DPI: A paradigm shift from nebulizers to dry powder inhalers

Drug delivery to pulmonary routes was once considered a challenging task. The emergence of inhalation therapy paved the way for drug delivery to the lungs. With various advances in inhalation therapy, modern-age drug delivery systems include nebulizers, pressurized metereddose inhalers, and dry powder inhalers (DPIs). The following review discusses the development stages of DPIs and also gives an insight into the current formulation aspects of DPI, animal models used for evaluation of drug release parameters, and the Anderson cascade impactor and its possible correlation with human respiratory tract with regards to drug deposition and particle size. Today, DPIs have brought about a revolution in drug delivery to lungs, and also offer more advantages with regards to consistency of dose delivered, stability, and ease of administration. Dry powders have been extensively used in the treatment of asthma and various other respiratory disorders. With the introduction of nanoformulations, a wide sector of researchers is working toward developing DPIs that may be used to target diseases like lung cancer.