The present invention provides a controlled-release composition which provides a therapeutically effective plasma concentration of N-acetylcysteine over prolonged period of time. The present invention also includes the use of the controlled-release composition, either alone or in combination with at least one additional active agent, for reduction of vascular inflammation marker and treatment of diseases, conditions, and/or symptoms associated with systemic and/or vascular inflammation in a patient. Furthermore, the present invention provides a process of making granules comprising N-acetylcysteine, or a salt, solvate, prodrug, and/or analog thereof.