In-Situ Nasal Gel-A Review

Over the few decades, advances in the in-situ gel technologies have spurred development in many medical and biomedical applications including controlled drug delivery. Many Novel In-Situ gel based delivery matrices have been designed and fabricated to fulfill the ever increasing needs of the pharmaceutical and medical fields. In-Situ gel drug delivery systems are sol form before administration in the body, but once administered, undergo gelation in-situ, to form gel. The formation of gel depends on factors like temperature modulation, pH change, presence of ions from which drug get released in sustained and controlled manner. In-Situ gels exhibit the properties of linear polymer solutions outside the body (allowing easy injection) but gel In-Situ within the body, providing prolonged drug release profiles. Recently, it has been shown that many drugs have better bioavailability by nasal route than the oral route. This has been attributed to reach vasculature and highly permeable structure of nasal mucosa coupled with avoidance of Hepatic-first pass metabolism. Thus this review focuses on nasal drug delivery, various aspects of nasal anatomy and physiology, nasal absorption mechanism, and In-Situ gels evaluations.