What is the term for the concentration of a chemical in a pharmaceutical solution?

The term that refers to the concentration of a chemical in a pharmaceutical solution is known as "solubility." Solubility is a measure of how much of a given chemical can dissolve in a solvent at a specific temperature and pressure. In pharmaceuticals, understanding solubility is crucial because it affects the drug's formulation, absorption, and overall effectiveness in the body.

Tonicity, on the other hand, relates to the osmotic pressure gradients between two solutions and how they affect cell volume. Viscosity is a measure of a fluid's resistance to flow, which is not directly related to concentration but can impact the ease of administration of a solution. Stability refers to the ability of a drug to maintain its chemical integrity and activity over time under specific conditions. Thus, the term that accurately describes the concentration of a chemical in a solution is solubility.