Formulation and Characterization of Plumbagin Matrix Tablets Using a Grafted Polysaccharide Carrier for Direct Compressibility and pH-Sensitive Drug Release

Research Article

Abstract

In this study, directly compressible plumbagin (PLB) matrix tablets were prepared using a modified poly(acrylamide)-grafted-carboxymethyl xanthan gum (CMXG-g-PAAm) polymer. Chemical compatibility between the naphthoquinone bioactive and the polymeric carrier was established via Fourier Transform Infrared Spectroscopy (FTIR), showing no deleterious interactions. Evaluation of the powder blend for pre-compression attributes indicated excellent flowability and packing properties, facilitating efficient processing via the direct compression technique. The resulting tablets complied with all pharmacopeial standards regarding weight uniformity, mechanical strength, and drug loading. Stability studies conducted over a six-month duration under accelerated conditions confirmed the robust nature of the dosage form. Dissolution studies revealed a significant pH-dependent modulation of drug release. In an acidic environment, the formulation exhibited a release profile governed primarily by diffusion coupled with moderate matrix participation. On the other hand, at intestinal pH levels, the system transitioned to near zero-order kinetics. This shift is attributed to the substantial swelling and erosion behavior of the CMXG-g-PAAm matrix in neutral-to-alkaline conditions. These results indicate that the developed matrix system provides an effective platform for the sustained delivery of plumbagin, potentially improving therapeutic outcomes through prolonged residence and controlled absorption within the intestinal tract