Medicinal Suspensions

Medicinal Suspensions, liquid medicinal forms (for internal and external use, for subcutaneous injection, and for enemas) to which powdered insoluble solid substances have been added. The latter, when the liquid is shaken, remain suspended for some time and then, depending on the properties of the substances themselves and the liquid in which they are located, settle to the bottom more or less quickly. Among the most frequently prescribed medicinal suspensions (suspensions-Mixturae agitandae) are aqueous mixtures or emulsions to which are added: camphor, bismuth salts (nitrate, carbonate, and salicylate), salol, naphthalene, tanalbin, benzonaftol, and sulfur (the latter-for external use). Most of these substances are first triturated in a mortar with the addition of a small amount of alcohol (e.g., for camphor), an equal amount of gum arabic or a little glycerin, and always with the gradual addition of the liquid to which these substances are added. Insoluble medicinal substances remain suspended for a longer time and are therefore more accurately dosed when mixed with some mucilaginous liquid or emulsion, for example, with gum arabic mucilage, salep, or starch decoction (the latter-for enemas). In addition to those mentioned, antiluetic suspensions for subcutaneous injections are widely used: mercury salicylate in vaseline oil and insoluble bismuth compounds in almond oil (e.g., bibhinol, bismutol, etc.). All medicinal suspensions should be dispensed from pharmacies with the inscription: "Shake before use."