Management of Skin conditions
The vehicle used in skin preparations will affect the hydration of the skin, has a mild anti-inflammatory effect and aids the penetration of the active drug.
Ointments (greasy preparations) are often preferable to creams in most circumstances as they contain fewer skin sensitisers, are more hydrating and there is better penetration of the active ingredients. However, they are often less cosmetically acceptable. Patient preference may necessitate a combination of products, e.g. cream during the day, ointment at night.
Creams are emulsions of oil and water and are generally well absorbed into the skin. Creams are suitable for normal or moist skin; they are cosmetically acceptable but may contain potentially sensitising preservatives. Creams need to be applied more frequently and generously to have the same effect as ointment.
Gels consist of active ingredients in suitable hydrophilic and hydrophobic bases. They generally have a high water content.
Lotions are liquid and have a cooling effect. They are preferred to ointments or creams for application over a hairy area or on wet rashes.
Pastes are stiff preparations containing a high proportion of finely powdered solids such as zinc oxide and starch suspended in an ointment.
Possible contact sensitivity to preservatives or antiseptics is the reason for the range of topical agents.
Bath additives: there is inconclusive evidence for efficacy.
Suitable quantities of preparations to be prescribed for specific areas of the body
These amounts are usually suitable for an adult for twice a day application for one week.
|Creams & ointments||Lotions|
|Face||15g - 30g||100mL|
|Both hands||25g - 50g||200mL|
|Scalp||50g - 100g||200mL|
|Both arms||100g - 200g||200mL|
|Both legs||100g - 200g||200mL|
|Groin & genitalia||15g - 25g||100mL|