3. • Skin-the largest organ of body and most accessible organ
• Surface area 1.5 – 2m2
• Drug penetration is inversely proportional
to thickness of stratum corneum
5. ABSORPTION OF TOPICAL FORMULATIONS
Site
• Forearm
• Sole
• Palm
• Back
• Scalp
• Axilla
• Forehead
• Scrotum
Relative level of absorption
• 1.0
• 0.1
• 0.8
• 1.7
• 3.5
• 3.6
• 6.0
• 42
6. FACTORS AFFECTING TOPICAL ABSORPTION
• Drug concentration
• Site of application
• Age of patient
• Surface area applied
• Friction and heat
• Occlusion
• Hair follicles
• Cutaneous circulation
7. ADVANTAGES OF TOPICAL APPLICATIONS
• Achieve high concentration for drug in skin
• Minimal exposure to other organs
• Increase efficacy
9. HOW TO PRESCRIBE
A. Specify concentration of drug
B. Vehicle
C. Frequency
D. Quantity
10. A.CONCENTRATION OF DRUG:
Percentage representing the proportion of the formulation by weight or volume
• Weight– 1% W/W –1 gram of drug in 100 gram of formulation
• Volume- 1% W/V– solution contain 1 gram drug in 100 ml of formulation
• Parts- 1 part in 1000 solution - means 1 gram in 1000 solution
11. B.VEHICLE :
DEFINATION: Substance which is incorporated into a topical preparation in
order to facilitate the drug delivery by bringing the drug in contact with the
skin
AN IDEAL VEHICLE……….
• Elicits no pharmacological effect
• Solubilize the drug
• Releases the drug with appropriate kinetics
• Is chemically and physically stable
• Cosmetically appealing
• Non allergic and non irritating
12. CLASSIFICATION OF TOPICAL FORMULATIONS
Liquids Solutions A. Aqueous solution
Wet dressing
Soaks and baths
B. Alcoholic solution
1. tincture
2. Paints
3. Varnishes
4. Sprays
Lotions 1. solid in liquid
2. liquid in liquid
Liniments
14. DRESSING
A . WET DRESSING : antipruritic, vasoconstrictive
, cleansing and keratolytic
1. Open Wet dressing :acute inflammatory
conditions with exudation ans oozing.
2. Closed wet dressing : more maceration, less
evaporation
cellulitis and abscess
17. PAINTS:
• Liquid preparations,either aqueous, hydroalcoholic or alcoholic
• usually applied with a brush.
• Eg- gentian violet: antibiotic, anti candidial
- brilliant green: antibacterial
- castellani paint: intertrigo, paronychia,tinea
18. LOTIONS:
• Liquid formulations, suspension or solution of medication in water, alcohol or
other liquid.
• Advantages-convenient
- ratio of inert and active ingredients can be altered.
• Disadvantages- drying effect
- irritating
19. TINCTURES
• Alcoholic solutions designed to deliver large amount of active ingredients at a
site without any undesirable cosmetic effect.
• Used in areas which are not usually easily irritated such as scalp.
20. OINTMENTS:
• Semisolid vehicles composed of lipid such as White soft paraffin (BP
• Occlusive & emolient property
• Good hydration
• Used in chronic,dry,brittle,lichenified dermatoses
• Contain no water
• Do not sustain the growth of microorganisms
• Difficult to spread
• Decrease evaporation
• Can not be used in acute discharging lesions
21. LINIMENTS
• Nonalcoholic solutions of drugs in oil or alcoholic solutions of soap.
• Rubbed into the skin with friction
• Analgesics, counter irritants, astringent, emollient and antipruritic
22. CREAM:
Semisolid emulsions composed of both lipid and water
• Lipid in water-aqeous or vanishing cream
Water miscible cooling and soothing
• Water in oil- immiscible with water, more difficult to wash off,
Emollient lubricant and mildly occlusive
23. PASTES:
Semisolid preparations containing high proportion of finely powdered material
such as zinc oxide or starch
Protective paste: -Greasy ,water insoluble ,difficult to apply and remove.
-accurate localisation occlusive protective and hydrating
Drying paste: cooling paste
- mixture of powdered with liquid
- non greasy water miscible.
In comparison with ointments pastes are thicker, drier and more solid.
25. POWDERS
• Applied directly to skin
• Also known as dusting powders
• Reduce friction
• Absorb excessive moisture
26. POULTICES
• Wet solid masses of particles applied to
exudative lesions
• Bed sores,leg ulcers.
• May be heated before application
• Acts as cleansers and absorptive agents.
27. TRANSDERMAL DRUG DELIVERY SYSTEMS
Special methods of controlled
delivery of drugs into
circulation by topical route.
28. COLLODIONS:
Liquid preparation Consisting of cellulose nitrate in organic solvent.
• Evaporate easily to leave a flexible film.
• Most frequently used to apply salicylic and lactic acids to warts.
• May also be used as protectives ro seal minor cuts and abrasions.
• Easy to apply and water repellent.
• Inflammable.
29. MICROSPONGES:
Used as porous beads 10-25ùm in diameter to form a reservoir loaded with
drug
• Used for cosmetics and sunscreens
• Provide sustain release of drug while reducing irritation.
30. LIPOSOMES:
Aqueous phase surrounded by a lipid capsule
• Used as Penetration enhancing agents.
• Useful for reducing irritation from topical use of agents such as
tretinoin,benzoyl peroxide
• Reduces staining of skin and clothes from latter.
32. C. FREQUENCY:
• Maximize response while avoiding side effects.
• Excessive applications can lead to systemic effects
• Emollients-frequently
• Active preparations-OD / BID
• Pharmacological actions persists even after Drug has been wiped out
• Increasing interval between application is a effective way of tapering intensity
of treatment
• Rebound and tachyphylaxis
34. FINGER TIP UNIT
• Extending from the distal crease of
the forefinger to the ventral aspect
of the finger tip
• Approximately 0.5 gm.
• Covers an area of 300cm2.
49. Sunscreen =dose of UVB radiation producing minimal erythema with sunscreen
dose of UVB radiation producing minimal erythema without sunscreen
50. Humectants-
Compounds with high affinity for water.
Draw water into stratum corneum
Have emollient effect on dry skin
Eg: gelatin
glycerin
urea
Lacquer – liquid dissolved in alcohol that dries to form a hard protective
covering.
Emollients- derived from Latin word mollire which means to soften the skin.
51. CHOICE OF PREPARATION
Condition of skin Preparation of choice
Acute, inflamed,red,swollen, lesions with dischrge Lotions
Subacut, chronic, less inflamed Lotion, paste, cream.
Dry, scaly, thickened, lichenified Ointments, pastes
Generalized, widespread Eruptions Lotions
Soles Ointments
Hairy area Lotions
52. ADVICE TO PATIENT
• Where to use and where not to use
• How much to use
• When to use (timing)
• How to use
• Warning