Nasal spray sodium chloride or sea water), isotonic (0.9% sodium chloride) and hypotonic (0.65% sodium chloride). Isotonic solutions have the same salt concentration as the human body, whereas hypertonic solutions have a higher salt content and hypotonic solutions have a lower salt content. Isotonic saline nasal sprays are commonly used in infants and children to wash out the thick mucus from the nose in case of allergic rhinitis. Hypertonic solutions may be more useful at drawing moisture from the mucous membrane and relieving nasal congestion. Natural nasal sprays that include chemical complexes derived from plant sources such as ginger, capsaicin and tea-tree
Nasal administration suitable for potent drugs since only a limited volume can be sprayed into the nasal cavity. Drugs for continuous and frequent administration may be less suitable because of the risk of harmful long-term effects on the nasal epithelium. Nasal administration has also been associated with a high variability in the amount of drug absorbed. Upper airway infections may increase the variability as may the extent of sensory irritation of the nasal mucosa, differences in the amount of liquid spray that is swallowed and not kept in the nasal cavity and differences in the spray actuation process. However, the variability in