Topical medication

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A medical professional applies nose drops. Instilling nasal medication.jpg
A medical professional applies nose drops.
Instilling eye medication Instilling eye medication.jpg
Instilling eye medication

A topical medication is a medication that is applied to a particular place on or in the body. Most often topical administration means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes including creams, foams, gels, lotions, and ointments. [1] Many topical medications are epicutaneous, meaning that they are applied directly to the skin. Topical medications may also be inhalational, such as asthma medications, or applied to the surface of tissues other than the skin, such as eye drops applied to the conjunctiva, or ear drops placed in the ear, or medications applied to the surface of a tooth. The word topical derives from Greek τοπικός topikos, "of a place".

Contents

Local versus systemic effect

The definition of the topical route of administration sometimes states that both the application location and the pharmacodynamic effect thereof is local. [2]

A transdermal patch which delivers medication is applied to the skin. The patch is labelled with the time and date of administration as well as the administrator's initials. Applying transdermal patch.jpg
A transdermal patch which delivers medication is applied to the skin. The patch is labelled with the time and date of administration as well as the administrator's initials.

In other cases, topical is defined as applied to a localized area of the body or to the surface of a body part regardless of the location of the effect. [3] [4] By this definition, topical administration also includes transdermal application, where the substance is administered onto the skin but is absorbed into the body to attain systemic distribution. Such medications are generally hydrophobic chemicals, such as steroid hormones. Specific types include transdermal patches which have become a popular means of administering some drugs for birth control, hormone replacement therapy, and prevention of motion sickness. One example of an antibiotic that may be applied topically is chloramphenicol.

If defined strictly as having local effect, the topical route of administration can also include enteral administration of medications that are poorly absorbable by the gastrointestinal tract. One poorly absorbable antibiotic is vancomycin, which is recommended by mouth as a treatment for severe Clostridium difficile colitis. [5]

Choice of base formulation

A medication's potency often is changed with its base. For example, some topical steroids will be classified one or two strengths higher when moving from cream to ointment. As a rule of thumb, an ointment base is more occlusive and will drive the medication into the skin more rapidly than a solution or cream base. [6]

The manufacturer of each topical product has total control over the content of the base of a medication. Although containing the same active ingredients, one manufacturer's cream might be more acidic than the next, which could cause skin irritation or change its absorption rate. For example, a vaginal formulation of miconazole antifungal cream might irritate the skin less than an athlete foot formulation of miconazole cream. These variations can, on occasion, result in different clinical outcomes, even though the active ingredient is the same. No comparative potency labeling exists to ensure equal efficacy between brands of topical steroids (percentage of oil vs water dramatically affect the potency of topical steroid). Studies have confirmed that the potency of some topical steroid products may differ according to manufacturer or brand. An example of this is the case of brand name Valisone cream and Kenalog cream in clinical studies have demonstrated significantly better vasoconstrictions than some forms of this drug produced by generic drug manufacturers. [6] However, in a simple base like an ointment, much less variation between manufacturers is common.

In dermatology, the base of a topical medication is often as important as the medication itself. It is extremely important to receive a medication in the correct base, before applying to the skin. A pharmacist should not substitute an ointment for a cream, or vice versa, as the potency of the medication can change. Some physicians use a thick ointment to replace the waterproof barrier of the inflamed skin in the treatment of eczema, and a cream might not accomplish the same clinical intention.

Classes

There are many general classes, with no clear dividing line among similar formulations. As a result, what the manufacturer's marketing department chooses to list on the label of a topical medication might be completely different from what the form would normally be called.

Cream

A cream is an emulsion of oil and water in approximately equal proportions. It penetrates the stratum corneum outer layer of skin wall. Cream is thicker than lotion, and maintains its shape when removed from its container. It tends to be moderate in moisturizing tendency. For topical steroid products, oil-in-water emulsions are common. Creams have a significant risk of causing immunological sensitization due to preservatives and have a high rate of acceptance by patients. There is a great variation in ingredients, composition, pH, and tolerance among generic brands. [7]

Foam

Foam can be seen with topical steroid marketed for the scalp.[ citation needed ]

Gel

Gels are thicker than liquids. Gels are often a semisolid emulsion and sometimes use alcohol as a solvent for the active ingredient; some gels liquefy at body temperature. Gel tends to be cellulose cut with alcohol or acetone. Gels tend to be self-drying, tend to have greatly variable ingredients between brands, and carry a significant risk of inducing hypersensitivity due to fragrances and preservatives. Gel is useful for hairy areas and body folds. In applying gel one should avoid fissures in the skin, due to the stinging effect of the alcohol base. Gel enjoys a high rate of acceptance due to its cosmetic elegance. [7]

Lotion

Lotions are similar to solution but are thicker and tend to be more emollient in nature than solution. They are usually oil mixed with water, and more often than not have less alcohol than solution. Lotions can be drying if they contain a high amount of alcohol.

Ointment

Metal case for Cruz Roja ointment from Mexico (beginning of the 20th century) from the permanent collection of the Museo del Objeto del Objeto. CruzRojaPomada.JPG
Metal case for Cruz Roja ointment from Mexico (beginning of the 20th century) from the permanent collection of the Museo del Objeto del Objeto.

An ointment is a homogeneous, viscous, semi-solid preparation, most commonly a greasy, thick oil (oil 80% - water 20%) with a high viscosity, that is intended for external application to the skin or mucous membranes. Ointments have a water number that defines the maximum amount of water that they can contain. They are used as emollients or for the application of active ingredients to the skin for protective, therapeutic, or prophylactic purposes and where a degree of occlusion is desired.

Ointments are used topically on a variety of body surfaces. These include the skin and the mucous membranes of the eye (an eye ointment), chest, vulva, anus, and nose. An ointment may or may not be medicated.

Ointments are usually very moisturizing, and good for dry skin. They have a low risk of sensitization due to having few ingredients beyond the base oil or fat, and low irritation risk. There is typically little variability between brands of drugs. They are often disliked by patients due to greasiness. [7]

The vehicle of an ointment is known as the ointment base. The choice of a base depends upon the clinical indication for the ointment. The different types of ointment bases are:

The medicaments are dispersed in the base and are divided after penetrating the living cells of the skin.

The water number of an ointment is the maximum quantity of water that 100g of a base can contain at 20 °C.

Ointments are formulated using hydrophobic, hydrophilic, or water-emulsifying bases to provide preparations that are immiscible, miscible, or emulsifiable with skin secretions. They can also be derived from hydrocarbon (fatty), absorption, water-removable, or water-soluble bases.

Evaluation of ointments[ citation needed ]
  1. Drug content
  2. Release of medicament from base
  3. Medicament penetration
  4. Consistency of the preparation
  5. Absorption of medicament into blood stream
  6. Irritant effect

Properties which affect choice of an ointment base are:[ citation needed ]

  1. Stability
  2. Penetrability
  3. Solvent property
  4. Irritant effects
  5. Ease of application and removal
Methods of preparation of ointments

Paste

Paste combines three agents - oil, water, and powder. It is an ointment in which a powder is suspended.

Powder

Powder [8] is either the pure drug by itself (talcum powder), or is made of the drug mixed in a carrier such as corn starch or corn cob powder (Zeosorb AF - miconazole powder). Can be used as an inhaled topical (cocaine powder used in nasal surgery).

Shake lotion

A shake lotion is a mixture that separates into two or three parts over time. Frequently, an oil mixed with a water-based solution needs to be shaken into suspension before use and includes the instructions: "Shake well before use".[ citation needed ]

Solid

Medication may be placed in a solid form. Examples are deodorant, antiperspirants, astringents, and hemostatic agents. Some solids melt when they reach body temperature (e.g. rectal suppositories).

Sponge

Certain contraceptive methods rely on sponge as a carrier of a liquid medicine. Lemon juice embedded in a sponge has been used as a primitive contraception in some cultures.

Tape

Cordran tape is an example of a topical steroid applied under occlusion by tape. This greatly increases the potency and absorption of the topical steroid and is used to treat inflammatory skin diseases.

Tincture

A tincture is a skin preparation that has a high percentage of alcohol. It would normally be used as a drug vehicle if drying of the area is desired.

Topical solution

Topical solutions can be marketed as drops, rinses, or sprays, are generally of low viscosity, and often use alcohol or water in the base. [9] [10] [11] These are usually a powder dissolved in alcohol, water, and sometimes oil; although a solution that uses alcohol as a base ingredient, as in topical steroids, can cause drying of the skin. [12] [ page needed ] There is significant variability among brands, and some solutions may cause irritation, depending on the preservative(s) and fragrances used in the base.

Some examples of topical solutions are given below:

  1. Aluminium acetate topical solution: This is colorless, with a faint acetous odour and sweetish taste. It is applied topically as an astringent after dilution with 10-40 parts of water. This is used in many types of dermatologic creams, lotions, and pastes. Commercial premeasured and packed tablets and powders are available for this preparation.[ citation needed ]
  2. Povidone iodine topical solution: This is a chemical complex of iodine with polyvinylpyrrolidone. The agent is a polymer with an average molecular weight of 40,000. The povidone iodine contains 10% available iodine, slowly released when applied to skin. This preparation is employed topically as a surgical scrub and non irritating antiseptic solution; its effectiveness is directly attributed to the presence and release of iodine from the complex. Commercial product: Betadine solution.[ citation needed ]

Transdermal patch

Transdermal patches can be a very precise time released method of delivering a drug. Cutting a patch in half might affect the dose delivered. The release of the active component from a transdermal delivery system (patch) may be controlled by diffusion through the adhesive which covers the whole patch, by diffusion through a membrane which may only have adhesive on the patch rim or drug release may be controlled by release from a polymer matrix. Cutting a patch might cause rapid dehydration of the base of the medicine and affect the rate of diffusion.

Vapor

Some medications are applied as an ointment or gel, and reach the mucous membrane via vaporization. Examples are nasal topical decongestants and smelling salt.

See also

Related Research Articles

Benzocaine Anesthetic

Benzocaine, sold under the brand name Orajel amongst others, is an ester local anesthetic commonly used as a topical pain reliever or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments such as products for oral ulcers. It is also combined with antipyrine to form A/B otic drops to relieve ear pain and remove earwax. In the US, products containing benzocaine for oral application are contraindicated in children younger than two years old. In the European Union, the contraindication applies to children under 12 years of age.

Antipruritics, also known as anti-itch drugs, are medications that inhibit the itching often associated with sunburns, allergic reactions, eczema, psoriasis, chickenpox, fungal infections, insect bites and stings like those from mosquitoes, fleas, and mites, and contact dermatitis and urticaria caused by plants such as poison ivy or stinging nettle.

Clobetasol propionate

Clobetasol propionate is a corticosteroid used to treat skin conditions such as eczema, contact dermatitis, seborrheic dermatitis, and psoriasis. It is applied to the skin as a cream, ointment, or shampoo. Use should be short term and only if other weaker corticosteroids are not effective. Use is not recommended in rosacea or perioral dermatitis.

Moisturizer Type of cosmetics

Moisturizer or moisturiser is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. The word "emollient" is derived from the Latin verb mollire, to soften.

Betamethasone

Betamethasone is a steroid medication. It is used for a number of diseases including rheumatic disorders such as rheumatoid arthritis and systemic lupus erythematosus, skin diseases such as dermatitis and psoriasis, allergic conditions such as asthma and angioedema, preterm labor to speed the development of the baby's lungs, Crohn's disease, cancers such as leukemia, and along with fludrocortisone for adrenocortical insufficiency, among others. It can be taken by mouth, injected into a muscle, or applied to the skin topically in cream, lotion, or liquid forms.

Desonide

Desonide (INN) is a low-potency topical corticosteroid anti-inflammatory that has been available since the 1970s. It is primarily used to treat atopic dermatitis (eczema), seborrheic dermatitis, contact dermatitis and psoriasis in both adults and children. It has a fairly good safety profile and is available as a cream, ointment, lotion, and as a foam under the tradename Verdeso Foam. Other trade names for creams, lotions, and ointments include Tridesilon, DesOwen, Desonate. It is a group VI corticosteroid under US classification, the second least potent group.

Calamine

Calamine, also known as calamine lotion, is a medication used to treat mild itchiness. This includes from sunburn, insect bites, poison ivy, poison oak, or other mild skin conditions. It may also help dry out skin irritation. It is applied on the skin as a cream or lotion.

Betamethasone dipropionate

Betamethasone dipropionate is a glucocorticoid steroid with anti-inflammatory and immunosuppressive abilities. It is applied as a topical cream, ointment, lotion or gel (Diprolene) to treat itching and other minor skin conditions such as eczema.

Fluocinonide

Fluocinonide is a potent glucocorticoid used topically as an anti-inflammatory agent for the treatment of skin disorders such as eczema and seborrhoeic dermatitis. It relieves itching, redness, dryness, crusting, scaling, inflammation, and discomfort.

Cream (pharmacy)

A cream is a preparation usually for application to the skin. Creams for application to mucous membranes such as those of the rectum or vagina are also used. Creams may be considered pharmaceutical products as even cosmetic creams are based on techniques developed by pharmacy and unmedicated creams are highly used in a variety of skin conditions (dermatoses). The use of the finger tip unit concept may be helpful in guiding how much topical cream is required to cover different areas.

Perioral dermatitis

Perioral dermatitis, also known as periorificial dermatitis, is a common type of skin rash. Symptoms include multiple small (1–2 mm) bumps and blisters sometimes with background redness and scale, localized to the skin around the mouth and nostrils. Less commonly the eyes and genitalia may be involved. It can be persistent or recurring and resembles particularly rosacea and to some extent acne and allergic dermatitis. The term "dermatitis" is a misnomer because this is not an eczematous process.

Lotion Skin treatment preparation

A lotion is a low-viscosity topical preparation intended for application to the skin. By contrast, creams and gels have higher viscosity, typically due to lower water content. Lotions are applied to external skin with bare hands, a brush, a clean cloth, or cotton wool.

Skin care

Skin care is the range of practices that support skin integrity, enhance its appearance and relieve skin conditions. They can include nutrition, avoidance of excessive sun exposure and appropriate use of emollients. Practices that enhance appearance include the use of cosmetics, botulinum, exfoliation, fillers, laser resurfacing, microdermabrasion, peels, retinol therapy and ultrasonic skin treatment. Skin care is a routine daily procedure in many settings, such as skin that is either too dry or too moist, and prevention of dermatitis and prevention of skin injuries.

Clocortolone

Clocortolone (Cloderm) is a topical steroid. It is used in the form of an ester, clocortolone pivalate, and applied as a cream. It is used for the treatment of dermatitis and is considered a medium-strength corticosteroid. It is unusual among steroids in that it contains a chlorine atom and a fluorine atom.

Amcinonide

Amcinonide is a topical glucocorticoid used to treat itching, redness and swelling associated with several dermatologic conditions such as atopic dermatitis and allergic contact dermatitis. Amcinonide can also be classified as a multi-functional small molecule corticosteroid, which has been approved by the FDA and is currently marketed as an ointment, lotion, or cream. It acts as both a transcription factor for responses to glucocorticoids and modulator for other transcription factors while also regulating phospholipase A2 activity.

Dosage form

Dosage forms are pharmaceutical drug products in the form in which they are marketed for use, with a specific mixture of active ingredients and inactive components (excipients), in a particular configuration, and apportioned into a particular dose. For example, two products may both be amoxicillin, but one is in 500 mg capsules and another is in 250 mg chewable tablets. The term unit dose can also sometimes encompass non-reusable packaging as well, although the FDA distinguishes that by unit-dose "packaging" or "dispensing". Depending on the context, multi(ple) unit dose can refer to distinct drug products packaged together, or to a single drug product containing multiple drugs and/or doses. The term dosage form can also sometimes refer only to the pharmaceutical formulation of a drug product's constituent drug substance(s) and any blends involved, without considering matters beyond that. Because of the somewhat vague boundaries and unclear overlap of these terms and certain variants and qualifiers within the pharmaceutical industry, caution is often advisable when conversing with someone who may be unfamiliar with another person's use of the term.

Esoterica is an over-the-counter topical ointment applied to the skin for the purpose of lightening freckles, age spots, chloasma, melasma, and other skin discolorations due to a benign localized increase in the production of melanin. Esoterica may have other appropriate medical uses as determined by a physician.

Topical steroids are the topical forms of corticosteroids. Topical steroids are the most commonly prescribed topical medications for the treatment of rash, eczema, and dermatitis. Topical steroids have anti-inflammatory properties, and are classified based on their skin vasoconstrictive abilities. There are numerous topical steroid products. All the preparations in each class have the same anti-inflammatory properties, but essentially differ in base and price.

Diflucortolone valerate

Diflucortolone valerate (also Nerisone cream/oily cream/ointment, Neriderm ointment, Japanese ジフルコルトロン is a corticosteroid rated Class 2 "potent" in the New Zealand topical steroid system. It is a white to creamy white crystalline powder. It is practically insoluble in water, freely soluble in dichloromethane and in dioxan, sparingly soluble in ether and slightly soluble in methyl alcohol. Chemically, it is a corticosteroid esterified with valeric acid. It is commonly used topically in dermatology. The brand name is Nerisone; its creams come in potencies of 0.1% and 0.3%.

Aquaphor

Aquaphor is a brand of over-the-counter (OTC) skin care ointments manufactured by Beiersdorf Inc., an affiliate of Beiersdorf AG. Aquaphor is offered in four product ranges: There are two skin protectant ointments. Aquaphor Original Ointment, used as a compounding agent and Aquaphor Advanced Therapy Healing Ointment, sold in mass retail outlets. The other product ranges include: Aquaphor Lip Repair and Lip Repair + Protect SPF 30, and Aquaphor Baby.

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  7. 1 2 3 Wolverton, S. Comprehensive Dermatologic Drug Therapy. p. 13.
  8. "Doctor, why are you prescribing an ointment?"; American Academy of Dermatology
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