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32D April 2020 Tablets & Capsules tribasic in water will cause a reaction and temperature increase. An exothermic reaction will occur if an unre- acted acid and excess hydroxide/oxides react post blend- ing upon rehydration. Additionally, if such a blend is exposed to water during wet granulation or if the product is added to a consumer's drink, a reaction might occur at an inopportune time and damage the product's integrity. Besides creating an unstable end product, formulations that contain blended mineral ingredients may also have a misstated ingredient label. For example, a magnesium citrate product may list the magnesium content at 20 per- cent, but this is not possible based upon the stoichiome- try of a fully reacted salt. Per the USP monograph, mag- nesium citrate tribasic can only offer 11.2 to 12.0 percent magnesium on the "As-Is" basis in the hydrated form. Table 1 shows the fully reacted mineral content of several mineral supplement products. Products that claim higher magnesium content levels than those listed are likely blends. Appropriate labeling should list the ingredi- ents comprising a "blend" such as magnesium citrate and magnesium oxide, so that the finished product complies with the FDA ingredient declaration mandates. Higher mineral content is a marker for an adulterated product, typically as an oxide, hydroxide, or carbonate. Stability and performance issues increase as the level of adulterant increases. Furthermore, product labeling com- pliance will be an issue if the added adulterant does not appear on the ingredients list. By using fully reacted min- eral salts, dietary supplement manufacturers can ensure stability, consistent performance, and good bioavailabil- ity and avoid product labeling compliance issues. Reference 1. www.grandviewresearch.com/industry- analysis/ mineral-supplements-market Jost Chemical is a manufacturer of high purity specialty chemicals (314 428 4300, www.jostchemical.com). The company supplies fully reacted, pure mineral salts that meet USP/EP/FCC monographs. In October 1994, the US Congress passed the Dietary Supplement Health and Education Act (DSHEA), which called for the establishment of current Good Manufactur- ing Practices (cGMPs) for dietary supplements. However, many widely used mineral salts still lack published mono- graphs, and instances of non-compliance with established dietary supplement monographs reinforce the need for good chemistry and accurate content disclosure. This can leave supplement manufacturers wondering whether the ingredients they buy are of good quality and safe for their intended use and how those ingredients are affecting the quality of their finished products. Manufacturers can safeguard against these and other concerns by using fully reacted mineral salts. Fully reacted salts are manufactured by a reaction of an acid and a base in an aqueous solution and the precipitation of a salt compound. A dry blend of an acid and a base often results in a partially reacted product. The acid and base might mix completely, but the reaction may not proceed to completion, causing performance and stability issues if the partially reacted mineral salt is used in a formulation. It takes skilled chemists, chemical engineers, and production operators to drive reactions to completion, resulting in quality mineral salts. Manufacturers can dif- ferentiate between a fully reacted mineral salt and a blend of reactants using infrared spectroscopy, nuclear mag- netic resonance spectroscopy, thermal gravimetric analy- sis, or numerous other analytical techniques. To illustrate the problems blended and partially reacted salts can cause mineral supplement product man- ufacturers, let's consider magnesium. The magnesium sup- plement market is forecast to grow at a compound annual rate of 7.1 percent through 2025 [1]. While it's important for everyone to achieve the recommended daily intake of magnesium, supplementation can be especially bene- ficial for heart patients and diabetics. Magnesium helps regulate heart rate and blood pressure, reducing the risk of several cardiovascular diseases, and also helps control blood glucose levels. Using partially reacted magnesium can reduce a sup- plement's quality and effectiveness. For example, most fully reacted salts have a fairly neutral pH, while blended products might exhibit an acidic or alkaline pH. A par- tially reacted blend can be unstable because the alkaline minerals will continue to slowly react with any acidic ingredients in the formula. This instability can cause the blend to harden or the tablets to disintegrate over time. A blended product might be low or high in pH because of an imbalance in the acid-base stoichiometry. The pH imbalance can lead to problems with the product's integ- rity. Structure and content uniformity can suffer if a prod- uct contains a mineral blend with a partially reacted salt. In compounding operations, blends can separate based on differing physical characteristics. Depending on the mineral salt, the addition of an acid to a sample can demonstrate the presence of unreacted mineral carbonate, as effervescence of the acid will occur. Putting a partially reacted hydrated magnesium citrate Mineral (As-Is) Percentage Calcium citrate tetrahydrate 20.5-21.2 CCM 20.0-26.0 Calcium malate 20.0-23.5 Ferrous gluconate USP 10.9-11.9, EP 11.8-12.5 Magnesium citrate tribasic hydrate 11.2-12.0 Magnesium aspartate dibasic 14.2-15.7 Magnesium ascorbate 6.1-6.6 Magnesium glycinate NLT 10 Magnesium malate trihydrate 11.3-11.8 Manganese citrate 22.0-23.9 Manganese gluconate 11.0-11.9 Zinc citrate 31.3-32.1 Zinc gluconate 12.3-14.6 Table 1 Fully reacted mineral content of mineral supplement products