Creams: Types, Advantages, Disadvantages, Pharmaceutics Notes PDF
Creams are viscous liquid or semisolid emulsions intended for application to the skin i.e. for external use
Creams are of two types, aqueous creams and oily creams.
In the case of aqueous creams the emulsions are oil-in-water type and in the case of oily creams emulsions are of water-in-oil type.
Due to the presence of water-soluble bases they can be easily removed from the skin.
The aqueous creams have a tendency to grow bacterial and mould growth, therefore a preservative must be added in their formulation.
e.g. cetomacrogol cream, cetrimide cream, hydrocortisone cream, zinc cream BPC.
1. Creams are more acceptable to the patients because they are less greasy and are easier to apply.
2. They interfere less with skin functions.
3. o/w type of creams (superior to w/o type) can be rubbed onto the skin more readily and are easily removed by washing. w/o can be spread more evenly.
4. o/w type of cream are less likely to soil clothes.
5. Evaporation of water from o/w type of cream causes a cooling sensation.
6. o/w creams absorb the discharges from the wound (liquid exudate) very quickly.
7. w/o creams (e.g. cold creams) restricts evaporation from the skin, it can be used on non-weeping surfaces to prevent dehydration ( in the dry season), restore suppleness (softness)
Creams like cold cream restrict evaporation from the skin, it can be used on non-weeping surfaces to prevent dehydration ( in dry season), restore suppleness (softness) – this property is said to be ‘emollient’
1. Since it is a semisolid preparation and contains oil in large amounts, some of which are inedible, hence creams are not used for internal use. Basically creams are meant for application onto the skin.
2. The aqueous phase is prone to the growth of moulds and bacteria hence preservatives should be used.
3. Sometimes rancidification of oils take place.