vasodilation or vasoconstriction.

Depending on the form of the drug and the excipients, the drug will penetrate the skin more or less, shallow or deep.

But usually, all three types of effects work together. For example, the gelatinize, at the same time increases the water vapour in the skin, cools the skin, dissolves the blood, but does not allow the drug to penetrate deeply into the skin. On the contrary, the ointment interferes with water evaporation in the skin, causing congestion, vasodilation.

Attention should be paid to the chemical and physical effects of the drug:

The drug changes the pH of the skin.

Drugs can affect redox in cells, by using either deoxidizer or by oxygen transfer.

Topical drugs also have a systemic effect, causing certain biological changes, because the drug is absorbed into the forest solution, into the bloodstream, affects the peripheral receptor nerve, or acts on the mediastinum. psychoactive plant nerve.
Thus, topical drugs have both local and systemic effects, and the indications and use of topical drugs should be very careful.

Absorption of the drug through the skin

The "grease film" on the skin has an affinity for water, so aqueous substances can still be absorbed through the skin, but fat-soluble substances (mercury salts, lead salts) are more easily absorbed.

The stratum corneum acts as an organic membrane and is a major obstacle to the absorption of aqueous substance, to ensure a good absorption through the stratum corneum it is important to pay attention to the pH of the drug (the pH of the stratum corneum is markedly acidic: pH = 4, pH of the dermis is slightly alkaline).

The drug is also absorbed through the skin by hair follicles, sebaceous glands, it has been proven that: a salt entering the body to work must be through the skin with many blood vessels. Rub, spray on the skin to facilitate absorption of the drug, especially the ointment form.

The damaged skin absorbs drugs other than healthy skin, thick secretions, scarring or super production of the horny layer to limit drug absorption through the skin.

The absorption of drugs through the skin depends on the properties of the chemicals used, volatile substances such as chloroform, iodine, and mercury will be strongly absorbed, fat-soluble substances will slowly absorb into the skin. more, water-soluble salts will seep into the skin, enter the circulatory system.

In summary: the absorption of the drug through the skin depends on the state of the horny layer, the layer of fat covering the skin, the state of the skin appendages, the acidity of the skin, the properties of the active substances used, the form of drugs and solvents used, their reaction on the skin and their ion dissociation. The effects and combined effects of the above factors will determine the absorption rate of the skin and the effect of topical drugs.

Topical forms

The general structure of a topical formulation: usually consists of 2 main ingredients

Active ingredient: has a therapeutic effect, such as iodine, which has a fungicidal effect, and salicylic acid scabs ...

Excipients: are means of transporting active ingredients, bringing active ingredients into the skin, excipients themselves have no therapeutic effect, but it still has an important role, the drug is shallow or deep depending on the form of the drug. , excipients are used in topical formulations. 

Excipients commonly used are: water, alcohol, vaselin, lanolin, powder ...
When choosing excipients, attention should be paid to the physical and chemical effects of the active ingredients, solubility and incompatibility.

The most common types of topical medications include

Solutions.

powders

Ointment (pommades.ointment.).

Pates.

cream.

Oil medicine (huiles).

Some other forms:

Varnish (vernis).

Colles.

Gauze, soak, bath.

Solutions:

The active ingredient is mixed in excipients (usually liquid solvents) into a uniform, non-clumping, non-precipitating liquid.

Excipients are usually water, alcohol, volatile solvents (ether, acetone, chlorofoc, sometimes using glycerine), these substances absorb strongly.

Solution in water: commonly used excipients are distilled water, so use a freshly prepared distilled water with neutral pH, in many cases also use isotonic solution compared to the patient's serum. solution of sodium chloride or another neutral salt, or a sugar (glucose, sucrose).

With some aqueous substances, the real solution does not form but a fake solution, also known as solutions colloid ales, in which there are extremely small particles suspended in solution. Albumin substances and soap derivatives, and colourants mixed with water will give colloidal solutions.

Alcohol solution: usually use 30 0 - 70 0 alcohol.

The solution in alcohol is more beneficial than the solution in water is more absorbent and more volatile, but strong alcohol can cause skin irritation and dryness due to excessive defatting.

Alcohol is used to dissolve some mineral salts, many organic substances, herbs, alcohol, to concentrate albumin, which has an antiseptic effect.

Some solutions:

Jarish solution includes boric acid 20 grams, glycerol 40 grams, distilled water enough 1000 grams. 

Millian solution includes methylene blue, gentian purple, rivanol, (the same) 1 g, alcohol 70 0  10 g, distilled water, enough for 1000 grams.

Castellani solution: Fuschia, boric acid 0.60 g, phenic acid, acetone, à la 1.0 g, resocxin, alcohol 70 0 3.0 g, distilled water 50 g.

In general, the solution has a shallow, temporary effect and is often used in the acute or subacute phase.

Some ways to use the solution are as follows:

Apply gauze: cover the affected area 8-12 layers of gauze, continuously water, the medicine solution basket into it to create a moist environment of the medicinal solution within 24h - 72 hours. Apply gauze to reduce inflammation, anti-congestion, anti-watery, antiseptic, anti-itch, clean pus, scabs.

Cold compress: Put the drug in boiled water to cool, use absorbent gauze to cover 5 - 10 minutes, 3-4 times a day, effective to reduce inflammation in case of acute inflammation, watery like eczema acute.

Hot compress: impregnate with hot water gauze on the skin, dilate capillaries, strengthen phagocytosis, soothe inflammation.

Solution used to apply on the skin has an antiseptic effect such as millian solution, 1% methanol solution.

Soak, bathe:

Soak and bathe a solution of 1 / 10,000 dilute purple medicine to treat infectious skin diseases. Bath with a sulfur bath with proper ratio of scabies treatment.

Powder :

Has the effect of cooling the skin, anti-congestion, reducing inflammation, absorbing water to dry the skin, reducing subjective feelings (itching, heat ...).

Excipients commonly used are two types of powder: herbal powder and mineral powder.

Herbs are often used as rice flour, wheat flour, quinoa soup powder, and charcoal powder. Rice flour is finer than wheat flour and has a very strong absorbent effect. Quince tree powder has astringent, antiseptic, and strong water absorption effects. Coal powder has the ability to absorb water and rot is quite good.

Mineral powder: more commonly used.

The main types of mineral powders are:

Dissolved powder (talc) means natural magnesium silicate, often used in combination with zinc oxide, which absorbs water and insulates.

Kaolin powder, or natural alumin silicate, is hydrophilic.

Magnesium carbonate powder has very strong water absorption properties.

Dermatol powder ie bismuth sous gallat is a yellow powder.

Solid or liquid active ingredients are easily mixed with the aforementioned powders, forming a smooth, uniform powder.

The powder is often used on a highly inflamed, acute or watering lesion. The powder is also used to sprinkle on long-healing ulcers. For example talc menthol 1% anti-itch powder (menthol 1 gram, talc powder, zinc oxide and just enough 100 grams.

Ointment (pomade, oitment):

The most important and popular form of topical medication.

Excipients are fats (vaseline, lanonine ...), the percentage of active ingredients <30%.

Ointment increases the absorption of the skin, penetrates much more deeply than other drugs, softens the skin, but, interferes with the excretion of the skin, blocking the skin, limiting sweating, causing congestion.

Do not use the ointment form on lesions that are acute or watery. Often use ointment form for chronic lesions.
Common excipients are:

Lard (axonge): easy to spread thin, easy to absorb, less irritating to the skin, long to become acidic with an unpleasant odour, preserved by adding benzoic acid.

Lanoline: yellowish-white colour, has a special odour, flows at 40oC, has an affinity for water, absorbs a large volume of water, is easily absorbed through the skin, often mixed with vaseline to make the drug soft and easy spread over skin.

Vaseline is the most common, extracted from kerosene residue, white, transparent, soft, flowing at 35 ° C, has no taste, is neutral, is not destroyed by acids and alkalis, is not affected by air. Gas, moisture, insoluble in water, vaseline does not absorb water, so when preparing an ointment with water-soluble active ingredients, vaseline must be mixed with lanoline.

The rate of the active ingredient in the fat formula is <30%.

Lake medicine (pâtes:

Ingredients include active ingredients and ointments (vaseline and lanolin) but with more powder, usually, the ratio of powder in the paste formula is 30% - 50%, the commonly used powders to make pasteurizers are: zinc oxide, tonsil, kaolines, calcium carbonates, magnesium carbonates.

The effect is more transient than ointment, does not penetrate deeply with ointment, reduces inflammation, reduces congestion, prevents blood condensation, dries out the skin, does not limit the excretion and evaporation of the skin, often used for skin lesions at the semi-level stage.

Cream pills (cremes, creams):

The cream can be considered as an ointment with added glycerin and water.

Ingredients include vaseline, lanolin, glycerin, stearate.

Has the effect of cooling the skin, protecting the skin, and moderate absorption. Often used as a cream for subacute skin lesions.

Oil medicine (huiles, oil):

Substances in the excipients are olive oil, neutral peanut oil, purple papaya oil, sesame oil, 30-40% powder can be added.

The effect is shallow, soothing the skin. Used in acute or superficial lesions.

Bathing (bain):

Use the solutions mentioned above.

Soak: usually used for lesions in the extremities, soak 1-2 times a day.

Bath for body injury.

Some commonly used topical medications

Antiseptic medicine

The antiseptic solution used to soak, apply gauze for ulcerative skin lesions, infections, discharge, with pus crust excretion such as infecting, acute eczema ...

Rivanol 1o / oo solution, yarish solution (with boric acid 3g, glycerin 40ml, distilled water 1000ml) becberin solution, 9o / oo NaCl solution, KMnO4 1/4000 solution, almond leaf juice, fresh tea leaf juice

Colorant solution used to apply to ulcerative, infectious skin lesions: 1% methyl purple solution, 1% methylene blue solution, Cestellani solution, Millian solution

Antibiotic ointment cream applied to the pathological lesions caused by bacteria, or infection when the lesions are dried: 1% Chlorocid ointment, 1% Tetracylin ointment, Silverin cream, Fucidin cream, Bactroban cream.

Scabies medicine

DEP oil (diethylphtalate), Eurax cream, dd pemethrin 1% Benzyl benzoate oil 33% dd Kwell cream, sulfur fat 10% (for children) 30% (for adults).

Medicines to treat ringworm, tinea versicolor, and interstitial fungus

Alcohol BSI 1,2,3%.

ASA alcohol, Benzosali grease (Whitefield).

Clotrimazol 1% ointment, Nizoral cream, Lamisil cream, Daktarin cream.

Drugs for treatment of Eczema, dermatitis

The solutions for soaking, covering the gauze (mentioned above) for Eczema can be used to relieve ulcers, discharge, and infections for the first 3-5 days.

The dye solution (mentioned above) on the first 7 - 10 days of ulcerative and infectious lesions.

Lake (zinc oxide ingredients, talc powder, glycerin, distilled water) cool the skin, reduce inflammation, antiseptic dry damage, protect the affected area, apply 2-3 times daily for dermatitis, acute Eczema.

Corticoid ointment cream: Eumovat cream, Tempovate cream, Temproson, Flucinar ointment, Benovate cream, Dermovate ointment, Diproson ointment, Celestoderm ointment, Aristocort… applied Eczema, subacute and chronic dermatitis.

Corticoid ointment cream + antibiotics: Diprogenta ointment, Celestoderm- neomycin ointment, Flucort-N ointment.

Corticoid ointment cream + antibiotic + anti-fungal.

Gentrison, Triderm, Endix, Ecodax.

Medication for acne

Eryfluid, Erythrogel, Dalacin T.

Metrogylgel, Panoxyl grease 2.5 - 5 - 10.

Eclaran Cream, RetinA Cream, Locacid ointment, Erylik Cream, Differin Cream, Isotrex Cream

Psoriasis medication

Salicylic Fat 2%, 3%, 5%.

Tar, Coaltar.

Corticoid ointment should only be used 1 time 20-30 days to apply once a day without using it for too long. Do not apply strong, do not apply too large area to avoid side effects.

Mỡ Daivonex, Daivobet.

Tazarotene.

Topical treatment for warts

Solution Duofilm, Collomark, Podophyllin (pay attention to protect the skin around the damage with zinc oxide ointment, for example, apply the correct medication to the affected area once a day, avoid the wire to the surrounding skin causing ulcers).

Antiviral drug for ennet, shingles

Acyclovir ointment cream, Varrax ointment

Androgen-related topical hair loss treatment

Minoxidil solution.

Chloralhydrate Salicylic 3%.

Topical anti-tanning agent, pigmentation

Leucodinin B fat 10%.

Renova cream (topical twice a day).

Some points to note when using topical drugs

Topical not only has a topical effect but also a systemic effect, the topical is absorbed into the skin, penetrates into the blood vessels, acts on the nerves, thereby acting on the whole body (e.g., salicylic ointment. wide area so the patient feels dizziness, headache ...).

The use of topical drugs must be consistent with the nature of the disease, the stage of the disease, the severity of the disease, the skin area, sometimes the age, gender, weather and occupation. For example, acute slippery eczema, drainage, pus, and secretory, need to specify a solution to apply gauze, soak, wash, pigment ... Chronic eczema uses the form of an ointment to reduce inflammation, reduce dullness, keratosis, interstitial areas. should limit the type of fat to cause blemish and squash. Some drugs cannot be applied to the face, genital area.

For the aetiology of the unknown pathogenesis, if the lesion is identified correctly, the appropriate ointment can be prescribed to help or cure the disease.

For lesions that have a lot of pus and secretions, soak, apply antiseptic solution 1 - 3 - 5 days to reduce inflammation, clear pus, scabs, then appoint more topical oedema. suitable for the next stage.

Do not apply a drug for too long, nor should constantly change the drug, making it difficult to assess the treatment results, as well as confirm the correct and wrong diagnosis ... Usually, a course of drug application takes about 10-15 days.

It should be noted that some classic topical drugs (goudron ...) still work well, some brand-name drugs may have side effects that have not been fully studied, not much experience in clinical use. sieve.

Carefully monitor the patient while taking the drug so that it can be adjusted in time.

Monitor the skin reactions of each patient as topical medications can cause allergies.