Nasal In Situ Hydrogels: A Boon For Anti-Emetic Drug Delivery.

Nasal route presents an alternative avenue for achieving local or systemic drug effects owing to its non-invasiveness, expansive surface area, rapid drug absorption, and circumvention of first-pass effect. It offers a promising route for brain targeting too, as it bypasses the blood-brain barrier, thus facilitating direct nose to brain drug delivery. However, traditional routes of administering anti-emetic drugs, primarily oral or parenteral, suffer from drawbacks like poor patient compliance and low drug bioavailability. The nasal route is a favorable alternative, albeit limited by the short retention time due to mucociliary clearance. This can be overcome by application of in situ gelling systems that undergo gelation within the nasal cavity in response to physiological cues, thereby prolonging drug retention and enhancing bioavailability. This facilitates dose reduction, reduced frequency and controlled drug release, thereby improving patient acceptance. Presently, various formulations utilizing intranasal in situ gelling approaches are under development for anti-emetic drugs. These formulations employ stimuli-responsive mechanisms such as thermosensitivity, ion responsiveness, and pH sensitivity for in situ gel formation, with a focus on employing specific polymers tailored to these stimuli. The article highlights importance of nasal delivery of anti-emetic drugs and studies done on this topic till date. Intranasal in situ gelling systems hold promise due to their ease of administration, prolonged nasal retention, improved patient compliance and enhanced bioavailability, positioning them as efficient alternatives to conventional routes of administration.