Development of Abelmoschus esculentus (Okra)-Based Mucoadhesive Gel for Nasal Delivery of Rizatriptan Benzoate

Purpose: To develop a safe mucoadhesive gel for nasal drug delivery using okra polysaccharide. Methods: Rizatriptan benzoate nasal gel was developed using natural polysaccharide obtained from the Abelmoschus esculentus. The gel formulation was characterized for pH, viscosity, mucoadhesion, and in vitro permeation. Permeation parameters obtained include drug flux (j), permeation coefficient (kP) and lag time (tL). The effect of sodium thioglycollate and sodium taurocholate on permeation of the gel formulations was evaluated using excised goat nasal mucosa. Results: Okra gel formulation showed good properties in terms of pH, viscosity and mucoadhesion. The drug was able to permeate through the goat nasal mucosa within 255 min. The test okra nasal gel, with and without enhancer, showed superior permeation properties to gels prepared with synthetic polymers hydroxylpropyl methylcellulose (HPMC) and sodium carboxymethyl cellulose (NaCMC). For example, drug flux (j) of okra nasal gel formulation and gel formulations made with HPMC and NaCMC was 134.8, 120.9 and 84.8, respectively. Conclusion: Okra mucilage is a promising natural and safe gel former that can be developed to serve as an alternative to currently used synthetic gel formers for nasal drug delivery.