is a viscous semisolid preparation used topically on a variety of body surfaces. These include the skin
and the mucus membranes
of the eye
(an eye ointment
, and nose
. An ointment may or may not be medicated.
The vehicle of an ointment is known as ointment base. The choice of a base depends upon the clinical indication for the ointment, and the different types of ointment bases are:
- Hydrocarbon bases. e.g. hard paraffin, soft paraffin.
- Absorption bases. e.g. wool fat, beewax.
- Water soluble bases. e.g. macrogols 200,300,400.
Properties which affect choice of an ointment base are:
- Solvent property
- Irritant effects
- Ease of application and removal
Methods of preparation of ointments
: In this finely subdivided insoluble medicaments are evenly distributed by grinding with a small amount of the base followed by dilution with gradually increasing amounts of the base.
Fusion: In this method the ingredients are melted together in descending order of their melting points and stirred to ensure homogenity
Topical medication forms
- Cream - Emulsion of oil and water in approximately equal proportions. Penetrates stratum corneum outer layer of skin well.
- Ointment - Combines oil (80%) and water (20%). Effective barrier against moisture loss.
- Gel - Liquefies upon contact with the skin.
- Paste - Combines three agents - oil, water, and powder; an ointment in which a powder is suspended.