A semisolid preparation usually containing medicinal substances and intended for external application. O. bases used as vehicles fall into four general classes: 1) Hydrocarbon bases (oleaginous o. bases) keep medicaments in prolonged contact with the skin, act as occlusive dressings, and are used chiefly for emollient effects. 2) Absorption bases either permit the incorporation of aqueous solutions with the formation of a water-in-oil emulsion or are water-in-oil emulsions that permit the incorporation of additional quantities of aqueous solutions; such bases permit better absorption of some medicaments and are useful as emollients. 3) Water-removable bases (creams) are oil-in-water emulsions containing petrolatum, anhydrous lanolin, or waxes; they may be washed from the skin with water, and are thus more acceptable for cosmetic reasons; they favor absorption of serous discharges in dermatological conditions. 4) Water-soluble bases (greaseless ointment bases) contain only water-soluble substances. See also cerate.salve, uncture, unguent; [O. Fr. oignement; L. unguo, pp. unctus, to smear]
blue o. a grease-based o. containing 20% finely divided metallic mercury, formerly widely used for local application to the skin for the destruction of body lice. Risk is associated with transdermal absorption of mercury and a local dermatitis.mild mercurial ointment;
eye o. ophthalmic o
hydrophilic o. an o. base consisting of 25% each of white petrolatum and stearyl alcohol, 12% propyl glycol emulsified in 37% water by 1% of lauryl sulfate; preserved with paraben. Suitable for the incorporation of numerous drugs intended for local application; a washable o. base.
mild mercurial ointment blue o
ophthalmic o. a special o. for application to the eye that must be free from particles and must be nonirritating to the eye.eye o., oculentum;
Browse Medical References: