Advantages of topical treatments

• Direct application
• Reduced systemic effects

Disadvantages of topical treatments

• Time consuming
• Correct dosage can be difficult
• Messy to use

Bases or vehicles

• Drugs used on the skin are dissolved in bases or vehicles e.g. gels, creams, ointments

They act to cool and moisturise the skin

Generally non greasy and cosmetically acceptable | | Ointment | Semi solid grease (oil) which have a high lipid content but no preservatives

They are occlusive and limit transdermal water loss

They are greasy and less cosmetically acceptable | | Lotion | Liquid formulations of medications suspended in alcohol or water, with suspension in alcohol causing stinging

Generally used to treat dry, hair-bearing areas such as the scalp | | Gels | Semi solid thickened aqueous solutions

Used to treat hair-bearing areas and the face | | Pastes | Semi solids made up of finely powdered minerals such as zinc oxide

They cool and hydrate the skin, often used in cooling bandages

Generally quite difficult to apply | | Foams | Colloid with two/three phases

Usually with hydrophobic liquid in continuous phase with foaming agent dispersed in gaseous phase

Increased penetration of active agents

Can spread easily over large areas of skin and do not leave a greasy/oily film |

Emollients

• Ointments, creams, lotions and gels
• Enhance rehydration of epidermis - used in all dry/scaly conditions especially eczema
  • Breaks the itch-scratch cycle to allow the skin to restore its barrier function
• Emollient such as emulsifying ointment can be used as soap substitutes
• Avoid emollients containing SLS in 'leave-on' products
• Some emollients contain urea - urea attracts and holds water in the stratum corneum which compensates for the reduced levels of natural moisturising factor (NMF)

Cost of emollients

• Non-propriety e.g. liquid paraffin - cheaper
• Propriety - more expensive but are often more cosmetically acceptable which is important for compliance

Wet wrap therapy