TANNINS:
Bhara Gum:
Gum Bhara is a yellowish natural gum of plant Terminalia
bellerica roxb. belonging to family Combretaceae. Bahera
gum, extracted from the bark of Terminalia bellerica, is a
92 waste material . Main chemical constitutents are tannins
which mainly include ß- sitosterol, gallic acid, ellagic acid,
93 ethyl gallate, galloyl glucose and chebulaginic acid .
It has been mainly used as a demulcent and purgative. It is
also used as an emulgent in cosmetic industries. Wide
applications of bhara gum indicate their hydrophilic nature,
94 and compatibility with the physiologic environment .
A new sustained release microencapsulated drug delivery
95 system employing bhara gum has been proposed . The
microcapsules were formulated by ionic gelation technique
using famotidine as the model drug. The effect of different
drug: bhara gum ratio on in vitro drug release profile was
examined and compared with guar gum. Remaining all
parameters was constant. Microcapsules employing bhara
gum exhibited slow release of famotidine over 10 hr. Fickian
release was observed from most of the formulations with
bhara gum. It was concluded that this gum possesses
substantial release controlling properties that could be used
for sustained drug delivery. biodegradable and with few exceptions, also biocompatible.
Majority of investigations on natural polymers in drug
delivery systems center around polysaccharides. Natural
gums can also be modified to have tailor-made products for
drug delivery systems and thus can compete with the
synthetic controlled release excipients available in the
market. Though the use of traditional gums has continued,
newer gums have been used, some of them with exceptional
qualities. Many other new gums viz. sesbenia gum, tara gum,
etc. can be explored for their sustained release properties.
These have found application not only in sustaining the
release of the drugs but are also proving useful for
development of gastro retentive dosage form, bioadhesive
system, microcapsules etc.