Pharmacology Flashcards
(27 cards)
What are the two routes a drug can take to cross the skin?
Transcellular and intercellular.
What are the three depths of drug administration through the skin?
Topical- Local effect
Transdermal- Systemic effects
Subcutaneous- Systemic effects
What is the major barrier to drugs penetrating the skin?
Stratum corneum- keratin layer
Out of transcellular and intercellular which route is most common?
Intercellular
What must a drug be to pass though the intercellular route?
LMW and lipophilic
List the 7 forms topical treatment can take.
Ointments Creams Gels Lotions Pastes Powders Foams
What factors must be considered when picking a vehicle?
Skin condition
Drug
Patient preferences
Why is there an excess of undissolved drug?
As dissolved drug is absorbed the undissolved drug becomes dissolved thus giving a steady supply for a long time.
How can the absorption of drugs be increased topically.
Skin hydration
Inclusion of excipients to increase solubility.
Drug salt form
Choice of vehicle
What are the advantages of topical treatments?
Direct application to required area
Reduced systemic effect
What are the disadvantages of topical treatments?
Time consuming
Dosing difficulties
Messy
What is a cream?
Semisolid emulsion of oil in water containing emulsifiers and preservatives. Non greasy with high water content.
What is an ointment?
Semisolid grease or oil with no preservatives. Good for preventing water loss.
What is a lotion?
Suspension of drug in water or alcohol. Treat hairy areas.
What is a gel?
Semi-solid aqueous solution containing high molecular weight polymers. Treat face and hairy areas.
What is a paste?
Semisolid grease containing fine powdered materials such as ZnO. Use for cooling and soothing.
What is an emollient?
A product designed to trap water and rehydrate the skin. Apply after wash and in direction of hair.
What are wet wraps?
Wetted bandages put on over topical treatment to prevent scratching and provide soothing.
What effects do topical steroids have?
Vasoconstriction
Anti-inflammatory
Antiproliferative
Give an example of a mild steroid.
1% Hydrocortisone
Give an example of a moderate steroid.
0.05% Modrasone Clobetasone Butyrate.
Give an example of a potent steroid.
0.1% Mometasone Betamathasone Valerate
Give an example of a very potent steroid.
0.1% Clobetasol Proprionate.
What are some side effects of topical steroids?
Thinning of skin
Purpura
Cushings syndrome
Rebound inflammation
