What is a common diluent used for reconstituting medications?

Sterile water is widely recognized as a common diluent used for reconstituting medications because it is free from contaminants and does not introduce any additional substances that could interfere with the medication's effectiveness or stability. When medications come in a powdered form, they often need to be dissolved in a liquid to be administered, and sterile water is ideal because it is designed for injection and does not contain any additives that could cause adverse reactions.

Other options like alcohol are typically not used for reconstitution as they can cause irritation and may not be compatible with many medications. Glycerin is a thick, syrupy liquid often used as a vehicle for oral medications but is less suited for injection purposes. Propylene glycol, while it can serve as a solvent, is generally not preferred for reconstituting most injectable medications due to its relatively high viscosity and potential for toxicity at higher concentrations. Thus, sterile water stands out as the safest and most effective option for reconstituting a wide range of medications.