Development of Acid-Neutralization and in Vitro Dissolution to Evaluate the Overall Quality of Compound Aluminum Hydroxide Tablets

Background: Compound aluminum hydroxide tablets (CAHTs) are widely used in the Chinese domestic market, and strict quality control is required to ensure their clinical efficacy. Purpose: In this study, we established a comprehensive strategy of acid-neutralization, in vitro dissolution and an assay of magnesium trisilicate to evaluate the overall quality and monitor the consistency of CAHTs. Methods: The acid-neutralization profiles of 38 batches of CAHTs were generated using the dissolution and release method III (the cup method, the Chinese pharmacopeia) combined with potentiometric titration. To directly reflect the disintegration and release process of the preparation, we optimized the sample pretreatment method by omitting the grinding step to determine the profiles of complete tablets. In addition, in vitro dissolution was conducted in the hydrochloric acid medium at pH 1.0 by using the assay of magnesium trisilicate through a validated approach of flame atomic absorption spectrophotometry (FAAS) to evaluate the similarity of the dissolution profiles. Results: Acid-neutralization tests showed that the quality of the samples from manufacturers B and F was poor. In vitro dissolution experiments showed that the samples from manufacturer A had the highest similarity with the reference preparation, which indicated their good quality consistency. Besides, the optimized acid-neutralization method had the advantage of simple operation and enabled direct characterization of pharmacodynamics in the quality consistency evaluation of antacids. Conclusion: A successful synthetic evaluation strategy was established to assess the overall quality of CAHTs, which demonstrated that the improvement in the quality of this formulation is imperative.

Enhanced solubilization of insoluble silicate from quartz and zeolite minerals by selected Aspergillus and Trichoderma species

Silicon (Si) is a major component of sand, silt and clay particles of soils. Available silica as silicic acid (H4SiO4) present in soil solution is considerably low, only in the range of 3.5–40.0 mg Si L-1. To improve plant-available Si in the soil, silicate-solubilizing fungi (SSF) are potentially important in solubilizing insoluble forms of silicate (SiO2). The objectives of this study were to determine silicate solubilizing capacity and organic acid produced by seven SSF isolates on Bunt and Rovira media by using 0.25% (w/v) magnesium trisilicate (Mg2O8Si3), quartz, and zeolite as a silica source. Determination of SSF isolates potential in Si solubilization was carried out in a completely randomized design with three silica sources and three replicates. The results indicated that all SSF were capable of producing acetic, citrate, and oxalic acids and enhancing the solubilization of insoluble silicates. Trichoderma polysporum and Aspergillus niger BCCF194 were the best isolates of SSF. Furthermore, there was significantly (p<0.05) positive correlation between solubilizing silicate capacity by using quartz or zeolite as a silica source on Bunt and Rovira media with incubation time (R2 = 0.79-0.99) and citric acid production (R2= 0.97-0.99) from T. polysporum and A. niger BCCF194

Magnesium Trisilicate Coated Fe3O4 Nanoparticles as Prompt and Efficient Lactic Acid Removers Potential for Exercise-Induce Fatigue Prevention

Exercise-induced fatigue is accumulated when lactic acid cannot be timely eliminated after intensive exercise, resulting in sport injuries. Traditional lactic acid removal methods are limited in timeliness, metabolic burden, and potential toxicity. To solve the thorny problems, in this study, nanomedicine was introduced for lactic acid removal. Magnesium trisilicate was coated on the surface of magnetic nanoparticles. These nanoparticles exhibited a prompt and efficient lactic acid adsorbing behavior. Moreover, they have favorable magnetic properties and good biocompatibility. The results showed that the prepared nanoparticles hold great potential in the removal of lactic acid for preventing exercise-induced fatigue.