a great many of the important organic medicinal agents are either weak acids or weak bases, and their solubility depends to a large measure on the pH of the solvent These drugs react either with strong acids or strong bases to form water-soluble salts Table 12.2 presents the comparative solubilities of some typical examples of weak acids and weak bases and their salts
◼ A great many of the important organic medicinal agents are either weak acids or weak bases, and their solubility depends to a large measure on the pH of the solvent. ◼ These drugs react either with strong acids or strong bases to form water-soluble salts. ◼ Table 12.2 presents the comparative solubilities of some typical examples of weak acids and weak bases and their salts
a Commonly, salts of organic compounds are more soluble in water than are the corresponding organic bases Conversely, the organic bases are more soluble in organic solvents than the corresponding salt forms
◼ Commonly, salts of organic compounds are more soluble in water than are the corresponding organic bases. ◼ Conversely, the organic bases are more soluble in organic solvents than the corresponding salt forms
In most instances, especially for solutions to be taken orally, used ophthalmicallv, or injected, water is the preferred solvent. When water is used as the primary solvent, commonly an auxiliary solvent is also employed to augment the solvent action of water or to contribute to a product's chemical or physical stabilit ity
◼ In most instances, especially for solutions to be taken orally, used ophthalmically, or injected, water is the preferred solvent. ◼ When water is used as the primary solvent, commonly an auxiliary solvent is also employed to augment the solvent action of water or to contribute to a product’s chemical or physical stability
a Alcohol, glycerin, and propylene glycol, have been quite effective in contributing to the desired characteristics of pharmaceutical solutions and in maintaining their stability A number of fixed oils, such as corn oil, cottonseed oil, peanut oil, and sesame oil,are useful solvents, particularly in the preparation of oleaginous injections, and are recognized In the official compendia for this purpose
◼ Alcohol, glycerin, and propylene glycol, have been quite effective in contributing to the desired characteristics of pharmaceutical solutions and in maintaining their stability. ◼ A number of fixed oils, such as corn oil, cottonseed oil, peanut oil, and sesame oil, are useful solvents, particularly in the preparation of oleaginous injections, and are recognized in the official compendia for this purpose
2. Some solvents for liquid Preparations (1) Alcohol, USP: Ethyl Alcohol, Ethanol (2) Diluted Alcohol, NF (3 )Alcohol, Rubbing (4) Glycerin, USP(Glycerol) (5)Isopropyl Rubbing Alcohol (6)Propylene Glycol, USP ()Purified Water, USP
2. Some Solvents for Liquid Preparations (1) Alcohol, USP: Ethyl Alcohol, Ethanol (2) Diluted Alcohol, NF (3) Alcohol, Rubbing (4) Glycerin, USP (Glycerol) (5) Isopropyl Rubbing Alcohol (6) Propylene Glycol, USP (7) Purified Water, USP