Preparation and in-vitro evaluation of an in-situ gel forming of chitosan-based morphine formulation as an intranasaladministrationRunning title: An intranasal in-situ gel forming of morphine

Intranasal delivery through the epithelium of nose is an interesting and useful idea because it has a fast onset of effect with any metabolism in liver and digestive system, also it is user-friendly, noninvasive and without pain. In this study, we aimed to prepare and evaluate an in-situ gel forming of chitosan-based morphine formulation as an intranasal administration in vitro.

In this project, the in-situ gel forming of morphine-loaded chitosan formulation was firstly prepared and finally its physicochemical properties was determined in order to achieve the technology of a gel-forming formulation for morphine nasal delivery.

The final prepared formulation was in the form of sol in room temperature; while, it was transmitted to the gel form at 37 °C and subsequently returned to the sol form after decreasing temperature. The obtained results of burst release test showed a sustained release of morphine from the polymeric matrix of chitosan. Additionally, the formulation showed that it could be sprayed in nostril with no toxicity.

The biodegradable and biocompatible intranasal form of morphine could be gelled in the shortest possible time before leaving the nose at a temperature of 34 °C. Also, based on the release pattern of morphine, morphine could slowly induce its analgesic effects.