Intranasal bilosomes in thermosensitive hydrogel: advancing desvenlafaxine succinate delivery for depression management

Depression, the second biggest cause of disability worldwide, is widespread. Many antidepressant medications, including Desvenlafaxine Succinate (D.V.S.), function by elevating neurotransmitter levels at the synapse through the inhibition of reabsorption by neurons. However, the effectiveness of these treatments is often limited by their inability to reach the brain using conventional administration methods. Bilosome-stabilized nanovesicles containing bile salts have drawn much interest because of their adaptability and versatility in various applications. This study aimed to address this issue by formulating intranasal bilosomes incorporated into a mucoadhesive in situ gel to deliver D.V.S. directly to the brain for depression treatment. The desvenlafaxine-loaded bilosomes were developed using a thin film hydration method based on the l-optimal design. They were intended to provide a more convenient route of administration for antidepressants, enhancing bioavailability and brain targeting through intranasal delivery. The study assessed the optimized bilosomes for particle size (311.21 +/- 0.42 nm), Zeta potential (-37.35 +/- 0.43)and encapsulation efficiency (99.53 +/- 0.41%) and further evaluated them in ex vivo and in vivo pharmacokinetics studies. Pharmacokinetic data reveal enhanced brain uptake compared to a free drug. A statistically optimized bilosome formulation was determined. The intranasal administration of mucoadhesive in situ gel containing desvenlafaxine succinate-loaded bilosomes facilitated direct nose-to-brain drug delivery, improving brain bioavailability.