Research Highlights

Gum polymer delivers curcumin

doi:10.1038/nindia.2012.50 Published online 11 April 2012

Researchers have designed a new kind of mucoadhesive tablet that can deliver curcumin through buccal mucosa, the lining of the cheeks and lips inside the mouth. The tablet is made from the natural mucoadhesive polymer cashew nut tree gum, which increases the bioavailability of curcumin and other drug molecules bypassing the degrading fluids present in the gastrointestinal tract.

Curcumin has antioxidant, anti-inflammatory and anticarcinogenic properties, but unfortunately suffers from poor absorption through the gastrointestinal tract. In contrast, the immobile, smooth muscle and blood vessels-rich architecture of buccal mucosa is an excellent alternative route for delivering large unstable proteins, including drug molecules such as curcumin.

To find a biodegradable and non-toxic delivery material for curcumin, the researchers purified cashew nut tree gum with alcohol and water and then used the water-soluble portion to prepare two types of buccoadhesive tablets — placebo and curcumin tablets. The placebo tablets contained only varying concentrations of the gum, whereas the curcumin tablets contained granules of curcumin with varying concentrations of the gum.

Placebo tablets were placed behind the upper lips of nine healthy individuals for 14 days to explore issues of discomfort, taste, dryness, irritation, redness and disintegration. Two of the individuals felt slight irritation. In addition, the researchers investigated the hardness, mucoadhesive strength and swelling of the tablets in chemical solutions that simulate physiological conditions and goat intestinal membrane that mimics buccal mucosa.

The gum exhibited good water-absorbing and swelling properties. This may help form hydrated three-dimensional networks between gum polymer and buccal mucous layer, from which drug release might follow by diffusion.

"The cashew nut tree gum showed faster drug release than hydroxypropyl methyl cellulose, a standard mucoadhesive polymer, making it a potent biopolymer for buccal drug delivery," says lead researcher K. Gowthamarajan.


References

  1. Gowthamarajan, K. et al. Development of buccal tablets for curcumin using Anacardium occidentale gum. Carbohydr. Polymer. 88, 1177-1183 (2012)  | Article |