Rhinitis, mucociliary clearance

Direct toxic effects such as irritation, inflammation, or increased permeability will bring about symptoms such as the sneeze reflex, nasal discomfort, and hypersecretion with the possibility of underlying pathological changes such as squamous metaplasia, cilia erosion, plasma exudation, epithelial necrosis, inflammatory remodeling, or neutrophil accumulation. Indirect adverse effects can also occur and any alteration to normal nasal homeostasis should be avoided. For example, a reduction in mucociliary clearance can cause rhinitis, sinusitis, and an increased susceptibility to airway infections, and consequently ciliary movement should not be altered by any nasal medication. In the context of absorption enhancers, the rate and extent of recovery of normal nasal epithelial function after nasal administration is a prime consideration. 

The rate of mucociliary clearance can be affected by the pathophysiological condition of the nasal cavity and this will also affect the rate of clearance of administered drag. Such conditions include rhinitis, the common cold, hayfever, sinusitis, asthma, nasal polyposis, Sjogren s and Kartagener s syndromes. In addition, environmental factors such as humidity, temperature and pollution can also affect the rate of nasal clearance. 

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