| The objective of this study was to assess an in vitro dissolution of Diclofenac sodium from single-unit matrix tablets for colon drug delivery. The matrix tablets were composed of natural polymers (Pectin and Xanthan gum). The ratio of Pectin and Xanthan gum was varied into 6 different formulas. The study was divided into two different parts. The first part was aimed to determine in vitro release of Diclofenac sodium and the second part was to study an accelerated stability test. Moreover the matrix tablets after being coated with Eudragit-S 100 were tested for primary quality control as listed in USP XXX/ NF XXV standard (e.g., weight variation, percent friability, hardness, thickness, and content uniformity).
The results demonstrated that all 6 formula passed the requirements of USP XXX/ NF XXV. The matrix tablets were coated using Eudragit-S 100 since its property of dissolving in pH > 7. An in vitro dissolution test was carried in acid condition (pH 1.2), small intestine condition (pH 6.8) and large intestine condition (pH 7.4) and completed in 24 hours. Pectin showed a faster released than those of Xanthan gum. While Xanthan gum performed a slow release with increasing concentration. The optimal ratio of Pectin= Xanthan gum, which displayed a fast and continue release to 24th hour, was Pectin 60 mg= Xanthan gum 15 mg. The accelerated stability study showed a change of release significant profile in the 3 months period of study. It could be concluded that the formula with optimize ratio of Pectin and Xanthan gum (60 mg= 15 mg) should be studied further in human. |