Sustained-release (SR) tablet is a type of dosage form in which the drug is released over an extended period of time, typically several hours to several days. This is achieved by incorporating the drug into a matrix or coating that controls the rate of drug release. The goal of sustained-release formulations is to maintain a constant drug level in the body, reducing the frequency of dosing and improving patient compliance. Examples of drugs delivered via SR tablets include pain medications, antidepressants, and cardiovascular drugs. It's important to note that SR tablets should not be crushed or chewed as this can alter the intended release pattern and lead to toxicity.