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Research Article
Formulation of
Sustained-Release Matrix Tablets Using Cross-linked
Karaya gum
Mahesh M Reddy, Jagadeeswara D Reddy, Afrasim Moin*
and HG Shivakumar
JSS College of Pharmacy,
JSS University, Mysore, Karnataka-570015, India
For correspondence:
Email:
afrasimmoin@yahoo.co.in Tel: +91
9886652844
Received: 16 February
2011 Revised
accepted: 3 December 2011
Tropical
Journal of Pharmaceutical Research, February 2012;
11(1): 28-35
http://dx.doi.org/10.4314/tjpr.v11i1.4
Abstract
Purpose:
To develop sustained release matrix tablets of diltiazem
hydrochloride (DTZ) using modified karaya gum (MK).
Methods:
MK was prepared by cross-linking karaya gum with
tri-sodium tri-metaphosphate (STMP) which was used as a
cross-linker. Matrix tablets of DTZ were prepared using
varying ratios of unmodified karaya gum (K) and MK by
direct compression. The matrix tablets were evaluated
for pharmacotechnical properties and in vitro release,
including release kinetics. The optimized formulation
was compared with Dilzem SR which served as reference.
MK and the formulations were also characterized by
scanning electron microscopy (SEM), Fourier transform
infra-red spectroscopy (FTIR) and differential scanning
calorimetry (DSC).
Results:
Tablets with MK showed higher mean dissolution time
(MDT) and lower dissolution efficiency than those
prepared with karaya gum. Drug release was by water
uptake, diffusion and erosion mechanisms. Drug release
from tablets formulated with unmodified K at the end of
10 h was 99.9 %, and while for MK tablets, it was 68.2 %
at the end of 12h. MK sufficiently controlled drug
release unlike K which exhibited poor sustained drug
release. Formulation F6 compared well with the
reference, Dilzem SR (p <0.05), in terms of release
characteristics. Cumulative drug release at the end of
12 h for both test and reference formulations was
approx. 85 %. SEM images of the tablets before and after
dissolution showed some morphological differences on
their tablet surfaces while FTIR and DSC thermogram
studies confirmed that there was no chemical interaction
between the drug and the polymers in MK formulation.
Conclusion:
The results of the study demonstrate that modified
karaya gum has good potentials for formulating suitable
sustained-release matrix tablets of diltiazem.
Keywords :
Karaya gum, Diltiazem hydrochloride,
Tri-Sodium Tri-metaphosphate,
Crosslinking, Matrix tablets, Sustained release. |
