Comparison of Flow-Through Cell and Paddle Methods for Testing Vaginal Tablets Containing a Poorly Water-Soluble Drug
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
Submission of a manuscript to this journal is a representation that the manuscript has not been published previously and is not under consideration for publication elsewhere.
All authors named in each manuscript would be required to sign a form (to be supplied by the Editor) so that they may retain their copyright in the article but to assign to us (the Publishers) and its licensees in perpetuity, in all forms, formats and media (whether known or created in the future) to (i) publish, reproduce, distribute, display and store the contribution, (ii) translate the contribution into other languages, create adaptations, reprints, include within collections and create summaries, extracts and/or abstracts of the contribution, (iii) create any other derivative works(s) based on the contribution, (iv) to exploit all subsidiary rights in the contribution, (v) the inclusion of electronic links from the contribution to third party material where-ever it may be located, and (vi) license any thrid party to do any or all of the above.