Discover how enteric coating works by looking at the design and function of a protective layer that is applied to a dosage form. In simple terms, an enteric coating is a thin polymer shell placed around a solid core, engineered to respond to the environment as it moves through the digestive system. The focus here is on the mechanism that determines where and when the core releases its contents, driven by chemistry and materials science rather than by habit or dosage choice. How enteric coating works is driven by the properties of the coating material. Many coatings use pH-sensitive polymers that resist water and remain intact in highly acidic conditions, such as those found in the upper digestive tract. When the environment becomes less acidic, the polymer dissolves or becomes permeable, allowing the core to release its contents. The specific polymer, its plasticizers, film thickness, and any additives all influence the timing of dissolution and the resulting release profile. Application and processing details are important for achieving consistent performance. The coating is typically applied to the core through a controlled spray process, followed by drying and curing to form a uniform film. Critical quality attributes include even thickness, the absence of defects like pinholes, and the film’s ability to resist mechanical handling during manufacturing and packaging. Each parameter—from solvent choice to coating temperature—contributes to how the coating behaves in different environments. Evaluation and testing play key roles in understanding how enteric coating works. Dissolution testing simulates acidic and neutral/alkaline conditions to confirm that the coating remains intact at low pH and begins to dissolve at higher pH levels. Additional tests assess mechanical durability, environmental stability, and compatibility with the core material. Together, these assessments illuminate the science behind how enteric coating works and how formulation choices shape its performance.