Comparison of Flow-Through
Cell and Paddle Methods for Testing Vaginal Tablets
Containing a Poorly Water-Soluble Drug
Emilia Szymanska and
Katarzyna Winnicka*
Department of Pharmaceutical
Technology, Faculty of Pharmacy, Medical University of
Bialystok, Mickiewicza 2c, 15-222 Bialystok, Poland
*For correspondence: E-mail:
kwin@umb.edu.pl
Tel: +48-857485616
Received: 31 January
2012
Revised accepted:
26 November 2012
Tropical
Journal of Pharmaceutical Research, February 2013;
12(1):
39-44
http://dx.doi.org/10.4314/tjpr.v12i1.7
Abstract
Purpose: To evaluate the usefulness
of the flow-through cell apparatus for testing
commercial vaginal tablets containing poorly
water-soluble clotrimazole.
Methods: The effect of experimental
conditions (type of dissolution medium, flow rate and
positioning of the tablet) on the dissolution profile of
clotrimazole were examined and optimal parameters for
conducting the experiments were determined.
The
amount of drug released was analyzed by high performance
chromatography (HPLC) at 210 nm.
The usefulness of the
flow-through cell apparatus was compared to FDA
recommended paddle apparatus.
Results: Using acetate buffer pH 5.2
containing 1 % SDS, both methods gave different
dissolution profiles. The paddle apparatus tended to
give faster rate of dissolution (approx. 88.5 % during
the first 20 min of the experiment), which was probably
caused by higher agitation and greater surface area of
the drug-dissolution medium in a vessel.
In
the flow-through cell method, total drug release was
definitely slower and was observed after 2 to 5 h; at a
flow rate of 16 ml/min, more than 80 % of the drug
dissolved after 30 min of the test. It was noticed that
raising the flow rate of the dissolution medium caused
significantly higher drug release.
Conclusion: The results demonstrate
that the flow-through cell method is reproducible and
can be successfully used for evaluating in vitro
dissolution of clotrimazole from non-modified release
tablets. The slower rate of dissolution obtained in the
flow-through cell method would help to distinguish
between different formulations.
Keywords: Dissolution test,
Flow-through cell method, Paddle method, Clotrimazole.
