Modified geometry three-layered tablet as a platform for class II drugs zero-order release system
Purpose: To optimize a geometrical design of three-layered tablets for controlling the release of indomethacin (Ind) as a BCS class II model.
Methods: The core formulation was optimized to ensure non-disintegrating tablet with a slow release behavior. Three-layered tablets were prepared by a single-step direct compression method by manual feeding of a hydrophobic layer in the bottom followed by Ind core layer and another hydrophobic layer at the top using 6 and 12 mm round compression sets. Four batches were prepared, differing only in either thickness of the drug layer or tablet diameter. A number of factors were studied, including tablet thickness to diameter ratio and drug layer surface area. The rate of Ind released was determined using USP dissolution apparatus I.
Results: The optimum drug layer formulation contained Ind (40%), polyvinylpyrolidone K30 (40 %), and ethyl cellulose (20 %). The t50% (time taken for 50 % drug release) for the four three-layered tablet batches with varying diameter to thickness ratios were in the range of 1.5 to 3.7 h. The diameter to thickness ratios were in good correlation with % Ind release after 4 h (R2 = 0.94). It was found that all batches complied with zero order kinetic model.
Conclusion: The new one-compression phase applied in this study is successful in producing threelayered tablets in a single-step with very good mechanical attributes. The approach of designing a controlled release tablet via control of the surface area of drug release is feasible for non-swelling matrices.
Keywords: Controlled release, Indomethacin, BCS class II drugs, Ethyl cellulose, Release kinetics, Direct compression
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.