——A homogeneous semi-solid external preparation made by mixing the raw material drug with a greasy or water-soluble matrix

Classification

——A uniform semi-solid preparation formed by dissolving or dispersing the raw material drug in an emulsion matrix

Features

——Semi-solid external preparations composed of a large amount of raw drug solid powder (generally more than 25%) evenly dispersed in a suitable matrix, which can be divided into water-containing gel pastes and fat pastes

Quality requirements

Even and delicate, no rough feeling when applied on skin

It has appropriate viscosity, is easy to apply on the skin or mucous membranes, does not melt, and is rarely affected by changes in the external environment.

Stable properties, no rancidity, odor, discoloration, hardening, etc. within the validity period

Has good safety, no irritation, allergies, or other adverse reactions

Skin ointments and creams used for large burns or severe injuries should be sterile

oily base

water soluble matrix

emulsifier

Antioxidants

bacteriostatic agent

transdermal absorption enhancer

Grinding method—a preparation method in which the fine powder of the drug is first ground into a fine paste with a small amount of base at room temperature, or the liquid is ground into a fine paste, and then the rest of the base is added in equal amounts and the mixture is evenly mixed.

Melting method - the matrix with a higher melting point is heated and melted, then the matrix with a lower melting point is added, and finally the liquid ingredients and drugs are added

emulsification method