Dissolution and drug release tests measure the rate and extent to which a drug substance is released from a drug product under specified conditions. These tests are important quality control procedures that can be linked to how a drug performs in the body. Factors like the drug's properties, formulation ingredients, test medium, temperature, and apparatus used can affect dissolution and release. Common apparatuses include baskets, paddles, cylinders, and flow cells, each suited for different drug product types like tablets, capsules, or transdermal patches.