Hakea Gum:Hakea gum a dried exudate

Hakea Gum:
Hakea gum a dried exudate from the plant Hakea gibbosa
family Proteaceae. Gum exudates from species have been
shown to consist of L-arabinose and D-galactose linked as in
gums that are acidic arabinogalactans (type A). Molar
proportions (%) of sugar constituents Glucuronic acid,
Galactose, Arabinose, Mannose, Xylose is 12:43:32:5:8. The
69 exuded gum is only partly soluble in water .
Hakea gibbosa (Hakea) was investigated as a sustainedrelease
and mucoadhesive component in buccal tablets.
Tablet with drug chlorpheniramine maleate (CPM) with
either sodium bicarbonate or tartaric acid in a 1:1.5 molar
ratio and different amount of Hakea were formulated using a
direct compression technique and were coated with
hydrogenated castor oil (Cutina) on all but one face. The
resulting plasma CPM concentration versus time profiles was
determined following buccal application of the tablets in
rabbits. The force of detachment for the mucoadhesive buccal
tablets increased as the amount of Hakea gum was increased
following application to excised intestinal mucosa. Addition
of sodium bicarbonate or tartaric acid, as well as higher
amounts of CPM, did not affect the mucoadhesive bond
strength. These results demonstrate that the novel, natural
gum, H. gibbosa, may not only be used to sustain the release
70 but can also act as bioadhesive polymer .