Aspirin tablets

Normal distribution for population of aspirin tablets with p. = 250 mg aspirin and = 25. The shaded area shows the percentage of tablets containing between 243 and 262 mg of aspirin. 

A manufacturer s process for analyzing aspirin tablets has a known variance of 25. A sample of ten aspirin tablets is selected and analyzed for the amount of aspirin, yielding the following results... 

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. 

The primary health care provider has prescribed cime-tidine for the treatment of a duodenal ulcer in Mr. Talley, who is 68 years old. A drug history by the nurse reveals that Mr. Talley is also taking the following drugs Lanoxin 0.5 mg orally each day and a daily aspirin tablet. Analyze this situation. Discuss what you would tell Mr. Talley. 

RH Blythe, GM Grass, DR MacDonnell. The formulation and evaluation of enteric coated aspirin tablets. Am J Pharm 131 206-216, 1959. 

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

Long before the age of plastics and nylons, I. G. Farben-industrie was known to many Americans as simply the world s best druggist. Every reputable pharmacy, every physician s bag, every good family medicine cabinet, stocks some of Farben s 6000 medicines. The firm invented a drug that is still the best cure for epilepsy. They made atabrine, the quinine-substitute for treating malaria. And from the aspirin tablet alone, I. G. Farben made a vast fortune. 

In contrast to aspirin itself, the U.S.P. monograph for aspirin tablets has undergone considerable changes. For some reason, U.S.P. does not use the ferric salt test for free salicylic acid, as does the British Pharmacopeia of 1973. Apparently, certain excipients such as citric and tartaric acid interfere with this reaction.77 Already in 1913, a double titration method was developed78 which was made an official method in 1926.79 This method was used as the assay method when the aspirin tablets monograph was introduced into U.S.P. XII in 1942. 

That aspirin is sensitive to moisture is well-known and most of us at one time or another have observed the growth of salicylic acid whiskers on aspirin tablets left for too long in a humid bath-... 

Stability and decomposition kinetics of aspirin both as a solid and in solution continue to be studied. The topochemical decomposition pattern of aspirin tablets has been explored.175 The degradation of aspirin in the presence of sodium carbonate and high humidity was studied by x-ray diffraction.176 The activation energy of decomposition by water vapor in the solid state was found to be 30 kcal/mol.177 The effect of common tablet excipients on aspirin in aqueous suspension was also studied.178... 

Available 325 mg aspirin tablets weighing 0.7 g each, 60 mg ephedrine sulfate weighing 200 mg each, and 4 mg cpm weighing 150 mg each. 

Materials Required 20 Aspirin Tablets 0.5 N sodium hydroxide 0.5 N HC1. 

Nogami, H., Nagai, T., Fukuoka, E., and Sonobe, T., Disintegration of the aspirin tablets containing potato starch and microcrystalline cellulose in various concentrations, Chem. Pharm. Bull., 17 1450-1455 (1969). 

Number of moles of sodium hydroxide added to aspirin tablets initially = 0 0250 X 1 00 = 2-50 x lO mol... 

Even aspirin tablets that have been stored under less than ideal conditions and, therefore, have absorbed some water from the atmosphere, are likely to have suffered partial hydrolysis. The characteristic odour of acetic acid (vinegar) from a bottle of aspirin tablets will be an indicator that some hydrolysis has occurred. 

The source of the raw materials can greatly influence hydrolytic reactions. This is exemplified by Gold and Campbell [54] where talc obtained from different sources impacts markedly on the overall stability of the aspirin tablet formulation. This is possibly attributable to the effect of different types and amounts of surface impurities, which are dissolved in the adsorbed moisture layer, where they subsequently react with the API. It could also influence the pH of the micro-environment. 

The U.S. pain reliever market is estimated at 2.5 billion. Aspirin s share has recently decreased from 60% in 1983 to 28% in 1996, but this share is now stabilized. Acetaminophen has 48% of the market and ibuprofen 24%. Aspirin may be back on the upswing. After earlier reports that it was linked to Reye s syndrome in children, the recent news is that a single aspirin tablet taken every other day halves the risk of heart attacks among healthy men. 

Tablets 325 and 500 mg (ofc) Various, Genuine Bayer Aspirin Tablets and Caplets (Glenbrook), Empirin (Burroughs Wellcome), Genprin (Goldline), Maximum Bayer Aspirin Tablets and Caplets (Glenbrook), Norwich Extra-Strength (Procter Gamble Pharm.)...

In a high-pressure liquid chromatography assay of aspirin tablets, 10 extracts are made and the extracts are diluted with mobile phase solution, which consists of acetonitrile/0.1 M sodium acetate buffer pH 4.5 (10 90) and analysed sequentially. If the rate constant for the degradation of aspirin in the mobile phase is O.OfOl h " at room temperature how long can the andyst store the solutions at room temperature before the degradation of the analyte is greater than 0.5% ... 

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