Acetylsalicylic tablets

Many pharmaceutical compounds contain chromophores that make them suitable for analysis by UV/Vis absorption. Products that have been analyzed in this fashion include antibiotics, hormones, vitamins, and analgesics. One example of the use of UV absorption is in determining the purity of aspirin tablets, for which the active ingredient is acetylsalicylic acid. Salicylic acid, which is produced by the hydrolysis of acetylsalicylic acid, is an undesirable impurity in aspirin tablets, and should not be present at more than 0.01% w/w. Samples can be screened for unacceptable levels of salicylic acid by monitoring the absorbance at a wavelength of... 

Several aspirin tablets are ground to a fine powder in a mortar and pestle. A 0.1013-g portion of the powder is placed in a 1-L volumetric flask and diluted to volume with distilled water. A portion of this solution is filtered to remove insoluble binders, and a 10.00-mL aliquot transferred to a 100-mL volumetric flask containing 2.00 ml of 4 M NaOH. After diluting to volume the fluorescence of the resulting solution is found to be 8.69. What is the %w/w acetylsalicylic acid in the aspirin tablets ... 

The preparation of an ion-selective electrode for salicylate is described. The electrode incorporates an ion-pair of crystal violet and salicylate in a PVC matrix as the ion-selective membrane. Its use for the determination of acetylsalicylic acid in aspirin tablets is described. A similar experiment is described by Creager, S. E. Lawrence, K. D. Tibbets, C. R. in An Easily Constructed Salicylate-Ion-Selective Electrode for Use in the Instructional Laboratory, /. Chem. Educ. 1995, 72, 274-276. 

Fig. 4 Effect of acetylsalicylic anhydride impurity on the dissolution rate of aspirin tablets. (From Ref. 34.)...

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 ... 

In the past, pharmacists measured the active ingredients in many medications in a unit called grains (gr). A grain is equal to 64.8 mg. If one headache tablet contains 5.0 gr of active acetylsalicylic acid (ASA), how many grams of ASA are in two tablets ... 

Acetylsalicylic acid Tablet Non-destructive quantitation method in three different formulations. Reflectance and transmittance modes compared 146... 

Acetylsalicylic acid Tablet Drug determination in three different formulations. Intact analysis in transmittance mode and sample grinding in reflectance mode. 148... 

P. Merckle and K.A. Kovar, Assay of effervescent tablets by near-infrared spectroscopy in transmittance and reflectance mode acetylsalicylic acid in mono and combination formulations, J. Pharm. Biomed. Anal, 17, 365-374 (1998). 

A typical aspirin tablet contains 324 mg of aspirin (acetylsalicylic acid, C9H8O4), a monoprotic acid having Ka = 3.0 X 10-4. If you dissolve two aspirin tablets in a 300 mL glass of water, what is the pH of the solution and the percent dissociation ... 

Adrug dissolution rate effect as a result of deposition of insoluble particles ora Llm on the solid surface of a tablet has been observed in at least three cases, aluminum acetylsalicylate (Levy and Sahli, 1962), benzphetamine pamoate (Higuchi and Hamlin, 1963), and tolazamide (Higuchi et al.,... 

Acetylsalicylic acid Tablet ANN Errors less than 2.5% 132... 

Tablets can easily be enteric coated, and a variety of products are available on the market, including drugs like acetylsalicylic acid, diclofenac, naproxen [40],...

J. Fogel, P. Epstein, and P. Chen, Simultaneous high-performance liquid chromatography assay of acetylsalicylic acid and salicylic acid in film-coated aspirin tablets, J. Chromatogr., 317 501 (1984). 

In the present experiment, we measure the amount of the active ingredient, acetylsalicylic acid (see also Experiment 35), in common aspirin pills. Companies use different fillers and in different amounts, but the active ingredient, acetylsalicylic acid, must be the same in every aspirin tablet. We separate the acetylsalicylic acid from the filler based on their different solubilities. Acetylsalicylic acid is very soluble in ethanol, while neither starch, nor other polysaccharides, or even mono- and disaccharides used as a fillers, are soluble in ethanol. Some companies may use inorganic salts as fillers but these too are not soluble in ethanol. On the other hand, some specially formulated aspirin tablets may contain small amounts of ethanol-soluble substances such as stearic acid or vegetable oil. Thus the ethanol extracts of aspirin tablets may contain small amounts of substances other than acetylsalicylic acid. 

APC tablet (aspirin, phenacetin, caffeine, any supplier). If these tablets are not available, a laboratory mixture may be prepared by mixing 226.8 mg of acetylsalicylic acid (aspirin), 32.4 mg of caffeine, and 162 mg of phenacetin for this experiment. This laboratory mixture will suffice as an APC tablet. ... 

No historical perspective of natural product derived drugs would be complete without a discussion of aspirin (acetylsalicylic acid)—probably the most widely utilised drug of all time when the numbers of tablets consumed worldwide on an annual basis are considered. Even today, where presumably the major pharmacological effect is modulation of the cyclooxygenase isoforms, its full activity is still not fully defined. 

Acetylsalicylic Acid-Acetaminophen-Caffeine Tablet (250mg + 250mg +... 

FIGURE 7 Dissolution profile for acetylsalicylic acid-acetaminophen-caffeine tablet (250mg + 250mg + 50mg) paddle 50rpm, 37°C deionized water. 

FIGURE 8 Enteric film coating of tablets, acetylsalicylic acid (organic solution) paddle lOOrpm, 37°C 0-2h 0.08M HC1,2h+ phosphate buffer Ph 6.8. 

---