Drugs Acting on Skin and Mucous Membrane | Animals

After reading this article we will learn about the various drugs acting on skin and mucous membrane of an animal.

Classification:

1. Demulcents:

(i) Gum acacia

(ii) Gum tragacanth

(iii) Glycyrrhiza (liguroice)

(iv) Glycerine

(v) Propylene glycol

(vi) Methyl cellulose

(vii) Glycerine of starch (8.5% starch and 74.5% glycerine in D.W.).

(viii) Mucilage of starch (2.5.% starch).

2. Emollients:

(i) Vegetable oils:

(a) Olive oil

(b) Arachis oil

(d) Oil of theobroma (cocoa butter)

(ii) Animal Products:

(a) Wool fat (Lanolin)

(b) Wool alcohol

(d) Bees Wax

(e) Spermaceti.

(iii) Petroleum Products:

(a) Soft paraffin

(b) Hard paraffin

(d) White petroleum (Vaseline)

(iv) Others:

(a) Polyethylene glycol

(b) Propylene glycol

3. Adsorbents and Protectives:

(i) Dermal protectives:

(a) Magnesium stearate

(b) Zinc stearate

(d) Calamine

(e) Zinc oxide

(f) Bentonite

(g) Boric acid

(h) Starch

(ii) Gastrointestinal protectives:

(a) Kaolin (hydrated aluminium silicate)

(b) Pectin (Plant polysaccharide)

(d) Chalk

(e) Magnesium trisilicate

(f) Aluminium hydroxide

(iii) Occlusive protectives:

(a) Collodion (Pyroxylon) – nitrated cellulose given with castor oil

(b) Dimethicone (dimethyl polysiloxane, simethicone) → form Silicone polymer-amphiphilic liquid which acts as a surfectant.

4. Astringents:

(i) Tannic acid and tannins.

(ii) Alcohol (ethanol and methanol) → 50 – 90%

(iii) Mineral astringents:

(a) Bismuth carbonate

(b) Alum (aluminium sulphate)

(d) Zinc oxide/phenosulfonate.

(e) Zirconyl hydroxychloride.

(f) Zinc sulfate

(g) Calamine (Zinc oxide + ferric oxide).

(iv) Vegetable astringents:

(a) Tannic acid,

(b) gallic acid,

(d) Krameria,

(e) rubus ( blackberry).

5. Counter-irritants:

(i) Volatile oils:

(a) Turpentine oil

(b) Eucalyptus oil

(ii) Steoroptenes (also volatile):

(a) Camphor

(b) Menthol

(iii) Mustard seeds

(iv) Capsicum

(v) Cantharidin

(vi) Methyl salicylate

(vii) Alcohol

(viii) Iodine

(ix) Mercuric iodide

(x) Ammonia.

6. Caustics (Corrosive) and Escharotics (Cauterizers):

(i) Podophyllum resin

(ii) Silver nitrate

(iii) Phenol (Carbolic acid)

(iv) Trichloro acetic acid (TCA)

(v) Glacial acetic acid

(vi) Caustic soda (NaOH) and potas (KOH).

(vii) Antimony trichloride

7. Keratolytics:

(i) Salicylic acid

(ii) Resorcinol

(iii) Benzoic acid

8. Wound-healing Agents:

(i) Lugol’s solution (5% I₂ and 10% K1 in distilled water)

(ii) Povidone iodine oint. (betadine, isodine)

(iii) Sod. iodide

(iv) Zinc oxide

(v) Zinc sulfate

(vi) Copper naphthenate solution.

(vii) Chlorhexidine diacetate oint.

(viii) Neomycin SO₄, Isoflupredone acetate, Tetracaine hcl, Topical powder (Neo-Predef with Tetracaine)

(ix) Trypsin, Peru balsum, castor oil liquid (Granulex V)

(x) Polyhydroxydine

(xi) Nitrofurazone

(xii) Furazolidone

(xiii) Zyderm.

9. Dermatologic and Otic (into ear) Agents:

(i) Undecylenic acid

(ii) Dimethyl sulfoxide (DMSO)

(iii) Topical Corticosteroids

A. Very Potent:

(a) Fluocinolone acetonide – 0.2%

(b) Beclomethazone dipropionate – 0.5%

B. Potent:

(a) Fluocinolone acetonide – 0.025%

(b) Triamcinolone acetonide – 0.1%

(d) Flucortolone – 0.5%

(e) Betamethazone valerate – 0.1%

(f) Betamethazone benzoate – 0.025%

(g) Betamethazone dipropionate – 0.05%

(h) Beclomethazone dipropionate – 0.025%

C. Moderately Potent:

(i) Flumethasone pivalate – 0.02%

(ii) Fluocinolone acetonide – 0.01%

(iii) Flucocortolone – 0.2%

(iv) Hydrocortisone – 1.0% with urea.

D. Mild:

(i) Dexamethasone – 0.01%

(ii) Hydrocortisone acetate – 0.1-1%

(iii) Methyl prednisolone – 0.025%

10. Topical Antimicrobials (Antibiotics and Antifungals):

A. Antibiotics:

(i) Neomycin sulfate (Nebasulf, Neosporin)

(ii) Gentamicin Sulfate

(iii) Polymyxin B (Nebasulf and, Neosporin)

(iv) Nystatin (Mycostin)

(v) Framycetin (Soframycin powder) – 1% Cream.

(vi) Oxytetracycline (Terramycin skin oint) – 3%

(vii) Chlortetracycline

(viii) Metronidazole

(ix) Acyclovir (Herpex cream) – 5%

(x) Povidone iodine (wokadine) – 5% oint. and sol”.

(xi) Kanamycin

(xii) Chloramphenicol

(xiii) Bacitracin (Nebasulf, Neosporin)

B. Antifungals:

(i) Clotrimazole (Surfaz SN – 1%, Abzorb powder – 1%)

(ii) Miconazole (Daktarin) – 2% gel.

(iii) Ketoconazole (Nizral) – 200 mg. tab.

(iv) Enilconazole

(v) Amitraz (in Demodectic mange)

(vi) Cuprimyxin

(vii) Copper sulfate

(viii) Malachite green (used in fish)

(ix) Formaldehyde solution (used in fish)

C. Others:

(i) Benzyl benzoate 25% emulsion (Ascabiol).

(ii) Amitraz (in mange)

11. Local Anaesthetics:

(i) Amethocaine

(ii) Benzocaine

(iii) Lignocaine hcl.

12. Medicated Shampoos (Antiseborrheics):

(i) Selenium sulfide (antidandruff) – 1%

(ii) Sulfur

(iii) γ-benzene hexachloride – 1-2% in shampoo.

(iv) Zinc pyrithione (antidandruff)

(v) Salicylic acid

(vi) Resorcinol

13. Ophthalmic Agents (on eye):

(i) Antibiotic preparations:

(a) Kanamycin sulfate Ophthalmic oint. (Kantrim Ophth oint.) – 3.5 mg/gm

(b) Kanamycin Sulfate Ophth. aquous solution (Kantrim Ophthalmic solution – 1%)

(d) Chloramphenicol-Prednisolone acetate Ophth Oint. (Chlasone) – 1 % and 0.25%

(e) Chloramphenicol Ophth. solution (Chlorasol) – 0.05% and 0.5%

(f) Gentamicin sulfate Ophthalmic solution and oint. (Gentocin) – 0.3% and 0.3%

(g) Gentamycin sulfate Sol” (Genticyn eye/car drop) – 0.3%

(h) Gentamycin-hydrocortisone acetate solution (Genticyn-HC eye/ear drop) – 0.3% and 1%

(i) Boric acid Ophth. oint. (1%)

(j) Neomycin SO4 (1700 units)-Polymyxin B (5000 unit)- gramicidin (25 unit) solution (per ml), (Neosporin eye drop).

(k) Norfloxacin solution (Norbactin eye drop) – 0.3%

(I) Norfloxacin-benzylkonium chloride (Norflox eye drop) – 0.3% and 0.022%

(m)Neomycin sulf-Zinc Bacitracin-Polymyxin B Ophth. Oint (Neosporin) – 5mg, 400 u and 5000 u/gm.

(n) Sulphacetamide solution (Albucid) – 10%, 20% and 30%.

(o) Framycetin sulf. oint (Soframycin ophth. Oint.) – 0.5%

(p) Oxytetracycline hcl oint. (Terramycin ophthalmic) – 1 %

(q) Acyclovir ophth. oint. (Ocuvir)-3%

(ii) Mydriatics and Miotics:

(a) Phenylephrine hcl (Drosyn eye drop) – 5% and 10%

(b) Tropicamide solution (Mydriacyl) – 1%

(d) Pilocarpine hcl solution (Pilocar) – 1%, 2%, 4%

Demulcents:

Demulcents are inert substances that soothe and relieve irritation primarily involving the mucous membrane. They may also be applied to the skin. Most demulcents are water soluble compounds with a high molecular weight e.g., gums, mucilages, and starches.

They tend to coat irritated or abraded tissue surfaces to protect the underlying cells from irritating contacts. They are often used as vehicles for drugs applied on the skin and mucous membranes.

Emollients:

Emollients are inert oily substances used to soothe and soften irritated skin and mucous membranes. Active drug components such as antimicrobial agents are often incorporated into emollients.

Adsorbents and Protectives:

Adsorbents are finely powdered, inert and insoluble solids capable of binding to their surface (adsorbing) noxious and irritant substances. They are also called protectives because they provide physical protection to the skin or mucosa. Other protectives form a continuous, adherent and flexible occlusive coating on the skin. Demulcents and emollients also serve as protectives.

Astringents:

Astringents are substances that precipitate proteins, but do not penetrate cells, thus affecting the superficial layer only. They toughen the surface making it mechanically stronger and decrease exudation. Permeability of the cell membrane is greatly reduced but the cell remains viable.

Counter-irritants:

Counter-irritants are substances which are applied to the skin to cause local irritation and inflammation. The reasoning which prompts their use is that, where a chronic inflammation exists, a counter-irritant will cause an over-riding acute inflammation with a great increase in vascularity and consequently an increased blood supply to the area.

This increased blood supply results in a greater concentration of blood-borne anti-disease factors such as leucocytes, increased nutrition, and an improved removal of waste products by the venous and lymphatic systems. It is hoped that when this acute inflammation subsides, the cause and some of the results of chronic inflammation will also have been removed.

There are three types of counter-irritants causing three stages of counter-irritation:

(i) Rubefacients:

They cause only mild irritation and a small increase in congestion-Liter ally translated the term means “to make red”. They often have pain-relieving or anodyne properties.

e.g.- Iodine, camphor, ammonia, turpentine and methyl salicylate.

(ii) Vesicants:

They cause severe irritation which damages the capillary system and results in serous exudates collecting in the superficial skin layers to form ‘blisters’, e.g. Mercuric iodide, cantharidin.

(iii) Pustulants:

They cause severe irritation that the deep layers of the skin are damaged and the blisters become filled, not with serous exudate, but with products of cellular destruction-(Pus). There are toxic and are not clinically used. No substance should normally applied in a manner or form capable of causing irritation beyond the stage of vesication.

Caustics and Escharotics:

Caustic means “Corrosive” and escharotic means “cauterizer”. These chemicals cause local tissue destruction and sloughing. An escharotic, in addition, precipitates proteins that exude to form a scab → gets fibrosed to form a tough scar.

They are used to remove moles, warts, condylomata, papillomas, to destroy horn buds in calves, and on keratotic lesions. Care is needed in their application to avoid ulceration. There is a common belief that all microorganisms are killed during cauterization, but this is not always so.

Keratolytics:

Keratolytics dissolve the intercellular substance in the horny layer of skin. The epidermal cells swell, soften and then desquamate. They are used on hyper-keratotic lesions like corns, warts, psoriasis, chronic dermatitis, ring worm, athletes foot, etc.

Medicated Shampoos:

Bathing of animals in suitable shampoos gives a convenient method of treating specific skin problems such as mange, and also allows for r.on specific treatment of problems such as pruritus (itching), or seborrhoea (excessive secretion of sebacious glands, leading to dandruff and oily skin).

Drugs Acting on Skin and Mucous Membrane | Animals | Pharmacology