The plaster (Emplastrum) is a dosage form that is used exclusively externally. The plaster at room temperature usually has a dense consistency, and at body temperature it softens, but does not melt, becomes sticky, adheres tightly to the skin and does not irritate it. Lead salts of fatty acids, fats, wax, resins, rubber, paraffin, etc., as well as active medicinal substances (for example, salicylic acid, mercury , acriquine) can be included in the patch. According to their purpose, the patches are divided into: 1) epidermal, used to protect the affected skin from dust, dirt, infection, to close skin defects, to approach the edges of wounds, to protect the skin from damage, to strengthen the dressing, etc. (sticky adhesive); 2) endermatic, containing medicinal substances that have a local effect on diseased skin (corn plaster, epilin plaster ); 3) diadermatous, having in its composition substances with resorptive action (mercury patch). The adhesives also include adhesives and varnishes, which form a dense protective film after drying. The action of the patches is similar to the action of ointments, but due to the large sealing, the plaster warms the skin faster and stronger, loosens the stratum corneum, causes the skin vessels to expand and thus contributes to a deeper effect of the medicinal substances that make up its composition. They make patches in pharmaceutical plants.
Plaster (lat. Emplastrum) - dosage form for external use, having a dense consistency at room temperature. The plaster melts or softens at body temperature and adheres firmly to the skin. They produce adhesives in pharmaceutical factories and plants. Some patches can be prepared in pharmacies. The composition of the patch includes a variety of substances: lead salts of fatty acids, fats, waxes, resins and rubber, paraffin, etc. Often, these substances are added drugs that have a specific effect. For medical purposes, patches are divided into: 1) epidermal patches used to strengthen the dressing, to close skin defects (adhesive plaster), or patches, which medicinal substances have a local effect (a corn plaster); 2) diadermatics, which include substances that have a resorptive effect (for example, a mercury plaster); currently rarely used. Skin adhesives and varnishes, which form an elastic film after evaporation (collodion, cleol, collosilicate, BF-6 glue, etc.), also belong to patches.