The Science is pretty simple:
The nose is lined with a skin we call the mucus membranes. These are the structures that catch the majority of the bugs, bacteria,viruses, dust that we breath in every day. The bugs get caught on the membranes and the fine microscopic hairs that cover them (cilia).
Dry air causes the mucus membranes in the nasal passages to dry out making them swell.
Then the cilia shrink and stop moving which gives that stuffed up feeling.
Swollen membranes and poor cilia means that a major part of the body's defences against bacteria and viruses is reduced and made less effective.
Nisita protects the cilia and mucus membranes from these damaging effects by providing an additional barrier against tissue dehydration and particle/virus damage. This provides protection against disease and restores nasal comfort.