A Dry Powder Inhaler (DPI) is a device that inhales dry powdered medication into the lungs. DPIs are frequently used to treat respiratory conditions like COPD, bronchitis, and asthma. In recent years, interest in DPI as an effective and ecologically friendly method of medication delivery to the lung has increased. Only an effective metering mechanism, a well-chosen device, and an appropriate powder formulation will allow a dry powder inhaler to achieve these objectives. The three main categories are nebulizer, pMDI, and DPI. DPIs, which administer medication to the lungs in the form of a dry powder, are an alternative to pMDI. To ensure that the patient receives the same dose each time at a varied airflow rate, API particles must be present in the size range of 1 to 10m.The use of pressurized metered dosage inhalers (MDIs) has been around for a while to treat lung conditions like asthma and chronic obstructive pulmonary disease. MDIs rely on the propellant, which makes up the majority of the MDI formulation, to atomize medication and excipients droplets, which should ideally deposit in the lungs. The methods of formulating for MDI drug delivery underwent significant improvements during the phase-out of chlorofluorocarbon propellants and the introduction of hydrofluoroalkane propellants, which are more environmentally friendly. There was also a greater understanding of the effects of formulation variables on product performance. This paper provides an overview of the difficulties involved in creating MDIs as solution or suspension products containing one or more medications, taking into account the physicochemical characteristics of various excipients and how their addition may affect the MDI's overall product performance.