Sodium bicarbonate Aspirin

Mylanta Liquid—simethicone, sorbitol Nephrox Liquid—aluminum hydroxide, mineral oil Original Alka-Seltzer Effervescent Tablets—sodium bicarbonate, aspirin, citric acid, phenylalanine Riopan Plus—magaldrate, simethicone, sorbitol, sucrose Riopan Plus Suspension—magaldrate, simethicone, saccharin, sorbitol... 

Rationale for administering sodium bicarbonate Aspirin is a weak add, pKa = 3.5 (see text). Alkalinizing the urine by administering a weak base like sodium bicarbonate promotes the excretion of weak acids like aspirin. The Henderson-Hasselbalch equation can be used to calculate the fraction of aspirin molecules in charged and uncharged forms. 

Each Alka-Seltzer tablet contains 1916 mg of sodium bicarbonate, 1000 mg of citric acid (Fig. 9.1.2), and 325 mg of aspirin or acetylsalicylic acid (Fig. 9.1.3). Bromo Seltzer also contains sodium bicarbonate and citric acid as well as acetaminophen (Fig. 9.1.4). Several equilibria describe the action of bicarbonate-based antacid tablets. First of all, sodium bicarbonate dissolves completely in aqueous solution to generate sodium ions and bicarbonate ions ... 

The answer is a. (Hardman, pp 16-20.) Sodium bicarbonate is excreted principally in the urine and alkalinizes it. Increasing urinary pH interferes with the passive renal tubular reabsorption of organic acids (such as aspirin and phenobarbital) by increasing the ionic form of the drug in the tubular filtrate. This would increase their excretion. Excretion of organic bases (such as amphetamine, cocaine, phencyclidine, and morphine) would be enhanced by acidifying the urine. 

As mentioned in the historical synopsis (Section 5.1), Levine121 perfected the compendial partition column procedure in which aspirin in chloroform is first trapped in an immobile phase of sodium bicarbonate on a column of siliceous earth (celite) then eluted with a solution of acetic acid in chloroform and measured spectrophotometrically. This has been also used for separation in combination products.80 For the determination of salicylic acid in presence of aspirin by this method, see Section 5.61. Ion exchange columns filled with strongly or weakly basic anion exchange resin in the acetate or chloride cycle have also been used for separation of aspirin in combination products. 122 123/l2lf This has also been adapted for a student experiment.125 A Sepha-dex-G25 column has been used for the separation of aspirin from salicylic acid.126... 

Alka-Seltzer aspirin, citric acid, sodium bicarbonate... 

The antipyretic and analgesic actions of aspirin are believed to occur in a certain area of the brain. It is also thought by some that the salicylates exert their analgesia by their effect on water balance. Aspirin is anti-inflammatory because it inhibits the biosynthesis of chemicals called prostaglandins. The irritation of the stomach lining caused by aspirin can be alleviated with the use of mild bases such as sodium bicarbonate, aluminum glycinate, sodium citrate, aluminum hydroxide, or magnesium trisilicate (a common trademark for this type of aspirin is Bufferin ). 

Aspirin (salicylate) N, V, hyperventilation, noncardiac pulm edema, tinnitus, tachycardia, hypotension, tremors, blurred vision Symptomatic/supportive Urine alkalinization (sodium bicarbonate) ... 

The reactions in Table 13.8 show that carbon dioxide is a common product in many neutralization reactions. This is clearly displayed when a drop of vinegar (acetic acid) is added to baking soda (sodium bicarbonate). Some aspirin includes an antacid in their formulation to neutralize some of the acidity imparted by the aspirin (acetylsalicylic acid). These are commonly referred to as buffered aspirins. 

The supportive treatment of aspirin poisoning may include gastric lavage (to prevent the further absorption of salicylate), fluid replenishment (to offset the dehydration and oliguria), alcohol and water sponging (to combat the hyperthermia), the administration of vitamin K (to prevent possible hemorrhage), sodium bicarbonate administration (to combat acidosis) and, in extreme cases, peritoneal dialysis and exchange transfusion. 

The irritation of the stomach lining caused by aspirin can be alleviated with the use of mild bases such as sodium bicarbonate, aluminum glyci-nate, sodium citrate, aluminum hydroxide, or magnesium trisilicate (a trademark for this type of aspirin is Bufferin ). 

Test the solubility of your sample in toluene and in hot water and note the peculiar character of the aqueous solution when it is cooled and when it is then rubbed against the tube with a stirring rod. Note also that the substance dissolves in cold sodium bicarbonate solution and is precipitated by addition of an acid. Compare a tablet of commercial aspirin with your sample. Test the solubility of the tablet in water and in toluene and observe if it dissolves completely. Compare its behavior when heated in a melting point capillary with the behavior of your sample. If an impurity is found, it is probably some substance used as binder for the tablets. Is it organic or inorganic To interpret your results, consider the mechanism whereby salicylic acid is acetylated. 

Soluble, effervescent tablets are prepared by compression. In addition to active ingredients, they contain mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate (NaHCOs) that release carbon dioxide when dissolved in water. The United States Pharmacopeia (USP) 24 includes the following seven monographs Acetaminophen for Effervescent Oral Solution Aspirin Effervescent Tablets for Oral Solution Potassium Bicarbonate Effervescent Tablets for Oral Solution Potassium Bicarbonate and Potassium Chloride for Effervescent Oral Solution Potassium Bicarbonate and Potassium Chloride Effervescent Tablets for Oral Solution Potassium and Sodium Bicarbonates and Citric Acid for Oral Solution and Potassium Chloride, Potassium Bicarbonate, and Potassium Citrate Effervescent Tablets for Oral Solution. ... 

Figure 4.5 Decomposition of aspirin at elevated temperatures in tablets containing sodium bicarbonate plotted according to equation (4.41).

Alka-Seltzer aspirin sodium bicarbonate. Alkeran melphalan. allantoin [ban, usan) (glyoxylic dlureide) occurs in allantoic fluid. It is a product of purine metabolism, very widely distributed in biological systems, including numerous plants. It has antiinflammatory activity and was formerly used topically as a dermatological agent in preparations for the treatment of psoriasis and other skin conditions (though its efficacy is disputed). 

Aspirin is a carboxylic acid derivative, while paracetamol is a substituted phenol. Addition of a strong base (e.g. sodium hydroxide) would result in ionisation of both acids (and some hydrolysis of the aspirin). To separate the acids successfully, a discriminating base must therefore be used, which is formed from an acid intermediate in strength between carboxylic acids and phenols. Such an acid is carbonic acid (H2COs) and addition of sodium bicarbonate solution will result in ionisation of the aspirin as the sodium salt. This salt will be water soluble and may be removed in the lower phase. Addition of fresh organic solvent and dilute hydrochloric acid solution will yield aspirin as free acid. 

Treatment for salicylate intoxication is directed toward (1) decreasing further absorption, (2) increasing elimination, and (3) correcting add-base and electrolyte disturbances. Activated charcoal binds aspirin and prevents its absorption. Elimination of salicylate may be enhanced by alkaline diuresis and in severe cases by hemodialysis." Sodium bicarbonate may be given to alleviate metabolic acidosis. Indications for hemodialysis include serum salicylate >1000 mg/L, severe CNS depression, intractable metabolic acidosis, hepatic failure with coagulopathy, and renal failure. ... 

Recommendations for sodium bicarbonate vary (from class 1 to class in) depending on the clinical situation. Sodium bicarbonate use is acceptable for patients with known, preexisting hyperkalemia (class 1), preexisting bicarbonate-responsive acidosis (class 11a), overdoses of tricychc antidepressants (class 11a), and to aUcalinize the urine in aspirin and other drug overdoses (class 11a). In addition, sodium bicarbonate may be of benefit in intubated and ventilated patients with along arrest interval (class 11b). Sodium bicarbonate may be harmful in hypercarbic acidosis, and patients with this condition should not receive it (class IH). 

Administration of sodium bicarbonate increases the alkalinity of the tubular filtrate therefore acidic drugs, for example aspirin and barbiturates become ionized and cannot diffuse back from the tubules to the plasma. Hence their rate of elimination is increased. This may be useful in the event of an overdose. 

The acid-ether extract is shaken with a solution of sodium bicarbonate to remove the strong acids such as aspirin, then with sodium hydroxide solution to remove the weak acids, such as the barbiturates, neutral drugs such as the carbamates, and a few weak bases such as calFeine, remaining in the ether layer. 

APC tablets are a mixture of aspirin, phenacetin, and caffeine. Each of these substances has characteristic absorption in the ultraviolet region, with the principal maxima lying at 277 nm for aspirin, 275 nm for caffeine, and 250 nm for phenacetin. In the procedure, a powdered tablet is dissolved in methylene chloride, and the aspirin is separated from the phenacetin and caffeine by extracting it into aqueous sodium bicarbonate solution. The separated aspirin is back-extracted into methylene chloride by acidifying the aqueous layer and is then measured spectrophoto-metrically at 277 nm. The phenacetin and caffeine that remain in the original methylene chloride layer are determined in mixture as described in Chapter 16 (Equations 16.16 and 16.17). 

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