British team developing gel for sustained release in patients with difficulty swallowing

A team at Britain's University of Huddersfield is developing a gel that enables sustained release of medication in the digestive system, a drug delivery trick usually associated with solid formulations.

The team is using gellan gum, which solidifies in the stomach, but releases the medication within the intestine over a period of several hours. The naturally occurring carbohydrate is a common additive to many food products.

Nonsolid formulations with extended-release profiles are in demand due to the desire for delivery mechanisms for the very young and old populations who have difficulty swallowing.

In a paper published in the International Journal of Pharmaceutics the researchers describe how the drug delivery mechanism prevented release of ibuprofen in simulated gastric fluid.

Release occurred at a pH of 7.4 but was a linear function of the duration of prior exposure and acidity of the fluid. That's because the gel stiffened upon exposure to the acid environment. As a result, when the gel was exposed to acid for 10 minutes, the subsequent release in the alkaline, high-pH environment was faster than when it was exposed for 60 minutes. So, an understanding of the release profile could be harnessed to "tune" the gel to release medication in a predetermined fashion.

In addition, the University of Huddersfield says the team has developed a modified version of the gel that can be used in a standard nasal spray and helps with the retention of drugs in the nose. The formulation consists of gelled microparticles that are suspended in a polymer and behave like a pourable fluid, says the abstract of another paper in the International Journal of Pharmaceutics.

Pharma companies are already experimenting with delivery mechanisms for patients with difficulty swallowing. For example, the capsule of Impax Laboratories' ($IPXL) extended-release Parkinson's med Rytary can be opened so that the beads can be sprinkled on applesauce. In addition, AstraZeneca ($AZN) recently obtained FDA approval to deliver its blood thinner Brilinta as a crushed formulation mixed with water through the nose via a tube.

And a survey by Team Consulting found that a surprising 25% of doctors think patients need to be shown how to swallow tablets at least once.

- read the news from the University of Huddersfield
​- get the oral gel abstract and the nasal spray abstract