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Original
Research Article
Estimation of the
release profiles of multi-unit dose tablets of
theophylline from the release profiles of their
components
MU Uhumwangho* and RS
Okor
Department of Pharmaceutics and
Pharmaceutics Technology, University of Benin, Benin
City, Nigeria
Correspondence:
E-mail:
mike2003u@yahoo.com
or
uhumwangho@uniben.edu Tel:
+234-8052057767
Tropical
Journal of Pharmaceutical Research, June
2008; 7(2):
981-986
Abstract
Purpose:
The objective of this
study is to investigate whether the drug release profile
of a multi-unit dose form consisting of fast and slow
release components can be predicted from the release
profiles of their components by simple summation.
Method:
The fast release component consisted of
conventional granules of theophylline made by wet
massing the drug powder with starch mucilage (20%w/v).
The slow release component consisted of matrix granules
of the drug made by triturating the drug powder with
melted carnuba wax (i.e. melt granulation). Each type of
granules was compressed to tablets of weight 100, 150 or
200mg. To form the multi-unit dosage tablets of drug
content 300mg each, the conventional and matrix granules
were mixed in the ratio 1:2, 1:1 and 2:1, and
compressed. The tablets were subjected to dissolution
test and from the experimental release curve the prompt
release (mp) in the first 1h, the maximum
release (m∞) and the time to attain it (t∞)
were obtained.
Result:
For a given composition of the multi-unit
dose tablets, the theoretical release curve was obtained
by summation of the release from each component at the
different time intervals. The mp values of
the theoretically estimated release curves were
generally higher, while their t∞ values were
generally shorter than the corresponding values for the
experimental curves.
Conclusion:
The indication is that drug
release from the multi-unit dose tablets was more
retarded than could be theoretically estimated.
Apparently, the two components interfere with each
other’s release.
Keywords:
single-unit and
multi-unit dose forms, release profiles, theophylline |
