Inhalation drug delivery (IDD) is an effective approach for treating respiratory diseases, including asthma, cystic fibrosis, lung cancer, and chronic obstructive pulmonary diseases. The advantages of inhalation drug delivery (IDD) include lowering the dose and dosing frequency, overcoming drug resistance, increasing in drug’s effectiveness by applying it directly to the expected site of disease, and lowering the systemic toxicities of the drug. Inadequate instruction and training in the use of the inhalation device to control the actuation and aerosol inhalation may lead to the absence of intended clinical outcomes as well as issues with efficacy or any negative drug effects. There have been advances in technology-driven novel strategies in the formulation and development of aerosols, nebulizers, metered dose inhalers, and dry powder inhalers to encounter the problems associated with coordination skills, dosing frequency, and safety. Formulation advancement involves microparticles and nanomedicine-based approaches for IDD. However, the novel advance designs, structures, and functions of IDD devices make them more prominent, precise, and effective. The in vitro, in vivo, and ex vivo models that strengthen and check the possible efficacy of the developed IDD are discussed in the chapter. This chapter gives insight into the advancement of these IDD, novel formulation approaches, their evaluation through various preclinical models, and their benefits over previous IDD.