The division of ointments according to the place of application is mainly of medical importance, although to some extent determines the choice of technological operations. For example, ointments applied to mucous membranes are particularly sensitive to microorganisms, therefore, they must be prepared under aseptic conditions. Obviously, the dispersibility of drugs in ocular ointments should be much higher than in dermatologic ointments. In addition, the choice of ointment base should be carried out taking into account the place of application of the ointment. Classification of ointments by the nature of action. By the nature and speed of the effect on the body, ointments are divided into two groups: Ointments that have a local (local) effect directly on the upper epidermis layer of the skin or the surface of the mucous membrane. Examples are ointments dermatolovoy, zinc, xeroform, used in the treatment of dermatitis, eczema and other skin diseases. Ointments resorptive action, deeply penetrating into the skin or mucous membrane, reaching the bloodstream and lymph and having a general effect on the whole body or on individual organs. Nitrong ointment is an example.

It contains 2% nitroglycerin oil solution and is used for prevention of angina attacks. The ointment is applied to the skin of the chest, abdomen or arm, spread a thin layer and cover with impermeable material (polyethylene film) for better absorption. The effect usually comes in 30-40 minutes and lasts up to 3-5 hours. Classification of ointments by type of ointment bases. The following groups of ointments can be distinguished by the type of bases: hydrophobic ointments; hydrophobic absorbent ointments; hydrophilic ointments. Classification of ointments according to the degree of affinity of the properties of drug substances and ointment bases. In the form of ointments, currently used drugs belonging to almost all pharmacological groups. The most widely used are antiseptics, sulfonamides, hormones and their analogs, antibiotics, vitamins, anesthetics and agents for the treatment of fungal diseases. Being substances of organic or inorganic origin, they have different chemical nature (metal oxides and their salts, acids and bases, esters, etc.), which determines their aggregate state and physicochemical properties.