Effervescent antacids

Figure 9. Stabilizing effect of methylcellulose on foams generated by a suspension of effervescent antacid granules containing magnesium trisilicate and aluminum hydroxide...

Figure 9 illustrates the stabilizing effect of methylcellulose on the foams generated by a suspension of effervescent antacid granules containing magnesium trisilicate and ammonium hydroxide. Samples 1 and 2 are identical, except for 0.01% of methylcellulose contained in sample 1. The foam in sample 1 (methylcellulose) is stable even after 5 minutes, while the sample without methylcellulose has virtually no foam after 30 seconds. 

Obtain five effervescent antacid tablets. Break each tablet into four equal pieces. One of these pieces will be used for each trial. 

The effect of temperature on reaction rates can be demonstrated with two tablets of effervescent antacid, two cups, and tap water. Into one cup, place a half cup (120 milliliters) of cool tap water from the faucet. In the other cup, place an equal amount of hot tap water from the faucet. Drop one tablet into each cup at the same time. The fizzing action is clearly more vigorous in the hot water than in the cool water. In this case, the higher temperature helps in two ways. It forces more bubbles out of solution (which is the same reason you re cautious about opening a warm can of soda), and it increases the reaction rate because molecules at a higher temperature move around faster, find each other more often, and hit each other harder when they do. This effect and other principles concerning chemical kinetics is the subject of the following discussion. 

Among effervescent antacid preparations, Alka-Seltzer, an effervescent antacid analgesic product, has been available since the 1930s. Pure effervescent antacid products are marketed in many countries. 

Sodium bicarbonate is a gastric antacid that may cause systemic alkalosis on overdose and may contribute to edema owing to sodium retention. It is useful for systemic acidosis because both deficient ions are present in the same molecule, and it can be used topically as a moist paste or in solution as an antipmritic. Sodium bicarbonate also is an ingredient of many effervescent mixtures, alkaline solutions, etc. One gram of NaHCO neutralizes 115 mL 0.1 NHCl. 

Potassium bicarbonate is used in baking powder and effervescent salts. In medicine, the salt is a gastric antacid and an electrolyte replenisher. It also is dry powder in fire extinguishers. 

Antacids Alka-Seltzer Original Effervescent Tablet (568) Alka-Seltzer Extra Strength Effervescent Tablet (588) Alka-Seltzer Gold (309) Alka-Seltzer Heartburn Relief (575) Brioschi (500/6 g dose) Bromo-Seltzer Granules (959/pre-measured packet) Citrocarbonate Effervescent Granules (701/tsp)... 

Earnest D, Robinson M, Rodriguez-Stanley S, Ciociola AA, Jaffe P, Silver MT, Kleoudis CS, Murdock RH. Managing heartburn at the base of the GERD iceberg effervescent ranitidine 150 mg b.d. provides faster and better heartburn relief than antacids. Aliment Pharmacol Ther 2000 14(7) 911-18. 

Sodium bicarbonate is metabolized to the sodium cation, which is eliminated from the body by renal excretion, and the bicarbonate anion, which becomes part of the body s bicarbonate store. Any carbon dioxide formed is eliminated via the lungs. Administration of excessive amounts of sodium bicarbonate may thus disturb the body s electrolyte balance, leading to metabolic alkalosis or possibly sodium overload with potentially serious consequences. The amount of sodium present in antacids and effervescent formulations has been sufficient to exacerbate chronic heart failure, especially in elderly patients. ... 

Sodium bicarbonate is also used in a number of pharmaceutical applications. For example, it is a common ingredient in antacids, products designed to relieve heartburn, acid indigestion, sour stomach, and other discomforts caused by overeating or improper foods. Some pharmaceuticals, such as Alka-Seltzer , contain a combination of citric acid and sodium bicarbonate. The citric acid helps the sodium bicarbonate dissolve more quickly and produces more effervescence when the tablet is dissolved in water. 

Bicarbonate of soda, Na 0, 2 COj + aq, forms a white powder, which is alkaline, and is much used in medicine as a mild antacid, and as one of the ingredients in effervescing or Seidlitz powders. 

HMIS Health 1, Flammability 0, Reactivity 0 Storage Moisture-sensitive store in cool, dry place keep containers sealed Uses Mfg. of effervescent salts and beverages, artificial mineral water prevention of timber mold cleaning preps. blast cleaning lab reagent antacid mouthwash OTC drug active ... 

A term used to describe a liquid that is bubbling because it is giving off bubbles of gas. A common effervescent liquid is a solution of baking soda, which releases carbon dioxide. (The latter solution is used mainly as an antacid or a leavening agent in baking.)... 

---