In vitro comparison of guar gum-based matrix and compress ion coated colon-specific diclofenac sodium tablets
In vitro comparison of guar gum-based matrix and compress ion coated colon-specific diclofenac sodium tablets
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Date
2015-04-05
Authors
Suleiman, Sundos
Journal Title
Journal ISSN
Volume Title
Publisher
UOFK
Abstract
In order to examine the impact of formulation and processing variables
on colonic drug delivery, 2
3
factorial design was applied in this study to
develop guar gum-based matrix and compression coated colon-specific
tablets.
The influence of guar gum loading level on tablet friability was found to
be more profound with compression coated tablets whereas best matrix
friability was associated with low loading level of MCC regardless of the
drug: guar gum ratio. In both cases, increasing the content of guar gum in
the formulations has resulted in formation of high strength gel. With
matrix formulations, the desired maximum swelling and minimum
erosion tendencies among different formulations tested were shown to be
associated with high loading level of guar gum. However, with
compression coated formulations, the retarding influence (enhancing
erosion effect) of MCC on swelling and erosion in these tablet
formulation is somewhat noticeable. Although it has been found that the
maximum % erosion among these formulations was more sensitive to pH
variation, statistical analysis revealedno significant effect of pH variation
on swelling and/or erosion behaviors of the tested formulations (p≥0.05).
When present as matrixing and/or coating material, content of guar gum
was found to be a determining factorfor the in vitro drug delivery
control. Addition of 4% w/v of rat caecal content to dissolution medium
to mimic colonic fluid was found to enhance the drug release from matrix
and/or compression coated guar gumbased tablets. The result has
indicated that the enhanced release of the drug inpresence of rat caecal
content is due to anaerobic microbialenzymatic action on the swollen
guar gum. Moreover, it has been shown that the enhanced effect of rat
caecal content on drug release fromguar gum based compression coated
formulations is more prominent than with matrix formulations.
In vitro drug release studies showed that guar gum matrix and
compression coated formulations were able to deliver 78% and 89% of
the loaded drug, respectively, inenvironment similar to colonic
conditions by the end of 24hrs with a chance for 22% and 11% of the
loaded dose to be released before reaching the colon from the two types
of formulations, respectively. Consequently, guar gum in form of coating
material is confirmed to be more effective than when present as matrixing
agent for colonic diclofenac sodium delivery, at least under the conditions
of this study
Description
213page
Keywords
guar gum,Time-controlled Systems