Formulation And Evaluation of Nasal In-Situ Gel of Montelukast Sodium

The present study was aimed at the development and evaluation of an in situ nasal gel formulation of Montelukast Sodium Six formulations (F1–F6) of Montelukast Sodium in situ nasal gel were prepared using varying concentrations of chitosan and Carbopol 934 to optimize gel strength, viscosity, Mucoadhesion, and drug release. All formulations were subjected to comprehensive evaluation. pH of All batches were within the range of 5.7–5.9, suitable for nasal application. Drug Content study showed high uniformity was observed (98.3–99.5%), with F3 showing the highest content (99.5 ± 0.8%).Viscosity was found in ranged from 150 cps (F1) to 290 cps (F6); F3 (210 cps) provided the most balanced flow properties. Gelling Capacity: F3 and F4 showed +++ (instant and strong gelation), making them suitable for rapid in situ transformation upon nasal administration. Gel Strength: F3 exhibited adequate strength (38.9 ± 1.7 sec) to retain the formulation at the absorption site. Mucoadhesive Strength showed that increased with polymer content. F3 showed a favorable value (1382 ± 50 dyne/cm²), promoting better retention in the nasal cavity. These results collectively established F3 as the optimized formulation, offering ideal clarity, pH, drug content, gelling behavior, and mucoadhesion. The in vitro diffusion study using a Franz diffusion cell with goat nasal mucosa demonstrated varying drug release profiles; F1 released 98.24 ± 1.34% in 5 hours due to lower viscosity. F6 showed the slowest release (76.92 ± 1.88% at 6 hours) due to a dense polymeric network. F3 demonstrated controlled release the optimized formulation F3 was evaluated for 3-month stability under ICH conditions. The results confirmed that the formulation retained physical and chemical stability over time and is suitable for long-term storage and usage.