Xanthan and Locust Bean Gum (from Ceratonia siliqua) Matrix Tablets for Oral Controlled Delivery of Metoprolol Tartrate

Purpose: Development of a controlled delivery of metoprolol tartrate using the synergistic activity of locust bean gum (LBG) and Xanthan gum (X). Method: Metoprolol tartrate granules were prepared using different ratios of drug: gum (X, LBG and mixture of XLBG). To increase the flowability and compressibility of the granules, and to prevent its adhesion to punch and die, magnesium stearate and talc were added to the granules in 1:2 ratio respectively before punching. The tablets were analysed for their hardness, friability, % assay and in vitro release study was carried out. Results: The release of drug from a gelatinous swollen mass, which controls the diffusion of drug molecules through the polymeric material into aqueous medium. The XLBG matrices show precise controlled release than the X and LBG matrices because of burst effect and fast release in case of X and LBG alone respectively. FTIR and DSC thermogram studies confirmed that there was no chemical interaction between drug and polymers in XLBG formulation. First pass effect of metoprolol tartrate can be avoided by this formulation. However, according to the similarity factor (f2) XLBG3 was most similar to Meto-ER as the reference standard. Conclusion: The XLBG matrices leads to more precise result than X and LBG matrices due the utilization of synergistic interaction between two biopolymers and lower average size of this allowing a uniformity with the tablet hydration in dissolution media.