Nasal gel alternative to insulin injection


An international team of scientists has developed a novel insulin delivery system for nasal administration. The study aims to provide an alternative to regular injections through the delivery of insulin via the nasal membrane in the form of a hydrogel. This route offers a relatively high bioavailability, avoidance of the first-pass effect (in which a drug’s concentration is reduced before it reaches the systemic circulation) and painless administration.

Considerable research effort has been dedicated to developing alternative non-invasive insulin delivery systems, including oral and transcutaneous administration. The major limitations of nasal delivery are the rapid mucociliary clearance of a drug to the nasopharynx, resulting in a short time span for its absorption, and the low permeability of the nasal membrane to peptides such as insulin because of tight junctions between epithelial cells.

Hamde Nazar at the University of Sunderland, UK, who led the team while she was at the University of Portsmouth, explains that ‘characteristics of mucoadhesion and the ability to facilitate transport of insulin through the transient opening of tight junctions were achieved through the employment of trimethylated chitosan’. In combination with additives glycerophosphate and polyethylene glycol, their formulation transitions to a gel state upon exposure to the warm physiological temperature within the nasal cavity, providing a barrier to the continuous clearance mechanism of the cilia and prolonging the residence at mucosal surfaces.

Picture depicting the delivery of insulin via the nose

The formulation affects the controlled delivery of insulin, demonstrated by a reduction in blood glucose over 24 hours. © Shutterstock

Vicky Kett, a member of the drug delivery research group at Queen’s University Belfast, Northern Ireland, remarks that the in vivo experiments that the team carried out in rats demonstrate ‘good insulin release and clear effects on glucose levels. The use of a thermogelling system offers clear advantages over solutions that are rapidly cleared to the nasopharynx.’ She also notes that ‘many insulin nasal formulations, such as Nasulin developed by CPEX Pharmaceuticals, US, showed early promise but failed in clinical testing, so there is some way to go before this formulation could be developed into a licensed product.’

Nazar’s team plans to extend their work by developing a smart hydrogel system able to respond to glucose levels and allow a proportional release of insulin, eliminating the need for regular blood monitoring and dosage adjustment.

 


Related Content

Delivering insulin in a skin cream

23 July 2012 Research

news image

Injections and tablets could one day be a thing of the past

Insulin

19 November 2014 Podcast | Compounds

news image

A protein with an impressive roster of 'firsts': Anna Lewcock introduces insulin

Most Read

Graphene sandwich turns water square

27 March 2015 Research

news image

Water trapped between graphene sheets transformed into new type of ice

Fractal first as molecules form Sierpinski triangles

30 March 2015 Research

news image

Scientists have produced a repeating triangular pattern through molecular self-assembly

Most Commented

Sewage offers attractive source of precious metals

27 March 2015 Research

news image

US Geological Survey team finds valuable metals in treated sewage and is working on the difficult problem of extraction

Fractal first as molecules form Sierpinski triangles

30 March 2015 Research

news image

Scientists have produced a repeating triangular pattern through molecular self-assembly