The major part of the approximately 150 cm 2 surface in the human nasal cavity is covered by respiratory epithelium, across which systemic drug absorption can be achieved. The olfactory epithelium is situated in the upper posterior part and covers approximately 10 cm 2 of the human nasal cavity. The nerve cells of the olfactory epithelium project into the olfactory bulb of the brain, which provides a direct connection between the brain and the external environment. The transfer of drugs to the brain from the blood circulation is normally hindered by the blood–brain barrier (BBB), which is virtually impermeable to passive diffusion of all but small, lipophilic substances. However, if drug substances can be transferred along the olfactory nerve cells, they can bypass the BBB and enter the brain directly.,  
Mortuaire, G., de Gabory, L., François, M., Massé, G., Bloch, F., Brion, N., ... Serrano, E. Rebound congestion and rhinitis medicamentosa: Nasal decongestants in clinical practice. (2013, June 1). Critical review of the literature by a medical panel. European Annals of Otorhinolaryngology, Head and Neck Diseases , 130(3), 137-144. Retrieved from https:///#!/content/playContent/1--S1879729612001378?returnurl=http:%2F%%2Fretrieve%2Fpii%2FS1879729612001378%3Fshowall%3Dtrue&referrer=https:%2F%2F .
A wart is a small growth on the skin caused by the human papilloma virus, HPV. Warts are contagious and can easily be transferred to other people and other parts of the body. As many as 10% of the total population are suffering from warts and among children, as many as 1 in 3 are affected. EndWarts is a powerful wart treatment, which effectively dries out warts on hands, feet, elbows and knees. It contains formic acid and the unique solution penetrates the wart deep down to the roots and helps the body to effectively dry out and reject the wart. EndWarts is easy to use and the treatment only takes a few seconds once a week until the wart is gone. The solution is absorbed directly into the wart and leaves no scars. EndWarts is now also available in a convenient pen device for a safe and precise application. Further life cycle projects are ongoing to strengthen the brand and the position in the market.