Formulation of Sustained-Release Matrix Tablets Using Cross-linked Karaya Gum
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. The optimized formulation was compared with a reference, Dilzem® SR. 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 formulated 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 for tablets prepared with pure K was 99.9 % at the end of 10 h while that tablet made with MK was 68.2 % at the end of 12 h. MK sufficiently controlled the drug release unlike K which exhibited rapid drug release efficiency. SEM images of the tablets before and after dissolution showed some morphological changes on the tablet surface while FTIR and DSC thermogram studies confirmed that there was no chemical interaction between the drug and the polymers in MK formulation. Formulation F6 compared well with Dilzem® SR (reference) (p < 0.05) in terms of release characteristics.
Conclusion: The results of the study demonstrate that modified karaya gum is a potential matrix material for formulating suitable sustained-release matrix tablets of diltiazem.
Keywords: Karaya gum, Diltiazem hydrochloride, Tri-Sodium tri-metaphosphate, Matrix tablets Sustained release.
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.