This is an excellent ppt on Dermatological pharmacology highlighting types of formulations, topical preparations and the treatment of individual skin disorders with illustrations...!!

21. INTERESTING FACTS
• body’s largest organ
• average adult’s skin spans 21 square feet
• weighs 4.1 kg
• contains more than 11 miles of blood
vessels.
• skin releases as much as 11 litres of
sweat a day in hot weather.
• skin sheds 50,000 cells every minute.

25. Skin has three layers:
• The epidermis, the outermost layer of skin,
provides a waterproof barrier and creates
our skin tone.
• The dermis, beneath the epidermis,
contains tough connective tissue, hair
follicles, and sweat glands.
• The deeper subcutaneous tissue
(hypodermis) is made of fat and
connective tissue

28. DRUGS AND THE SKIN
DISORDERS
DR. V.SATHYANARAYANAN MBBS.,M.D., ACME
PROFESSOR OF PHARMACOLOGY
SRM MCH & RC

29. OVERVIEW
• Types of skin formulations – lotion, cream,
ointment, paste
• Topical preparations
• Treatment of individual skin disorders like
Acne, Alopecia , Scabies, Seborrhoeic
dermatitis (dandruff), Psoriasis, Urticaria,
Pediculosis ( lice ), Nappy rash, hyperhidrosis
• Cutaneous adverse reactions

30. SPECIFIC LEARNING
OBJECTIVES
• AT THE END OF THE SESSION ALL THE
LEARNERS SHALL BE ABLE TO
• Enumerate types of skin formulations and
compare, contrast each
• Define and Describe different topical
preparations with examples
• Outline the treatment of common individual
skin disorders
appropriately

31. Common types of topical
formulations
• cream
• ointment
• paste
• lotion
• gel

32. CREAM
• emulsion of water and oil
• classified as oil in water (o/w) or water in oil
(w/o) emulsions
• o/w creams (e.g. vanishing creams) spread
easily and do not leave the skin greasy and
sticky
• w/o creams (e.g. cold cream) are more
greasy and more emollient

37. CREAMS
• Oil-in-water creams- aqueous cream,
vehicle for water-soluble drugs
• Water-in-oil creams- oily cream, used on
hairy parts, vehicle for lipid soluble drugs
• creams contain emulsifiers and
preservatives  may cause contact allergy

39. OINTMENTS
• semi-solid preparations of hydrocarbons
• Greasy and thicker than creams
• By occlusion promote dermal hydration
• Used in chronic dry conditions
• Water-soluble ointments- easily washed off
• Non-emulsifying ointment- adhere to skin, a form
of occlusive dressing, messy, e.g- paraffin
ointment- for chronic dry, scaly conditions
• contains no water and does not require a
preservative

43. PASTES
• mixture of powder and ointment
• Very adhesive  give good protection to
small areas
• Prevent spread of drug into surroundings
• Absorb discharge
• E.g coal tar paste, lassar’s paste

46. LOTION
• any liquid preparation in which inert or active
medications are suspended or dissolved
• an o/w emulsion with a high water content
• lotions are easy to apply to large areas
• lotions are suitable for hairy areas, skin
prone to folliculitis/acne, intertriginous areas

48. LOTION
• most lotions are aqueous or hydroalcoholic
systems;
• small amounts of alcohol are added to aid
solubilization of the active ingredient(s) and
• to hasten evaporation of the solvent from the
skin surface

50. GEL
• transparent preparations containing
cellulose ethers or carbromer in water or a
water-alcohol mixture
• gels liquify on contact with the skin, dry
and leave a thin film of active medication
• gels tend to be drying
• they are useful in hairy areas
• they are cosmetically acceptable

53. Collodion
• flammable, syrupy solution of nitrocellulose in
ether and alcohol.
• There are two basic types: flexible and non-
flexible.
• The flexible type is often used as a surgical
dressing or to hold dressings in place.
• When painted on the skin, collodion dries to
form a flexible nitrocellulose film
• prep of cellulose nitrate

54. VEHICLES – LIQUID
FORMULATIONS
• Water is the most important component
• Can be a soak, a bath or a paint
• Wet dressings - to cleanse, cool and
relieve pruritus in acute inflammation e.g
normal saline
• SHAKE LOTIONS – e.g Calamine lotion –
applies powder conveniently & cools skin
• Can cause excessive drying
•

57. PHARMACOKINETICS OF SKIN
• Stratum corneum is the principal barrier and
reservoir
• Vehicles are designed to increase hydration
• Absorption varies with site
• Absorption further increased in inflammation ,
burns , exfoliation
• Occlusive dressing increases absorption by 10
fold

65. Factors to consider when
choosing a topical preparation:
• Always consider the effect of the vehicle.
• An occlusive vehicle enhances penetration
of the active ingredient and improves
efficacy.
• The vehicle itself may have a cooling,
drying, emollient, or protective action.
• It can also cause side effects by being
excessively drying or occlusive.

66. Factors to consider when
choosing a topical preparation:
• Match the type of preparation with the type
of lesions.
• For example, avoid greasy ointments for
acute weepy dermatitis.
• Match the type of preparation with the site
(e.g., gel or lotion for hairy areas).
•

67. Factors to consider
• Consider irritation or sensitization potential.
• Generally, ointments and w/o creams are
less irritating, while gels are irritating.
• Ointments do not contain preservatives or
emulsifiers if allergy to these agents is a
concern.

69. TOPICAL PREPARATIONS

70. TOPICAL PREPARATIONS
• Demulcents, Emollients,
• Adsorbants
• Astringents
• Irritants , counter-irritants
• Topical analgesics
• Caustics, escharotics, keratolytics
• Antipruritics
• Topical steroids
• Sunscreens,
• melanising agents, demelanising agents
• Miscellaneous

72. DEMULCENTS
• Inert substances which sooth inflamed
skin/ denuded mucosa
• Applied as thick colloidal solutions in water

75. EXAMPLES FOR DEMULCENTS
• Gum acacia,
• Gum tragacanth
• Methylcellulose used in nasal drops,
contact lens solutions
• Propylene glycol in cosmetics
• Glycerin – dry skin, cracked lips

77. EMOLLIENTS
• Hydrate , sooth, smoothen dry scaly conditions –
olive oil, arachis oil, cocoa butter, liquid paraffin
• Short-lived action
• Barrier Preparations- dimethicone cream,
Protect skin from discharges and secretions,
irritant
• Silicone sprays – pressure sores
• Masking creams- titanium oxide in an ointment
base
• Dusting powders- zinc ,starch, talc- cool,
lubricate, reduce friction

84. ADSORBANTS
• Finely powdered solids that bind irritants to
their surface
• Also Afford physical protection to the skin
• Magnesium/ zinc stearate, Boric acid
• aloe vera gel
• Feracrylum – stops oozing blood
• Sucralfate (topical ) – applied on bed sores,
burns

89. ASTRINGENTS
• Substances that precipitate proteins in the
superficial layer
• Toughen the surface, decrease exudation
• Eg tannic acid, tannins used for bleeding
gums
• Ethanol, methanol prevents bed sores, used
as after- shave
• Heavy metal ions – alum, zinc

92. IRRITANTS
• Stimulate sensory nerve endings 
produce cooling or warmth, pricking and
tingling
• Rubefacients – cause local hyperemia
• Vesicants – form raised vesicles

93. COUNTER-IRRITANTS
• Turpentine oil, eucalyptus oil
• When massaged  relieve headache,
muscular pain
• Camphor – produces cooling sensation of
skin, added in pain balms
• Thymol, methyl salicylate
• Menthol – from mint – has cooling, soothing
action
• Mustard plaster, capsaicin, canthridin

98. TOPICAL ANALGESICS
• Counterirritants and rubefacients- stimulate
nerve endings in intact skin , relieve pain in skin,
viscera or muscle supplied by same nerve root -
e g salicylates, menthol, camphor, capsaicin
• Topical NSAIDs - Relieve musculoskeletal pain
• Local Anesthetics- lidocaine and prilocaine
available as gels, ointments and sprays
• Volatile aerosol sprays- sports people use,
produces analgesia by cooling and placebo
effect

100. CAUSTICS AND ESCHAROTICS
• Caustic – corrosive,escharotic – cauterizer
• Cause local tissue destruction and
sloughing
• Used to remove moles, warts
• Eg podophyllum resin, silver nitrate,
phenol, trichloroacetic acid

103. KERATOLYTICS
• Dissolve the intercellular substance in the
stratum corneum
• Used on hyperkeratotic lesions like corns,
warts, ring worm , psoriasis etc
• Eg salicylic acid- applied under polyethylene
occlusive dressing
• Resorcinol
• Urea

107. ANTIPRURITICS
• Histamine and other autocoids involved
• Generalized pruritus – treat the cause, oral H1
Antihistamines, sedatives
• Localized pruritus – covering the lesion, topical
corticosteroids for eczema, application of
aqueous menthol cream, calamine, astringents
( tannic acid ), crotamiton
• Local anesthetics, topical antihistamines induce
allergic dermatitis and better avoided

111. ADRENOCORTICAL STEROIDS
• Suppress inflammation, immune responses
• Antimitotic activity- useful in psoriasis
• Vasoconstriction reduces entry of inflammatory cells
• Used For Symptom Relief
• apply thinly for short duration
• Most useful in eczematous disorders
• Choose appropriate vehicle and potency
• Use combined with antimicrobials if infection present

114. TOPICAL STEROIDS
• VERY POTENT- clobetasol – needed for
lichen planus, DLE
• POTENT- beclomethasone, fluocinolone
• MODERATELY POTENT- Clobetasone
• MILDLY POTENT- hydrocortisone (0.1-1%)-
adequate for eczema
• Intralesional injections occ. used

116. ADVERSE EFFECTS
• Infection may spread
• Skin atrophy occur in long term use
• Local hirsutism
• Depigmentation, acne
• Allergic dermatitis
• Potent steroids - not applied on face
• On eyelids enter eye cause glaucoma
• Rebound exacerbation of disease after abrupt
cessation
• Mild- mod potent are Effective and safe
•

119. SUNSCREENS
• Substances that protect the skin from harmful effects
of exposure to sunlight
• Para-aminobenzoic acid, camphors absorb UVB (
protection against sunburn, tanning, skin cancer,
aging)
• Benzophenone absorb UVA which cause skin
cancer, aging
• Titanium dioxide, zinc oxide, calamine act as a
physical barrier to UVA, UVB ( reflect )
• Useful in photosensitivity due to drugs or disease

124. Sunburn
• can be treated with
• oily calamine lotion,
• topical steroids,
• NSAIDs

125. SUNSCREENS
• Performance of a sunscreen is expressed
as SPF ( sun protective factor )
• Daily application protects more
• Useful in drug induced phototoxicity
• Facilitate tanning
• Adjuncts in vitiligo therapy

129. DRUG INDUCED
PHOTOSENSITIVITY
• Doxycycline
• Sulphonamides, Chlorpromazine
• Frusemide, thiazides
• piroxicam
• TREATMENT- withdraw the offending
drug

132. INTERESTING FACTS ABOUT
SKIN
• White skin appeared just 20,000 to 50,000
years ago, as dark-skinned humans migrated
to colder climates and lost much of their
melanin pigment.
• In a lifetime the average person sheds enough
skin cells to fill an entire 2 story house.
• Every square inch of the human body has
about 19,000,000 skin cells.
•

140. MELANIZING AGENTS
• Drugs that promote repigmentation of
vitiliginous areas of skin
• Psoralen – stimulate melanocytes and
induce their proliferation
• Methoxsalen, trioxsalen
• Sensitize skin to sunlight
• Topically or orally and vitiliginous area is
exposed to sunlight under supervision

142. DEMELANISING AGENTS
• Lighten the hyperpigmented patches on
skin
• Hydroquinone – inhibits tyrosinase,
decrease formation and increase
degradation of melanosomes
• Used for melasma, chloasma of pregnancy
etc – incomplete response
• Monobenzone- destroys melanocytes
• Azelaic acid – weak agent

145. MISCELLANEOUS
• Squalene used in prevention of bedsores
• TARS- mild antiseptic, antipruritic, inhibit
keratinization in psoriasis
• Zinc oxide- astringent, barrier
• Urea- topically used to assist skin hydration in
ichthyosis
• Insect repellents – deet, dimethyl phthalate

149. There is an ancient story ... man asked God,
"God, why did you make women so pretty?“
"So you will like them," God answered.
And man asked God, "Why did you make women so
soft?
"So you will like them," God
answered again.
"And why," asked man again, "did you make them
so stupid?“
And God answered, "So they will like you.!!"

152. INDIVIDUAL SKIN PROBLEMS

155. ACNE
• Androgen  increases sebum  with
abnormal keratin form debris  plugs
follicle, propionibacterium acnes colonizes
 releases inflammatory fatty acids
irritate ducts  comedones are formed
• Apply mild keratolytics- benzoyl peroxide,
azelaic acid, salicylic acid
• Systemic or topical antimicrobial therapy
low dose erythromycin, tetracycline

158. ACNE
• VITAMIN A DERIVATIVES- Tretinoin topically,
may promote skin cancer, teratogenic
• Adapalene- better tolerated synthetic retinoid
• Isotretinoin- highly effective, used only in severe
cases as it’s a serious teratogen, raise
Cholesterol, TG, cause depression
• HORMONE THERAPY- Estrogen, cyproterone,
cyclical use of OCPills
• Topical corticosteroids should not be used

163. ALOPECIA
• MALE PATTERN BALDNESS- Topical
minoxidil in UPTO 50% people some
hair growth
• ALOPECIA AREATA- Finasteride by
mouth, PUVA

169. SCABIES
• Caused by Sarcoptes scabiei
• Permethrin dermal cream
• Topical Benzyl benzoate emulsion
• Topical Gamma benzene hexachloride
• Topical crotamiton in children
• Oral ivermectin single dose  recently
• Apply to all members, change bed clothes
after application

176. ANTI-SEBORRHEICS
• Drugs effective in seborrheic dermatitis
characterized by erythematous, scaly
lesions ( dandruff )

179. SEBORRHOEIC DERMATITIS
(DANDRUFF)
• Shampoo containing selenium sulfide, zinc
pyrithione or coal tar
• Ketoconazole shampoo in more severe
cases
• Keratolytics –salicylic acid
• Sulfur, resorcinol – mildly effective
• Occasionally corticosteroid lotion

183. PSORIASIS
• An Immunological disorder
• Manifests as localised or widespread
erythematous scaling lesions or plaques
• Increased proliferation , inflammation of
epidermis and dermis
• Drugs can decrease lesions but not cure

185. PSORIASIS
• Topical Emollients, keratolytics, antifungals
• Dithranol paste
• Topical adrenal steroids- primary drugs
• Vitamin D – calcipotriol topically
• Vitamin A derivatives – acitretin
• PUVA therapy – psoralen followed by ultraviolet
light , used in severe cases
• Ciclosporin , methotrexate

189. URTICARIA
• ACUTE URTICARIA, ANGIOEDEMA  H1
blockers, corticosteroids, adrenaline for severe
cases
• Cyproheptadine preferred for physical
urticarias
• CHRONIC URTICARIA – responds to
cetirizine, loratadine

193. PEDICULOSIS ( LICE )
• Permethrin two applications 7 days apart
• Insecticides like Carbaryl or malathion

198. NAPPY RASH
• PREVENTION - Rinse reusable nappies
with soaps, Use emollient cream to protect
skin, disposable nappies
• TREATMENT – MILD- zinc cream or
calamine lotion
• Severe- topical steroid with antimicrobial

202. HYPERHIDROSIS
• Astringents - reduce sweat
• Antimuscarinics given by iontophoresis
• Botulinum toxin injection locally  axilla
temporary remission for 16 weeks

204. CUTANEUS ADVERSE REACTIONS
• Allergic contact dermatitis – caused by
antimicrobials , local anesthetics
• Patients with AIDS- increased risk
• Maculopapular reactions are the most frequent –
ampicillin, sulfonamides, sulfonylureas
• Fixed eruptions – sulfa
• Pigmentation- OCPills

206. Treatment
• remove the cause,
• cooling applications ,
• antipruritics,
• H1 blockers

208. SUMMARY

209. • IF IT’S WET, DRY IT;
IF IT’S DRY , WET IT

211. MCQs
• 1. Which of the following substance is a keratolytic ?
• A) Tannic acid B) Liquid paraffin
• C) Salicylic acid D) Sucralfate
• 2. Eucalyptus oil and Turpentine oil are
• A) Demulcents B) Emollients
• C) Counter-irritants D) Caustics
• 3. Which of the following is a VERY POTENT topical
corticosteroid preparation ?
• A) Clobetasol B) Clobetasone
• C) Hydrocortisone D) Beclomethasone

212. MCQs
• 4. Vitiligo is treated with
• A) Hydroquinone
• B) Trichloroacetic acid
• C) Calamine
• D) Psoralen
• 5. Topical Minoxidil is helpful in treating
• A) Acne vulgaris
• B) Alopecia
• C) Scabies
• D) Seborrheic dermatitis

213. PART 2. WRITE SHORT NOTES ON
• 1. Sunsreens - preparations and uses
• 2. Drugs used in the treatment of Acne
• 3. Drug therapy of Psoriasis

217. Right education should help the
student, not only to develop his
capacities, but to understand his own
highest interest - Jiddu Krishnamurti