Magnesium compounds antacids

Some magnesium compounds are important over-the-counter medicines. For example, milk of magnesia is a suspension of magnesium hydroxide (Mg[OH]2) in water. This creamy liquid suspension is used as an antacid to neutralize excess acid in the stomach. Another magnesium compound remedy is Epsom salts, which are used to treat certain skin rashes. Discovered in Epsom, England, in 1618, these are crystals of magnesium sulfate evaporated from water. 

Carbonic acid, magnesium salt (1 1), mixture with magnesium hydroxide (Mg(OH)2), hydrate CCRIS 7884 Magnesium carbonate basic Magnesium carbonate hydroxide Marinco C. A basic magnesium carbonate of variable composition. Used in fireprooSnp, as an antacid and laxative and in manufacture of magnesium compounds. 

Magnesium-containing compounds are often common everyday medicines. What makes milk of magnesia an effective antacid ... 

Inorganic compounds such as aluminium hydroxide, sodium bicarbonate, and magnesium and calcium carbonates are commonly used as antacids. There is much scope for the redesign of these agents to achieve fine control of local pH values in the gastrointestinal tract via control of the rate of release of the active bases (e.g., from insoluble compounds). 

All basic magnesium phosphates find apphcations in plastics as stabilizers. Other than this, monobasic salt is used in fireproofing wood. The dibasic phosphate is a food additive and also a laxative. The tribasic phosphate is an antacid and a nutritional food supplement. The compound also is an adsorbent and a pohshing agent in dental work. 

Acids and bases are among the most familiar of all chemical compounds. Acetic acid in vinegar, citric acid in lemons and other citrus fruits, magnesium hydroxide (milk of magnesia) in commercial antacids, and ammonia in household cleaning products are among the acids and bases that we encounter every day. Hydrochloric acid is... 

Because acid-pepsin disease rarely occurs in the absence of gastric acid and pepsin, antacids are highly effective in its overall management. Antacids consist of a mixture of magnesium, aluminum, and calcium compounds. Their efficacy is based on their inherent ability to react with and neutralize gastric acid. Sodium bicarbonate, which may leave the stomach rapidly, can cause alkalosis and sodium retention. Calcium salts may produce hypercalcemia, which can be detrimental in patients with impaired renal function. Aluminum salts may decrease the absorption of tetracyclines and anticholinergic drugs. 

Peterson CL, Perry DL, Masood H, et al. Characterization of antacid compounds containing both aluminum and magnesium. II Codried powders. Pharm Res 1993 10(7) 1005—1007. 

Compounds used as antacids are sodium bicarbonate potassium bicarbonate calcium carbonate aluminium hydroxide magnesium salts... 

Because strong bases are completely ionized, the molarity of hydroxide ion in sodium and potassium hydroxide solutions, the monohydroxy bases, is the same as the molarity of the base itself. The OH molarity in 0.10 M NaOH is 0.10 M. In the case of Ca(OH)2, a dihydroxy base, the OH molarity is exactly two times the molarity of Ca(OH)2. Not all hydroxide compounds function well as bases because of their low solubility in water. Aluminum hydroxide, Al(OH)3, and magnesium hydroxide, Mg(OH)2 can both neutralize acids (they are used in several antacids) but neither is very soluble and cannot used to prepare solutions. 

Other effective antacids, which are used separately or with aluminum hydroxide or magnesium trisilicate, include dihydroxyaluminum amino-acetate, hydrated magnesium aluminate, dihydroxyaluminum sodium carbonate, and others. Each of these compounds has been demonstrated to be as useful as antacids but has not been so popular as calcium carbonate or aluminum hydroxide. 

The alkaline earth hydroxides are not very soluble and are used only when the solubility factor is not important. In fact, the low solubility of these bases can sometimes be an advantage. For example, many antacids are suspensions of metal hydroxides, such as aluminum hydroxide and magnesium hydroxide. The low solubility of these compounds prevents a large hydroxide ion concentration that would harm the tissues of the mouth, esophagus, and stomach. Yet these suspensions furnish plenty of hydroxide ion to react with the stomach acid, since the salts dissolve as this reaction proceeds. 

The serum levels of many of the quinolone antibacterials can be reduced by aluminium and magnesium antacids. Calcium compounds interact to a lesser extent, and bismuth compounds onfy minimal. Separating administration by 2 to 6 hours where significant interactions occur reduces admixture in the gut and can minimise the effects. 

Didanosine is extremely acid labile at pH values below 3, so one ofthe formulations contains buffering agents (dihydroxyaluminium sodium carbonate and magnesium hydroxide) to keep the pH as high as possible to minimise the acid-induced hydrolysis. Ciprofloxacin forms insoluble non-absorbable chelates with these metallic ions in the buffer so that its bioavailability is markedly reduced. See also Quinolones + Antacids or Calcium compounds , p.328. 

---