Metered dose inhalers (MDIs) are essential drug delivery devices primarily used in the management of respiratory disorders such as asthma and chronic obstructive pulmonary disease (COPD). These devices are designed to deliver a precise and consistent dose of medication directly into the lungs, facilitating rapid symptom relief and long-term control of the disease. Their compact size and portability, along with their ease of use, make MDIs a fundamental component of inhalation therapy in both acute and chronic respiratory care.