Background: The use of intranasal drug delivery devices (IDDD) for the treatment of allergic rhinitis (AR) is frequent because they are simple, efficient, and safe, and mainly because they are perceived as low-risk. However, it is speculated that contact between the nasal mucosa and an IDDD may give rise to infections once the nose is colonized by bacteria, and there are currently no proper instructions for IDDD sanitization. The objective of this study was to evaluate the possibility of contamination of an IDDD for topical medication after simulating use in healthy individuals. Methods: The in vitro study consisted of 14 healthy individuals of both sexes, between the ages of 18 and 24 years. Samples were collected immediately after the opening of each IDDD and after simulating use by the subjects. Afterwards, the samples were deposited in tubes and kept in an incubator at 37 °C. After 48 hours, the samples were inoculated on Müller-Hinton agar. Qualitative analyses of the appearance of the samples were performed after 24 and 48 hours, and after 72 hours the presence or absence of bacteria was evaluated macroscopically. Results: After 24 hours of incubation, 21.4% (n = 3) of the samples presented with a turbid appearance and after 48h, 71% (n = 10) of the samples presented with a turbid appearance and positive bacterial growth. Conclusion: The results suggest that IDDDs for topical medications may be important sources of contamination or recontamination of the nasal mucosa of individuals who are being treated for upper respiratory tract conditions. A better understanding of the risks of re-using IDDDs after previous contact with the nasal mucosa will improve guidelines on hygiene procedures and prevention of related risks.