Effect of Exchanged MgAl-Hydrotalcite with Carbonate on Increases of Acid Neutralizing Capacity: A Good Candidate as an Antacid

Abstract

Background: In this study, we determined the acid-neutralizing capacity (ANC) of Mg/Al-Hydrotalcite-like compounds. The MgAl-hydrotalcites were synthesized by the co-precipitation method at room temperature using Mg/Al molar ratios 2:3. The synthesized bioactive nanomaterials were characterized by various physicochemical techniques such as TG/dTG, XRD, FT-IR spectroscopy, BET/BHJ, and SEM/EDX. The antacid activity assay was done by converting both synthesized samples into liquids, 1 g of which was added to 50 ml of deionized water at 37°C under vigorous agitation. The acid-neutralizing capacity (ANC) was evaluated with 0.1N HCl. The pH was constantly measured using a pH meter and values were recorded every minute up to 35 min. In order to improve the neutralizing power of the samples, we performed an exchange of chlorides by carbonates on the MgAl-HT3 synthesized. The exchanged Mg/Al-Hydrotalcite (MgAl- HTE) showed high acid neutralization capacity (up to 13.5 mEq/g). Objective: This study aimed to synthesize MgAl-hydrotalcite-like compounds and evaluate their acid-neutralizing capacity. In order to can be good candidates for pharmaceutical applications as antacid drugs. Methods: Following methods are used in this study: - Preparation of MgAl-hydrotalcite-like compounds was done by coprecipitation methods. - Characterization of samples was done by physico-chemical techniques such as TG/dTG, XRD, FT-IR spectroscopy, BET/BHJ and SEM/EDX. - Evaluation of acid-neutralizing capacity was done by titration procedure (Dose-titration). Results: This protocol describes the preparation of MgAl-hydrotalcite-like compounds using the classical coprecipitation method. The synthesized samples were characterized by various physicochemical techniques such as TG/dTG, XRD, FT-IR spectroscopy, BET/BHJ, and SEM/EDX. The as-synthetized samples were used for the evaluation of their acid-neutralizing capacity (ANC). Further, an exchanged of MgAl-Hydrotalcite with carbonate was done for the purpose to increase the acid-neutralizing capacity. Conclusion: In summary, this study describes a simple synthesis of MgAl-Hydrotalcites compounds by a co-precipitation method at constant pH around 10, with a ratio Mg/Al = 3:2 (referred to as MgAl-HT3 and MgAl-HT2). An exchange of the chlorides (not eliminated by washing) by the carbonates was carried out on hydrotalcite with a ratio Mg/Al = 3, and the solid obtained was named MgAl-HT3E. The materials MgAl-HT2, MgAl-HT3, and MgAl-TH3E were used to evaluate antacid activity. To this end, a study was conducted to determine the acid-neutralizing capacity (ANC). As result, the MgAl-HT3E was able to increase acid-neutralizing capacity and maintain an ideal pH. These results could be interesting to prepare novel antacid drugs (due to the low cost of synthesized materials) essentially the hydrotalcite of mg/Al ratio equal to 3 because of its relatively slow kinetics of releasing basic species and therefore of its beneficial action as an antacid.