Modified release tablets are medicines designed to release their active ingredients slowly over time instead of all at once. Common labels like ER SR CR and PR indicate how the drug behaves in the body. These small letters influence how often you take a dose how long the medicine stays effective and how your body responds. While doctors often treat these types as different and non interchangeable manufacturers and lab analysts say they mostly serve the same purpose to extend the effect of the drug. Understanding these codes helps patients make sense of their treatment and avoid confusion. In a country where pills are widely used but rarely understood knowing what these letters mean can shape better health outcomes.