The Effectiveness of Oseltamivir Nanosuspension as a Promising Intranasal Mucoadhesive Spray for Management of Seasonal Influenza in Infected Patients

Introduction: Seasonal influenza can cause annual outbreaks of varying severity. Oseltamivir is an antiviral agent that has been used in influenza. In this study, the efficacy of intranasal oseltamivir nanosuspension was investigated in the treatment of seasonal influenza. Materials and Methods: Oseltamivir nanosuspensions were developed, evaluated, and administered to 101 patients who had seasonal influenza and were diagnosed by laboratory PCR. Patient groups were A, who received oseltamivir nasal nanosuspension twice daily plus paracetamol and antihistaminic for one week; B received oral oseltamivir plus paracetamol and antihistaminic for one week; and C (placebo), who received paracetamol and antihistaminic for one week. All the patients were followed up with. Results: The selected nanoformulation presented a small particle size (311.0 ± 15.18 nm) and acceptable stability. The duration of fever in group C was (3.50 ± 0.67) days, which is significantly longer than both groups A and B. The mean duration of rhinorrhea in group A was (2.25 ± 0.69) days versus (1.8 ± 0.6) days in group B. Duration of recovery was (3.78 ± 1.02) days in group A versus (3.70 ± 0.98) days in group B, without a significant difference. In group C, it was (7.13 ± 3.25) days, which is significantly longer than in the other groups. Discussion: The application of intranasal nanocarriers has been reported in previous studies for improved drug therapeutic efficacy. In recent research works published by our group, we found that a mucoadhesive nanosuspension nasal spray of ivermectin resulted in a significant reduction in the duration of recovery in patients with mild COVID-19 and a shorter duration of respiratory tract manifestations, especially anosmia, with rapid viral clearance. In this novel study, for the first time, a smaller dose of OST was incorporated to develop a nanosuspension and applied through the intranasal route, which resulted in rapid recovery from infection. Conclusion: Using nasal oseltamivir nanosuspension resulted in a significant reduction in the duration of full recovery in treated seasonal influenza patients, without systemic adverse effects.