Nasal In Situ Gel: Novel Approach for Nasal Drug Delivery

Abstract

Nasal delivery is an alternative to oral or parenteral administration due to certain limitations such as absorption of the drug, drug targeting to particular organs can cause a problem for administration through oral route. The nasal route has also been successfully used for bypassing the blood-brain barrier and afterword delivering drug molecules to the central nervous system. Also, lag time related to oral drug delivery is reduces by this route and offers noninvasiveness, self-medication, patient comfort, and patient compliance. Extend drug delivery can be attained by different new dosage forms like in situ gel. In situ formulations are drug delivery systems. The in-situ gelling system is a process in which the solution forms of a gel before administration in the body, but once administrated, it undergoes gelation in-situ, to form a gel. In situ gelling system becomes very popular nowadays because of their several advantages over conventional drug delivery systems like a sustained and prolonged release of a drug, reduced Frequency of administration, improved patient compliance and comfort. Approaches towards the various formulation of in-situ gel concerning temperature, pH, and physicochemical conditions. The in situ gel-forming polymeric formulations offer several advantages like sustained and prolonged action reduced Frequency of administration, in comparison to conventional drug delivery systems. From a manufacturing point of view, the production of such systems is less complex and thus lowers the investment and manufacturing cost. Various evaluation parameters are considered during the preparation of In-Situ gel.
 Keywords: Nasal Drug Delivery, In Situ gel, gelation, polymers, etc

Improving Drug Delivery for Alzheimer’s Disease Through Nose-to-Brain Delivery Using Nanoemulsions, Nanostructured Lipid Carriers (NLC) and in situ Hydrogels

“…Hydrogel formulations with suitable rheological properties are difficult to administer using a standard nasal spray device, although this can be overcome using in situ gelation. 100 Furthermore, bioadhesive polymers can be used to increase the aptitude of formulations for nose-to-brain delivery. They can allow a more sustained release of the drug, decreasing the number of doses administered and improving the patient’s adherence to the treatment.…”

“…In situ hydrogels are formed by stimulus-sensitive polymers that, once administered to the body, undergo an in situ gelation, forming a hydrogel. 100 , 101 Stimulus-sensitive polymers are classified according to the type of stimulus to which they respond: 102 , 103 i) polymers that respond to biological stimuli (enzymes and biomolecules); ii) polymers that respond to chemical stimuli (pH and ionic strength); iii) polymers that respond to physical stimulus (temperature, ultrasound, light, mechanical stress).…”

“… 68 , 100 , 101 The use of stimulus-sensitive polymers (eg, poloxamers and poly(N-isopropyl acrylamide) in association with mucoadhesive agents, such as chitosan and hydroxypropyl methylcellulose, improves the electrostatic attractions of the formulation with the mucin present in the nasal cavity. 68 , 100 In addition, prolonged drug delivery can be achieved if lipid-based nanosystems are included in in situ hydrogels, which provides a double protection for the drugs as they are encapsulated in the lipid matrix of the nanosystems and within the hydrogel network. 99 , 100 , 104 …”

“… 68 , 100 In addition, prolonged drug delivery can be achieved if lipid-based nanosystems are included in in situ hydrogels, which provides a double protection for the drugs as they are encapsulated in the lipid matrix of the nanosystems and within the hydrogel network. 99 , 100 , 104 …”

Thermosensitive Nasal In Situ Gels of Lipid-Based Nanosystems to Improve the Treatment of Alzheimer’s Disease

“…To circumvent this limitation, the use of mucoadhesive formulations can improve the drugs' residence time in the nasal cavity through the formation of electrostatic interactions between the formulation and mucin [8]. Thermosensitive polymers, such as poloxamers, and mucoadhesive agents, such as chitosan and hydroxypropyl methylcellulose, have been successfully used to prepare thermosensitive in situ nasal gels [9].…”