Dosage Form of External Skin Drug

Dosage forms for topical skin include solutions, tinctures and spirits, powders, lotions, oils, creams, ointments, pastes, plaster, paints, gels, aerosols, and the like.

1. solution

Solution refers to an aqueous solution of the drug.

The main role: has a clean, astringent effect, mainly used for wet compress, wet compress has to reduce congestion and edema and remove secretions and scab and other effects, if the solution contains antibacterial anti-inflammatory ingredients can be used for the treatment of acute dermatitis and eczema.

Commonly used drugs: 3% boric acid solution, 0.05~0.1 berberine solution, 1:8000 potassium permanganate solution, 0.2~0.5 aluminum acetate solution, 0.1 copper sulfate solution, etc.
2. tinctures and spirits

Tincture and spirit refers to the ethanol solution or infusion of drugs, tincture is ethanol solution of non-volatile drugs, spirit is ethanol solution of non-volatile drugs.

The main role: tincture and spirit outside the skin, ethanol quickly volatilize, which will dissolve the drug evenly distributed on the surface of the skin, play its role.

Commonly used drugs: 2.5% iodine tincture, compound camphor spirit, etc.

3. powder

A powder is a powdered drug.

Main function: drying, protection and heat dissipation. It is mainly used for acute dermatitis lesions without erosion and exudation, especially for inter-rubbing sites.

Commonly used drugs: talcum powder, zinc oxide powder, calamine powder, etc.

4. Lotion

Lotion, also known as the oscillation agent, is generally a mixture of 30% to 50% powder and water, but the two are immiscible.

Main effects: antipruritic, heat dissipation, drying and protection.

Commonly used drugs: calamine lotion, compound sulfur lotion, etc.

5. oil

Oil is the use of vegetable oil to dissolve drugs or mixed with drugs.

Main function: cleaning, protection and lubrication. Mainly used for acute dermatitis and eczema.

Commonly used drugs: 10% camphor oil, 25% ~ 40% zinc oxide oil, etc.
6. emulsion

Emulsion is a dosage form of oil and water emulsified.

The main role: water-soluble and fat-soluble drugs can be mixed into emulsion, with protection, moisturizing effect, good permeability, mainly for subacute, chronic dermatitis. Water-in-oil type, slightly greasy, mainly used for dry skin or in the cold season. Oil-free type, easy to wash off, suitable for oily skin.

7. Ointment

The ointment is a dosage form using petroleum jelly, a single ointment (vegetable oil plus beeswax) or animal fat or the like as a base.

Main function: It has the function of protecting wound surface and preventing dry crack. Ointment has better permeability than emulsion. Adding different drugs can play different therapeutic effects. It is mainly used for chronic eczema, chronic simple lichen and other diseases. Because the ointment can prevent water evaporation, it is not conducive to heat dissipation. Therefore, it is not suitable for acute dermatitis and eczema exudation period.

Commonly used drugs: 0.25 erythromycin ointment, etc.

8. paste

Pastes are ointments containing 25% to 50% solid powder ingredients.

Main effects: similar to ointment, containing more powder, have a certain absorption and convergence effect, more for mild exudation of subacute dermatitis, eczema, hair parts should not use paste.

Commonly used drugs: compound zinc paste, etc.

9. Plaster

Hard paste is a semi-solid matrix composed of fatty acid salt, rubber, resin, etc. attached to cloth, paper, perforated plastic film and other backing materials.

Main function: plaster can be firmly adhered to the surface of the skin, the role of long-lasting, with to prevent water loss, soften the skin and enhance the role of drug permeability.

Commonly used drugs: zinc oxide plaster, peel a plaster, etc.

10. coating agent

Coating agent is the drug and film-forming materials such as sodium carboxymethyl cellulose, dissolved in volatile solvents (such as acetone, ether, ethanol, etc.) made.

Main function: The solvent evaporates rapidly and forms a uniform film on the skin. It is often used to treat chronic dermatitis.

Commonly used drugs: chilblain coating agent, its main drug composition is: camphor 80g, ethyl nicotinate 20g, pepper extract 150g, belladonna extract 20g, dibutyl phthalate 40g, polyvinyl alcohol acetaldehyde 150g. The above drugs were added to a mixture of 1 part ethanol and 3 parts acetone for a total weight of 1000 grams.

XI. Gel

Gel is based on organic polymer figures and organic solvents such as propylene glycol, polyethylene glycol as the matrix with a drug.

The main role: gel can form a thin layer, cool, lubricating, for acute, chronic dermatitis can be used.

Commonly used drugs: benzoyl peroxide gel, etc.

XII. Aerosols

Aerosol, also known as spray, is a mixture of drugs and polymer film-forming materials (such as polyvinyl alcohol, butyraldehyde) and liquefied gases (such as freon). It refers to a clear liquid, suspension or emulsion made by filling a drug and a suitable propellant in a pressure-resistant closed container with a special valve system. When in use, the contents are sprayed out as mist particles by the pressure of the propellant.

Main function: After spraying, the drug is usually distributed on the skin surface, which can be used to treat acute and chronic dermatitis or infectious skin diseases. The aerosol may act locally or systemically in the respiratory tract, skin or other lumen. At present, aerosol has been used in the treatment of asthma, burns, ear, nose and throat diseases and expectorant, vasodilation, cardiac, diuretic, etc., have received significant results.

Commonly used drugs: aerosol propellants commonly used for trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane and other compressed gases such as carbon dioxide, nitrogen and so on.

XIII. Other

Such as dimethyl sulfoxide (DMSO) can dissolve a variety of water-soluble and fat-soluble drugs, also known as universal solvent. The DMSO dosage form of the drug often has good transdermal absorbability, such as 1% to 5% laurocaprone solution also has good transdermal absorbability, and has no irritation to the skin and mucosa.