Pulmonary Delivery of Anti-IgE: Rationale for Topical Delivery to the Airway
Topical administration of inhaled therapeutics is the current standard for the therapeutic management of asthma. Pressurized metered dose inhalers (pMDIs) or dry powder inhalers (DPIs) containing either steroids to combat inﬂammation or bronchodilators for rescue airway dilation are routinely used by the majority of asthma patients. The rationale for a topical course of treatment is obvious: to maximize the dose of the therapeutic agent to the target tissue site, the asthmatic lung, and to minimize systemic side effects. Other routes of administration, i.e., oral administration, are used for agents with low systemic toxicity (e.g., leukotriene antagonists) or where topical therapy does not adequately achieve desired therapeutic outcome (e.g., steroids). For proteins, oral therapy is not possible due to degradation of the therapeutic agent in the gastrointestinal tract.