Biomedical Engineering Reference
In-Depth Information
formulation and the other end is inserted in one of the nostrils (Figure 17).
When the patient blows through the mouthpiece, the soft palate of the patient
closes and a valve within the device opens. The air flow through the device
creates turbulence which disperses the powder and directs it towards the nasal
cavity. The closure of soft palate as a result of exhaling air through the device
minimizes access of small particles to the lower respiratory regions. Thus, the
particles will find their way to the other nostril, which maximizes the aerosol
deposition in the nasal cavities with only minimal deposition in the lower
respiratory regions (Figure 17) (Djupesland et al., 2004; Djupesland and
Watts, 2005).
(Adapted from: Djupesland and Watts, 2005).
Figure 17. (a) OptiNose is a V-shaped nasal device loaded with powdered formulation,
with one end inserted in the nose and the smaller end inserted in the mouth. When
patient blows in, the soft palate closes and a valve within the device opens, resulting in
powder dispersion and deposition throughout the nasal cavity. (b) Because the soft
palate is closed the powder dispersion will make a ―U turn‖ movement towards the
other nostril instead of moving to the lower respiratory regions. This movement is
described as ―bidirectional‖.
It has been reported that deposition in the lower regions of the respiratory
tract did not exceed 5.6% of the dose using the OptiNose compared to ~ 4
times higher values using a nasal nebulizer (Djupesland et al., 2004). This
delivery approach permits the particles to access the other nostril (Figure 17)
and may enhance the targeting of drugs to the olfactory region of the nose and
hence the drug delivery to the central nervous system. There are ongoing
investigations on the suitability of OptiNose in delivery of sumatriptan for
migraine treatment (Djupesland and Hafner, 2004; Djupesland and Watts,
2005; Luthringer et al., 2008). Moreover, the OptiNose has been suggested to
target the adenoid region in the nasal region for vaccination (Djupesland and
Hafner, 2004) and for targeting the parasinuses (Djupesland et al., 2006).
