Intermolecular forces of attraction
Application of pharmaceutical principles to drug dosage forms is illust rated when drug dosage forms are categorized according to their physical state, degree of heterogeneity, and chemical composition. The usual relevant states of matter are gases, liquids, and solids. Intermolecular forces of attraction are weakest in gases and strongest in solids. Conversions from one physical state to another can involve simply overcoming intermolecular forces of attraction by adding energy (heat) . Chemical composition can have a dramatic effect on physicochemical properties and behavior. For this reason, it is necessary to distinguish between polymers, or macromolecules, and more conventional ( i .e., smaller) molecules, or micromolecules.
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